Porcine MYF6 gene: sequence, homology analysis, and variation in the promoter region.

PubMed

Wyszyńska-Koko, J; Kurył, J

2004-01-01

MYF6 gene codes for the bHLH transcription factor belonging to MyoD family. Its expression accompanies the processes of differentiation and maturation of myotubes during embriogenesis and continues on a relatively high level after birth, affecting the muscle phenotype. The porcine MYF6 gene was amplified and sequenced and compared with MYF6 gene sequences of other species. The amino acid sequence was deduced and an interspecies homology analysis was performed. Myf-6 protein shows a high conservation among species of 99 and 97% identity when comparing pig with cow and human, respectively, and of 93% when comparing pig with mouse and rat. The single nucleotide polymorphism (SNP) was revealed within the promoter region, which appeared to be T --> C transition recognized by a MspI restriction enzyme.

Complete amino acid sequence of bovine colostrum low-Mr cysteine proteinase inhibitor.

PubMed

Hirado, M; Tsunasawa, S; Sakiyama, F; Niinobe, M; Fujii, S

1985-07-01

The complete amino acid sequence of bovine colostrum cysteine proteinase inhibitor was determined by sequencing native inhibitor and peptides obtained by cyanogen bromide degradation, Achromobacter lysylendopeptidase digestion and partial acid hydrolysis of reduced and S-carboxymethylated protein. Achromobacter peptidase digestion was successfully used to isolate two disulfide-containing peptides. The inhibitor consists of 112 amino acids with an Mr of 12787. Two disulfide bonds were established between Cys 66 and Cys 77 and between Cys 90 and Cys 110. A high degree of homology in the sequence was found between the colostrum inhibitor and human gamma-trace, human salivary acidic protein and chicken egg-white cystatin.

CBH1 homologs and variant CBH1 cellulases

DOEpatents

Goedegebuur, Frits [Rozenlaan, NL; Gualfetti, Peter [San Francisco, CA; Mitchinson, Colin [Half Moon Bay, CA; Neefe, Paulien [Zoetermeer, NL

2011-05-31

Disclosed are a number of homologs and variants of Hypocrea jecorina Cel7A (formerly Trichoderma reesei cellobiohydrolase I or CBH1), nucleic acids encoding the same and methods for producing the same. The homologs and variant cellulases have the amino acid sequence of a glycosyl hydrolase of family 7A wherein one or more amino acid residues are substituted and/or deleted.

CBH1 homologs and varian CBH1 cellulase

DOEpatents

Goedegebuur, Frits; Gualfetti, Peter; Mitchinson, Colin; Neefe, Paulien

2014-07-01

Disclosed are a number of homologs and variants of Hypocrea jecorina Cel7A (formerly Trichoderma reesei cellobiohydrolase I or CBH1), nucleic acids encoding the same and methods for producing the same. The homologs and variant cellulases have the amino acid sequence of a glycosyl hydrolase of family 7A wherein one or more amino acid residues are substituted and/or deleted.

The LINE-1 DNA sequences in four mammalian orders predict proteins that conserve homologies to retrovirus proteins.

PubMed Central

Fanning, T; Singer, M

1987-01-01

Recent work suggests that one or more members of the highly repeated LINE-1 (L1) DNA family found in all mammals may encode one or more proteins. Here we report the sequence of a portion of an L1 cloned from the domestic cat (Felis catus). These data permit comparison of the L1 sequences in four mammalian orders (Carnivore, Lagomorph, Rodent and Primate) and the comparison supports the suggested coding potential. In two separate, noncontiguous regions in the carboxy terminal half of the proteins predicted from the DNA sequences, there are several strongly conserved segments. In one region, these share homology with known or suspected reverse transcriptases, as described by others in rodents and primates. In the second region, closer to the carboxy terminus, the strongly conserved segments are over 90% homologous among the four orders. One of the latter segments is cysteine rich and resembles the putative metal binding domains of nucleic acid binding proteins, including those of TFIIIA and retroviruses. PMID:3562227

Adhesive proteins of stalked and acorn barnacles display homology with low sequence similarities.

PubMed

Jonker, Jaimie-Leigh; Abram, Florence; Pires, Elisabete; Varela Coelho, Ana; Grunwald, Ingo; Power, Anne Marie

2014-01-01

Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins 'sticky' has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia) by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes). It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa). Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7-16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k) showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes). Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18-26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa) are more conserved within barnacles than others (20 kDa).

Nucleic Acid Homologies Among Oxidase-Negative Moraxella Species

PubMed Central

Johnson, John L.; Anderson, Robert S.; Ordal, Erling J.

1970-01-01

The deoxyribonucleic acid (DNA) base composition and DNA homologies of more than 40 strains of oxidase-negative Moraxella species were determined. These bacteria have also been identified as belonging to the Mima-Herellea-Acinetobacter group and the Bacterium anitratum group, as well as to several other genera including Achromobacter and Alcaligenes. The DNA base content of these strains ranged from 40 to 46% guanine plus cytosine. DNA–DNA competition experiments distinguished five groups whose members were determined by showing 50% or more homology to one of the reference strains: B. anitratum type B5W, Achromobacter haemolyticus var. haemolyticus, Alcaligenes haemolysans, Achromobacter metalcaligenes, and Moraxella lwoffi. A sixth group comprised those strains showing less than 50% homology to any of the reference strains. Negligible homology was found between strains of oxidase-negative and oxidase-positive Moraxella species in DNA–DNA competition experiments. However, evidence of a distant relationship between the two groups was obtained in competition experiments by using ribosomal ribonucleic acid. PMID:5413826

The use of coded PCR primers enables high-throughput sequencing of multiple homolog amplification products by 454 parallel sequencing.

PubMed

Binladen, Jonas; Gilbert, M Thomas P; Bollback, Jonathan P; Panitz, Frank; Bendixen, Christian; Nielsen, Rasmus; Willerslev, Eske

2007-02-14

The invention of the Genome Sequence 20 DNA Sequencing System (454 parallel sequencing platform) has enabled the rapid and high-volume production of sequence data. Until now, however, individual emulsion PCR (emPCR) reactions and subsequent sequencing runs have been unable to combine template DNA from multiple individuals, as homologous sequences cannot be subsequently assigned to their original sources. We use conventional PCR with 5'-nucleotide tagged primers to generate homologous DNA amplification products from multiple specimens, followed by sequencing through the high-throughput Genome Sequence 20 DNA Sequencing System (GS20, Roche/454 Life Sciences). Each DNA sequence is subsequently traced back to its individual source through 5'tag-analysis. We demonstrate that this new approach enables the assignment of virtually all the generated DNA sequences to the correct source once sequencing anomalies are accounted for (miss-assignment rate<0.4%). Therefore, the method enables accurate sequencing and assignment of homologous DNA sequences from multiple sources in single high-throughput GS20 run. We observe a bias in the distribution of the differently tagged primers that is dependent on the 5' nucleotide of the tag. In particular, primers 5' labelled with a cytosine are heavily overrepresented among the final sequences, while those 5' labelled with a thymine are strongly underrepresented. A weaker bias also exists with regards to the distribution of the sequences as sorted by the second nucleotide of the dinucleotide tags. As the results are based on a single GS20 run, the general applicability of the approach requires confirmation. However, our experiments demonstrate that 5'primer tagging is a useful method in which the sequencing power of the GS20 can be applied to PCR-based assays of multiple homologous PCR products. The new approach will be of value to a broad range of research areas, such as those of comparative genomics, complete mitochondrial analyses

Adhesive Proteins of Stalked and Acorn Barnacles Display Homology with Low Sequence Similarities

PubMed Central

Jonker, Jaimie-Leigh; Abram, Florence; Pires, Elisabete; Varela Coelho, Ana; Grunwald, Ingo; Power, Anne Marie

2014-01-01

Barnacle adhesion underwater is an important phenomenon to understand for the prevention of biofouling and potential biotechnological innovations, yet so far, identifying what makes barnacle glue proteins ‘sticky’ has proved elusive. Examination of a broad range of species within the barnacles may be instructive to identify conserved adhesive domains. We add to extensive information from the acorn barnacles (order Sessilia) by providing the first protein analysis of a stalked barnacle adhesive, Lepas anatifera (order Lepadiformes). It was possible to separate the L. anatifera adhesive into at least 10 protein bands using SDS-PAGE. Intense bands were present at approximately 30, 70, 90 and 110 kilodaltons (kDa). Mass spectrometry for protein identification was followed by de novo sequencing which detected 52 peptides of 7–16 amino acids in length. None of the peptides matched published or unpublished transcriptome sequences, but some amino acid sequence similarity was apparent between L. anatifera and closely-related Dosima fascicularis. Antibodies against two acorn barnacle proteins (ab-cp-52k and ab-cp-68k) showed cross-reactivity in the adhesive glands of L. anatifera. We also analysed the similarity of adhesive proteins across several barnacle taxa, including Pollicipes pollicipes (a stalked barnacle in the order Scalpelliformes). Sequence alignment of published expressed sequence tags clearly indicated that P. pollicipes possesses homologues for the 19 kDa and 100 kDa proteins in acorn barnacles. Homology aside, sequence similarity in amino acid and gene sequences tended to decline as taxonomic distance increased, with minimum similarities of 18–26%, depending on the gene. The results indicate that some adhesive proteins (e.g. 100 kDa) are more conserved within barnacles than others (20 kDa). PMID:25295513

Homology and the optimization of DNA sequence data

NASA Technical Reports Server (NTRS)

Wheeler, W.

2001-01-01

Three methods of nucleotide character analysis are discussed. Their implications for molecular sequence homology and phylogenetic analysis are compared. The criterion of inter-data set congruence, both character based and topological, are applied to two data sets to elucidate and potentially discriminate among these parsimony-based ideas. c2001 The Willi Hennig Society.

Sequence homology between HLA-bound cytomegalovirus and human peptides: A potential trigger for alloreactivity

PubMed Central

Koparde, Vishal N.; Jameson-Lee, Maximilian; Elnasseh, Abdelrhman G.; Scalora, Allison F.; Kobulnicky, David J.; Serrano, Myrna G.; Roberts, Catherine H.; Buck, Gregory A.; Neale, Michael C.; Nixon, Daniel E.; Toor, Amir A.

2017-01-01

Human cytomegalovirus (hCMV) reactivation may often coincide with the development of graft-versus-host-disease (GVHD) in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n = 50; matched related donor (MRD), n = 27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (≥6) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC50<500nM) cross reactivity. Of the 70,686 hCMV 9-mers contained within the hCMV CROSS database, an average of 29,658 matched the MRD DRP alloreactive peptides and 52,910 matched MUD DRP peptides (p<0.001). In silico analysis revealed multiple high affinity, immunogenic CMV-Human peptide matches (IC50<500 nM) expressed in GVHD-affected tissue-specific manner. hCMV+GVHD was found in 18 patients, 13 developing hCMV viremia before GVHD onset. Analysis of patients with GVHD identified potential cross reactive peptide expression within affected organs. We propose that hCMV peptide sequence homology with human alloreactive peptides may contribute to the pathophysiology of GVHD. PMID:28800601

Sequence homology between HLA-bound cytomegalovirus and human peptides: A potential trigger for alloreactivity.

PubMed

Hall, Charles E; Koparde, Vishal N; Jameson-Lee, Maximilian; Elnasseh, Abdelrhman G; Scalora, Allison F; Kobulnicky, David J; Serrano, Myrna G; Roberts, Catherine H; Buck, Gregory A; Neale, Michael C; Nixon, Daniel E; Toor, Amir A

2017-01-01

Human cytomegalovirus (hCMV) reactivation may often coincide with the development of graft-versus-host-disease (GVHD) in stem cell transplantation (SCT). Seventy seven SCT donor-recipient pairs (DRP) (HLA matched unrelated donor (MUD), n = 50; matched related donor (MRD), n = 27) underwent whole exome sequencing to identify single nucleotide polymorphisms (SNPs) generating alloreactive peptide libraries for each DRP (9-mer peptide-HLA complexes); Human CMV CROSS (Cross-Reactive Open Source Sequence) database was compiled from NCBI; HLA class I binding affinity for each DRPs HLA was calculated by NetMHCpan 2.8 and hCMV- derived 9-mers algorithmically compared to the alloreactive peptide-HLA complex libraries. Short consecutive (≥6) amino acid (AA) sequence homology matching hCMV to recipient peptides was considered for HLA-bound-peptide (IC50<500nM) cross reactivity. Of the 70,686 hCMV 9-mers contained within the hCMV CROSS database, an average of 29,658 matched the MRD DRP alloreactive peptides and 52,910 matched MUD DRP peptides (p<0.001). In silico analysis revealed multiple high affinity, immunogenic CMV-Human peptide matches (IC50<500 nM) expressed in GVHD-affected tissue-specific manner. hCMV+GVHD was found in 18 patients, 13 developing hCMV viremia before GVHD onset. Analysis of patients with GVHD identified potential cross reactive peptide expression within affected organs. We propose that hCMV peptide sequence homology with human alloreactive peptides may contribute to the pathophysiology of GVHD.

Sequence-structure relationships in RNA loops: establishing the basis for loop homology modeling.

PubMed

Schudoma, Christian; May, Patrick; Nikiforova, Viktoria; Walther, Dirk

2010-01-01

The specific function of RNA molecules frequently resides in their seemingly unstructured loop regions. We performed a systematic analysis of RNA loops extracted from experimentally determined three-dimensional structures of RNA molecules. A comprehensive loop-structure data set was created and organized into distinct clusters based on structural and sequence similarity. We detected clear evidence of the hallmark of homology present in the sequence-structure relationships in loops. Loops differing by <25% in sequence identity fold into very similar structures. Thus, our results support the application of homology modeling for RNA loop model building. We established a threshold that may guide the sequence divergence-based selection of template structures for RNA loop homology modeling. Of all possible sequences that are, under the assumption of isosteric relationships, theoretically compatible with actual sequences observed in RNA structures, only a small fraction is contained in the Rfam database of RNA sequences and classes implying that the actual RNA loop space may consist of a limited number of unique loop structures and conserved sequences. The loop-structure data sets are made available via an online database, RLooM. RLooM also offers functionalities for the modeling of RNA loop structures in support of RNA engineering and design efforts.

Amino acid sequences of ribosomal proteins S11 from Bacillus stearothermophilus and S19 from Halobacterium marismortui. Comparison of the ribosomal protein S11 family.

PubMed

Kimura, M; Kimura, J; Hatakeyama, T

1988-11-21

The complete amino acid sequences of ribosomal proteins S11 from the Gram-positive eubacterium Bacillus stearothermophilus and of S19 from the archaebacterium Halobacterium marismortui have been determined. A search for homologous sequences of these proteins revealed that they belong to the ribosomal protein S11 family. Homologous proteins have previously been sequenced from Escherichia coli as well as from chloroplast, yeast and mammalian ribosomes. A pairwise comparison of the amino acid sequences showed that Bacillus protein S11 shares 68% identical residues with S11 from Escherichia coli and a slightly lower homology (52%) with the homologous chloroplast protein. The halophilic protein S19 is more related to the eukaryotic (45-49%) than to the eubacterial counterparts (35%).

Nucleotide sequence analysis of the L gene of Newcastle disease virus: homologies with Sendai and vesicular stomatitis viruses.

PubMed Central

Yusoff, K; Millar, N S; Chambers, P; Emmerson, P T

1987-01-01

The nucleotide sequence of the L gene of the Beaudette C strain of Newcastle disease virus (NDV) has been determined. The L gene is 6704 nucleotides long and encodes a protein of 2204 amino acids with a calculated molecular weight of 248822. Mung bean nuclease mapping of the 5' terminus of the L gene mRNA indicates that the transcription of the L gene is initiated 11 nucleotides upstream of the translational start site. Comparison with the amino acid sequences of the L genes of Sendai virus and vesicular stomatitis virus (VSV) suggests that there are several regions of homology between the sequences. These data provide further evidence for an evolutionary relationship between the Paramyxoviridae and the Rhabdoviridae. A non-coding sequence of 46 nucleotides downstream of the presumed polyadenylation site of the L gene may be part of a negative strand leader RNA. Images PMID:3035486

Transitive homology-guided structural studies lead to discovery of Cro proteins with 40% sequence identity but different folds

PubMed Central

Roessler, Christian G.; Hall, Branwen M.; Anderson, William J.; Ingram, Wendy M.; Roberts, Sue A.; Montfort, William R.; Cordes, Matthew H. J.

2008-01-01

Proteins that share common ancestry may differ in structure and function because of divergent evolution of their amino acid sequences. For a typical diverse protein superfamily, the properties of a few scattered members are known from experiment. A satisfying picture of functional and structural evolution in relation to sequence changes, however, may require characterization of a larger, well chosen subset. Here, we employ a “stepping-stone” method, based on transitive homology, to target sequences intermediate between two related proteins with known divergent properties. We apply the approach to the question of how new protein folds can evolve from preexisting folds and, in particular, to an evolutionary change in secondary structure and oligomeric state in the Cro family of bacteriophage transcription factors, initially identified by sequence-structure comparison of distant homologs from phages P22 and λ. We report crystal structures of two Cro proteins, Xfaso 1 and Pfl 6, with sequences intermediate between those of P22 and λ. The domains show 40% sequence identity but differ by switching of α-helix to β-sheet in a C-terminal region spanning ≈25 residues. Sedimentation analysis also suggests a correlation between helix-to-sheet conversion and strengthened dimerization. PMID:18227506

[Hepatitis C virus: sequence homology of a European isolate and divergence from the prototype].

PubMed

Seelig, R; Seelig, H P; Renz, M

1991-08-01

The polymerase chain reaction (PCR) detected specific hepatitis C viral (HCV) RNA sequences in liver biopsies from two patients with chronic hepatitis, in the tissue of a liver implantate, in plasma from four chronic non-A, non-B hepatitis (NANBH) patients and, for the first time, in an infectious anti-D-immunoglobulin preparation. A comparison of the viral sequences coding for a region for the nonstructural NS3 protein from the liver tissues revealed only a very small degree of sequence divergence on the cDNA as well as on the amino acid level (between 0 and 5%). The sequence similarities of the RNA isolated from plasma of the four chronic NANBH patients and the anti-D-immunoglobulin preparation were partly somewhat lower but altogether also high (between 90 and 100%). In contrast, all eight cDNA and amino acid sequences exhibited a significantly higher degree of divergence in comparison with the HCV prototype sequence (between 29 and 32%) than among themselves (between 0 and 10%). This unexpected high sequence similarity of the eight European isolates and their low homology to the Northamerican prototype sequence is indicative for the existence of different types of HCV. This will be important not only for epidemiological studies but also for the development of effective diagnostic procedures and vaccines. Concerning the pathogenesis of NANBH, a double infection or a helper mechanism has to be considered: in addition to the C virus, sequences of an other virus particle were found in the infectious IgG preparation as well as in the liver biopsies.

HomPPI: a class of sequence homology based protein-protein interface prediction methods

PubMed Central

2011-01-01

Background Although homology-based methods are among the most widely used methods for predicting the structure and function of proteins, the question as to whether interface sequence conservation can be effectively exploited in predicting protein-protein interfaces has been a subject of debate. Results We studied more than 300,000 pair-wise alignments of protein sequences from structurally characterized protein complexes, including both obligate and transient complexes. We identified sequence similarity criteria required for accurate homology-based inference of interface residues in a query protein sequence. Based on these analyses, we developed HomPPI, a class of sequence homology-based methods for predicting protein-protein interface residues. We present two variants of HomPPI: (i) NPS-HomPPI (Non partner-specific HomPPI), which can be used to predict interface residues of a query protein in the absence of knowledge of the interaction partner; and (ii) PS-HomPPI (Partner-specific HomPPI), which can be used to predict the interface residues of a query protein with a specific target protein. Our experiments on a benchmark dataset of obligate homodimeric complexes show that NPS-HomPPI can reliably predict protein-protein interface residues in a given protein, with an average correlation coefficient (CC) of 0.76, sensitivity of 0.83, and specificity of 0.78, when sequence homologs of the query protein can be reliably identified. NPS-HomPPI also reliably predicts the interface residues of intrinsically disordered proteins. Our experiments suggest that NPS-HomPPI is competitive with several state-of-the-art interface prediction servers including those that exploit the structure of the query proteins. The partner-specific classifier, PS-HomPPI can, on a large dataset of transient complexes, predict the interface residues of a query protein with a specific target, with a CC of 0.65, sensitivity of 0.69, and specificity of 0.70, when homologs of both the query and the

Navigating highly homologous genes in a molecular diagnostic setting: a resource for clinical next-generation sequencing.

PubMed

Mandelker, Diana; Schmidt, Ryan J; Ankala, Arunkanth; McDonald Gibson, Kristin; Bowser, Mark; Sharma, Himanshu; Duffy, Elizabeth; Hegde, Madhuri; Santani, Avni; Lebo, Matthew; Funke, Birgit

2016-12-01

Next-generation sequencing (NGS) is now routinely used to interrogate large sets of genes in a diagnostic setting. Regions of high sequence homology continue to be a major challenge for short-read technologies and can lead to false-positive and false-negative diagnostic errors. At the scale of whole-exome sequencing (WES), laboratories may be limited in their knowledge of genes and regions that pose technical hurdles due to high homology. We have created an exome-wide resource that catalogs highly homologous regions that is tailored toward diagnostic applications. This resource was developed using a mappability-based approach tailored to current Sanger and NGS protocols. Gene-level and exon-level lists delineate regions that are difficult or impossible to analyze via standard NGS. These regions are ranked by degree of affectedness, annotated for medical relevance, and classified by the type of homology (within-gene, different functional gene, known pseudogene, uncharacterized noncoding region). Additionally, we provide a list of exons that cannot be analyzed by short-amplicon Sanger sequencing. This resource can help guide clinical test design, supplemental assay implementation, and results interpretation in the context of high homology.Genet Med 18 12, 1282-1289.

GPU-Acceleration of Sequence Homology Searches with Database Subsequence Clustering.

PubMed

Suzuki, Shuji; Kakuta, Masanori; Ishida, Takashi; Akiyama, Yutaka

2016-01-01

Sequence homology searches are used in various fields and require large amounts of computation time, especially for metagenomic analysis, owing to the large number of queries and the database size. To accelerate computing analyses, graphics processing units (GPUs) are widely used as a low-cost, high-performance computing platform. Therefore, we mapped the time-consuming steps involved in GHOSTZ, which is a state-of-the-art homology search algorithm for protein sequences, onto a GPU and implemented it as GHOSTZ-GPU. In addition, we optimized memory access for GPU calculations and for communication between the CPU and GPU. As per results of the evaluation test involving metagenomic data, GHOSTZ-GPU with 12 CPU threads and 1 GPU was approximately 3.0- to 4.1-fold faster than GHOSTZ with 12 CPU threads. Moreover, GHOSTZ-GPU with 12 CPU threads and 3 GPUs was approximately 5.8- to 7.7-fold faster than GHOSTZ with 12 CPU threads.

GPU-Acceleration of Sequence Homology Searches with Database Subsequence Clustering

PubMed Central

Suzuki, Shuji; Kakuta, Masanori; Ishida, Takashi; Akiyama, Yutaka

2016-01-01

Sequence homology searches are used in various fields and require large amounts of computation time, especially for metagenomic analysis, owing to the large number of queries and the database size. To accelerate computing analyses, graphics processing units (GPUs) are widely used as a low-cost, high-performance computing platform. Therefore, we mapped the time-consuming steps involved in GHOSTZ, which is a state-of-the-art homology search algorithm for protein sequences, onto a GPU and implemented it as GHOSTZ-GPU. In addition, we optimized memory access for GPU calculations and for communication between the CPU and GPU. As per results of the evaluation test involving metagenomic data, GHOSTZ-GPU with 12 CPU threads and 1 GPU was approximately 3.0- to 4.1-fold faster than GHOSTZ with 12 CPU threads. Moreover, GHOSTZ-GPU with 12 CPU threads and 3 GPUs was approximately 5.8- to 7.7-fold faster than GHOSTZ with 12 CPU threads. PMID:27482905

Amino acid sequence of a trypsin inhibitor from a Spirometra (Spirometra erinaceieuropaei).

PubMed

Sanda, A; Uchida, A; Itagaki, T; Kobayashi, H; Inokuchi, N; Koyama, T; Iwama, M; Ohgi, K; Irie, M

2001-12-01

A trypsin inhibitor that is highly homologous with bovine pancreatic trypsin inhibitor (BPTI) was co-purified along with RNase from Spirometra (Spirometra erinaceieuropaei). The amino acid sequence of this inhibitor (SETI) and the nucleotide sequence of the cDNA encoding this protein were determined by protein chemistry and gene technology. SETI contains 68 amino acid residues and has a molecular mass of 7,798 Da. SETI has 31 amino acid residues that are identical with BPTI's sequence, including 6 half-cystine and 5 aromatic amino acid residues. The active site Lys residue in BPTI is replaced by an Arg residue in SETI. SETI is an effective inhibitor of trypsin and moderately inhibits a-chymotrypsin, but less inhibits elastase or subtilisin. SETI was expressed by E. coli containing a PelB vector carrying the SETI encoding cDNA; an expression yield of 0.68 mg/l was obtained. The phylogenetic relationship of SETI and the other BPTI-like trypsin inhibitors was analyzed using most likelihood inference methods.

Single-cell template strand sequencing by Strand-seq enables the characterization of individual homologs.

PubMed

Sanders, Ashley D; Falconer, Ester; Hills, Mark; Spierings, Diana C J; Lansdorp, Peter M

2017-06-01

The ability to distinguish between genome sequences of homologous chromosomes in single cells is important for studies of copy-neutral genomic rearrangements (such as inversions and translocations), building chromosome-length haplotypes, refining genome assemblies, mapping sister chromatid exchange events and exploring cellular heterogeneity. Strand-seq is a single-cell sequencing technology that resolves the individual homologs within a cell by restricting sequence analysis to the DNA template strands used during DNA replication. This protocol, which takes up to 4 d to complete, relies on the directionality of DNA, in which each single strand of a DNA molecule is distinguished based on its 5'-3' orientation. Culturing cells in a thymidine analog for one round of cell division labels nascent DNA strands, allowing for their selective removal during genomic library construction. To preserve directionality of template strands, genomic preamplification is bypassed and labeled nascent strands are nicked and not amplified during library preparation. Each single-cell library is multiplexed for pooling and sequencing, and the resulting sequence data are aligned, mapping to either the minus or plus strand of the reference genome, to assign template strand states for each chromosome in the cell. The major adaptations to conventional single-cell sequencing protocols include harvesting of daughter cells after a single round of BrdU incorporation, bypassing of whole-genome amplification, and removal of the BrdU + strand during Strand-seq library preparation. By sequencing just template strands, the structure and identity of each homolog are preserved.

Molecular cloning, sequence analysis and homology modeling of the first caudata amphibian antifreeze-like protein in axolotl (Ambystoma mexicanum).

PubMed

Zhang, Songyan; Gao, Jiuxiang; Lu, Yiling; Cai, Shasha; Qiao, Xue; Wang, Yipeng; Yu, Haining

2013-08-01

Antifreeze proteins (AFPs) refer to a class of polypeptides that are produced by certain vertebrates, plants, fungi, and bacteria and which permit their survival in subzero environments. In this study, we report the molecular cloning, sequence analysis and three-dimensional structure of the axolotl antifreeze-like protein (AFLP) by homology modeling of the first caudate amphibian AFLP. We constructed a full-length spleen cDNA library of axolotl (Ambystoma mexicanum). An EST having highest similarity (∼42%) with freeze-responsive liver protein Li16 from Rana sylvatica was identified, and the full-length cDNA was subsequently obtained by RACE-PCR. The axolotl antifreeze-like protein sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 93 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein were 10128.6 Da and 8.97, respectively. The molecular characterization of this gene and its deduced protein were further performed by detailed bioinformatics analysis. The three-dimensional structure of current AFLP was predicted by homology modeling, and the conserved residues required for functionality were identified. The homology model constructed could be of use for effective drug design. This is the first report of an antifreeze-like protein identified from a caudate amphibian.

Sequence basis of Barnacle Cement Nanostructure is Defined by Proteins with Silk Homology

NASA Astrophysics Data System (ADS)

So, Christopher R.; Fears, Kenan P.; Leary, Dagmar H.; Scancella, Jenifer M.; Wang, Zheng; Liu, Jinny L.; Orihuela, Beatriz; Rittschof, Dan; Spillmann, Christopher M.; Wahl, Kathryn J.

2016-11-01

Barnacles adhere by producing a mixture of cement proteins (CPs) that organize into a permanently bonded layer displayed as nanoscale fibers. These cement proteins share no homology with any other marine adhesives, and a common sequence-basis that defines how nanostructures function as adhesives remains undiscovered. Here we demonstrate that a significant unidentified portion of acorn barnacle cement is comprised of low complexity proteins; they are organized into repetitive sequence blocks and found to maintain homology to silk motifs. Proteomic analysis of aggregate bands from PAGE gels reveal an abundance of Gly/Ala/Ser/Thr repeats exemplified by a prominent, previously unidentified, 43 kDa protein in the solubilized adhesive. Low complexity regions found throughout the cement proteome, as well as multiple lysyl oxidases and peroxidases, establish homology with silk-associated materials such as fibroin, silk gum sericin, and pyriform spidroins from spider silk. Distinct primary structures defined by homologous domains shed light on how barnacles use low complexity in nanofibers to enable adhesion, and serves as a starting point for unraveling the molecular architecture of a robust and unique class of adhesive nanostructures.

The vector homology problem in diagnostic nucleic acid hybridization of clinical specimens.

PubMed Central

Ambinder, R F; Charache, P; Staal, S; Wright, P; Forman, M; Hayward, S D; Hayward, G S

1986-01-01

Nucleic acid hybridization techniques using cloned probes are finding application in assays of clinical specimens in research and diagnostic laboratories. The probes that we and others have used are recombinant plasmids composed of viral inserts and bacterial plasmid vectors such as pBR322. We suspected that there was material homologous to pBR322 present in many clinical samples. because hybridization occurred in samples which lacked evidence of virus by other techniques. If the presence of this vector-homologous material was unrecognized, hybridization in the test sample might erroneously be interpreted as indicating the presence of viral sequences. In this paper we demonstrate specific hybridization of labeled pBR322 DNA with DNA from various clinical samples. Evidence is presented that nonspecific probe trapping could not account for this phenomenon. In mixing experiments, it is shown that contamination of clinical samples with bacteria would explain such a result. Approaches tested to circumvent this problem included the use of isolated insert probes, alternate cloning vectors, and cold competitor pBR322 DNA in prehybridization and hybridization mixes. None proved entirely satisfactory. We therefore emphasize that it is essential that all hybridization detection systems use a control probe of the vector alone in order to demonstrate the absence of material with vector homology in the specimen tested. Images PMID:3013928

Amino acid sequences of the ribosomal proteins HL30 and HmaL5 from the archaebacterium Halobacterium marismortui.

PubMed

Hatakeyama, T; Hatakeyama, T

1990-07-06

The complete amino acid sequences of the ribosomal proteins HL30 and HmaL5 from the archaebacterium Halobacterium marismortui were determined. Protein HL30 was found to be acetylated at its N-terminal amino acid and shows homology to the eukaryotic ribosomal proteins YL34 from yeast and RL31 from rat. Protein HmaL5 was homologous to the protein L5 from Escherichia coli and Bacillus stearothermophilus as well as to YL16 from yeast. HmaL5 shows more similarities to its eukaryotic counterpart than to eubacterial ones.

VITAL NMR: Using Chemical Shift Derived Secondary Structure Information for a Limited Set of Amino Acids to Assess Homology Model Accuracy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brothers, Michael C; Nesbitt, Anna E; Hallock, Michael J

2011-01-01

Homology modeling is a powerful tool for predicting protein structures, whose success depends on obtaining a reasonable alignment between a given structural template and the protein sequence being analyzed. In order to leverage greater predictive power for proteins with few structural templates, we have developed a method to rank homology models based upon their compliance to secondary structure derived from experimental solid-state NMR (SSNMR) data. Such data is obtainable in a rapid manner by simple SSNMR experiments (e.g., (13)C-(13)C 2D correlation spectra). To test our homology model scoring procedure for various amino acid labeling schemes, we generated a library ofmore » 7,474 homology models for 22 protein targets culled from the TALOS+/SPARTA+ training set of protein structures. Using subsets of amino acids that are plausibly assigned by SSNMR, we discovered that pairs of the residues Val, Ile, Thr, Ala and Leu (VITAL) emulate an ideal dataset where all residues are site specifically assigned. Scoring the models with a predicted VITAL site-specific dataset and calculating secondary structure with the Chemical Shift Index resulted in a Pearson correlation coefficient (-0.75) commensurate to the control (-0.77), where secondary structure was scored site specifically for all amino acids (ALL 20) using STRIDE. This method promises to accelerate structure procurement by SSNMR for proteins with unknown folds through guiding the selection of remotely homologous protein templates and assessing model quality.« less

Homology between DNA polymerases of poxviruses, herpesviruses, and adenoviruses: nucleotide sequence of the vaccinia virus DNA polymerase gene.

PubMed Central

Earl, P L; Jones, E V; Moss, B

1986-01-01

A 5400-base-pair segment of the vaccinia virus genome was sequenced and an open reading frame of 938 codons was found precisely where the DNA polymerase had been mapped by transfer of a phosphonoacetate-resistance marker. A single nucleotide substitution changing glycine at position 347 to aspartic acid accounts for the drug resistance of the mutant vaccinia virus. The 5' end of the DNA polymerase mRNA was located 80 base pairs before the methionine codon initiating the open reading frame. Correspondence between the predicted Mr 108,577 polypeptide and the 110,000 purified enzyme indicates that little or no proteolytic processing occurs. Extensive homology, extending over 435 amino acids, was found upon comparing the DNA polymerase of vaccinia virus and DNA polymerase of Epstein-Barr virus. A highly conserved sequence of 14 amino acids in the carboxyl-terminal regions of the above DNA polymerases is also present at a similar location in adenovirus DNA polymerase. This structure, which is predicted to form a turn flanked by beta-pleated sheets, may form part of an essential binding or catalytic site that accounts for its presence in DNA polymerases of poxviruses, herpesviruses, and adenoviruses. Images PMID:3012524

The amino acid sequence around the active-site cysteine and histidine residues of stem bromelain

PubMed Central

Husain, S. S.; Lowe, G.

1970-01-01

Stem bromelain that had been irreversibly inhibited with 1,3-dibromo[2-14C]-acetone was reduced with sodium borohydride and carboxymethylated with iodoacetic acid. After digestion with trypsin and α-chymotrypsin three radioactive peptides were isolated chromatographically. The amino acid sequences around the cross-linked cysteine and histidine residues were determined and showed a high degree of homology with those around the active-site cysteine and histidine residues of papain and ficin. PMID:5420046

EUGENE'HOM: A generic similarity-based gene finder using multiple homologous sequences.

PubMed

Foissac, Sylvain; Bardou, Philippe; Moisan, Annick; Cros, Marie-Josée; Schiex, Thomas

2003-07-01

EUGENE'HOM is a gene prediction software for eukaryotic organisms based on comparative analysis. EUGENE'HOM is able to take into account multiple homologous sequences from more or less closely related organisms. It integrates the results of TBLASTX analysis, splice site and start codon prediction and a robust coding/non-coding probabilistic model which allows EUGENE'HOM to handle sequences from a variety of organisms. The current target of EUGENE'HOM is plant sequences. The EUGENE'HOM web site is available at http://genopole.toulouse.inra.fr/bioinfo/eugene/EuGeneHom/cgi-bin/EuGeneHom.pl.

PSI/TM-Coffee: a web server for fast and accurate multiple sequence alignments of regular and transmembrane proteins using homology extension on reduced databases.

PubMed

Floden, Evan W; Tommaso, Paolo D; Chatzou, Maria; Magis, Cedrik; Notredame, Cedric; Chang, Jia-Ming

2016-07-08

The PSI/TM-Coffee web server performs multiple sequence alignment (MSA) of proteins by combining homology extension with a consistency based alignment approach. Homology extension is performed with Position Specific Iterative (PSI) BLAST searches against a choice of redundant and non-redundant databases. The main novelty of this server is to allow databases of reduced complexity to rapidly perform homology extension. This server also gives the possibility to use transmembrane proteins (TMPs) reference databases to allow even faster homology extension on this important category of proteins. Aside from an MSA, the server also outputs topological prediction of TMPs using the HMMTOP algorithm. Previous benchmarking of the method has shown this approach outperforms the most accurate alignment methods such as MSAProbs, Kalign, PROMALS, MAFFT, ProbCons and PRALINE™. The web server is available at http://tcoffee.crg.cat/tmcoffee. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

On the necessity of dissecting sequence similarity scores into segment-specific contributions for inferring protein homology, function prediction and annotation

PubMed Central

2014-01-01

Background Protein sequence similarities to any types of non-globular segments (coiled coils, low complexity regions, transmembrane regions, long loops, etc. where either positional sequence conservation is the result of a very simple, physically induced pattern or rather integral sequence properties are critical) are pertinent sources for mistaken homologies. Regretfully, these considerations regularly escape attention in large-scale annotation studies since, often, there is no substitute to manual handling of these cases. Quantitative criteria are required to suppress events of function annotation transfer as a result of false homology assignments. Results The sequence homology concept is based on the similarity comparison between the structural elements, the basic building blocks for conferring the overall fold of a protein. We propose to dissect the total similarity score into fold-critical and other, remaining contributions and suggest that, for a valid homology statement, the fold-relevant score contribution should at least be significant on its own. As part of the article, we provide the DissectHMMER software program for dissecting HMMER2/3 scores into segment-specific contributions. We show that DissectHMMER reproduces HMMER2/3 scores with sufficient accuracy and that it is useful in automated decisions about homology for instructive sequence examples. To generalize the dissection concept for cases without 3D structural information, we find that a dissection based on alignment quality is an appropriate surrogate. The approach was applied to a large-scale study of SMART and PFAM domains in the space of seed sequences and in the space of UniProt/SwissProt. Conclusions Sequence similarity core dissection with regard to fold-critical and other contributions systematically suppresses false hits and, additionally, recovers previously obscured homology relationships such as the one between aquaporins and formate/nitrite transporters that, so far, was only

Tracing the Evolutionary History of the CAP Superfamily of Proteins Using Amino Acid Sequence Homology and Conservation of Splice Sites.

PubMed

Abraham, Anup; Chandler, Douglas E

2017-10-01

Proteins of the CAP superfamily play numerous roles in reproduction, innate immune responses, cancer biology, and venom toxicology. Here we document the breadth of the CAP (Cysteine-RIch Secretory Protein (CRISP), Antigen 5, and Pathogenesis-Related) protein superfamily and trace the major events in its evolution using amino acid sequence homology and the positions of exon/intron borders within their genes. Seldom acknowledged in the literature, we find that many of the CAP subfamilies present in mammals, where they were originally characterized, have distinct homologues in the invertebrate phyla. Early eukaryotic CAP genes contained only one exon inherited from prokaryotic predecessors and as evolution progressed an increasing number of introns were inserted, reaching 2-5 in the invertebrate world and 5-15 in the vertebrate world. Focusing on the CRISP subfamily, we propose that these proteins evolved in three major steps: (1) origination of the CAP/PR/SCP domain in bacteria, (2) addition of a small Hinge domain to produce the two-domain SCP-like proteins found in roundworms and anthropoids, and (3) addition of an Ion Channel Regulatory domain, borrowed from invertebrate peptide toxins, to produce full length, three-domain CRISP proteins, first seen in insects and later to diversify into multiple subtypes in the vertebrate world.

alpha-Amylase gene of Streptomyces limosus: nucleotide sequence, expression motifs, and amino acid sequence homology to mammalian and invertebrate alpha-amylases.

PubMed Central

Long, C M; Virolle, M J; Chang, S Y; Chang, S; Bibb, M J

1987-01-01

The nucleotide sequence of the coding and regulatory regions of the alpha-amylase gene (aml) of Streptomyces limosus was determined. High-resolution S1 mapping was used to locate the 5' end of the transcript and demonstrated that the gene is transcribed from a unique promoter. The predicted amino acid sequence has considerable identity to mammalian and invertebrate alpha-amylases, but not to those of plant, fungal, or eubacterial origin. Consistent with this is the susceptibility of the enzyme to an inhibitor of mammalian alpha-amylases. The amino-terminal sequence of the extracellular enzyme was determined, revealing the presence of a typical signal peptide preceding the mature form of the alpha-amylase. Images PMID:3500166

Hydroquinone: O-glucosyltransferase from cultivated Rauvolfia cells: enrichment and partial amino acid sequences.

PubMed

Arend, J; Warzecha, H; Stöckigt, J

2000-01-01

Plant cell suspension cultures of Rauvolfia are able to produce a high amount of arbutin by glucosylation of exogenously added hydroquinone. A four step purification procedure using anion exchange, hydrophobic interaction, hydroxyapatite-chromatography and chromatofocusing delivered in a yield of 0.5%, an approximately 390 fold enrichment of the involved glucosyltransferase. SDS-PAGE showed a M(r) for the enzyme of 52 kDa. Proteolysis of the pure enzyme with endoproteinase LysC revealed six peptide fragments with 9-23 amino acids which were sequenced. Sequence alignment of the six peptides showed high homologies to glycosyltransferases from other higher plants.

CPHmodels-3.0--remote homology modeling using structure-guided sequence profiles.

PubMed

Nielsen, Morten; Lundegaard, Claus; Lund, Ole; Petersen, Thomas Nordahl

2010-07-01

CPHmodels-3.0 is a web server predicting protein 3D structure by use of single template homology modeling. The server employs a hybrid of the scoring functions of CPHmodels-2.0 and a novel remote homology-modeling algorithm. A query sequence is first attempted modeled using the fast CPHmodels-2.0 profile-profile scoring function suitable for close homology modeling. The new computational costly remote homology-modeling algorithm is only engaged provided that no suitable PDB template is identified in the initial search. CPHmodels-3.0 was benchmarked in the CASP8 competition and produced models for 94% of the targets (117 out of 128), 74% were predicted as high reliability models (87 out of 117). These achieved an average RMSD of 4.6 A when superimposed to the 3D structure. The remaining 26% low reliably models (30 out of 117) could superimpose to the true 3D structure with an average RMSD of 9.3 A. These performance values place the CPHmodels-3.0 method in the group of high performing 3D prediction tools. Beside its accuracy, one of the important features of the method is its speed. For most queries, the response time of the server is <20 min. The web server is available at http://www.cbs.dtu.dk/services/CPHmodels/.

Sequence homology and structural analysis of plasmepsin 4 isolated from Indian Plasmodium vivax isolates.

PubMed

Rawat, Manmeet; Vijay, Sonam; Gupta, Yash; Dixit, Rajnikant; Tiwari, P K; Sharma, Arun

2011-07-01

Plasmodium vivax malaria is a globally widespread disease responsible for 50% of human malaria cases in Central and South America, South East Asia and Indian subcontinent. The rising severity of the disease and emerging resistance of the parasite has emphasized the need for the search of novel therapeutic targets to combat P. vivax malaria. Plasmepsin 4 (PM4) a food vacuole aspartic protease is essential in parasite functions and viability such as initiating hemoglobin digestion and processing of proteins and is being looked upon as potential drug target. Although the plasmepsins of Plasmodium falciparum have been extensively studied, the plasmepsins of P. vivax are not well characterized. This is the first report detailing complete PM4 gene analysis from Indian P. vivax isolates. Blast results of sequences of P. vivax plasmepsin 4 (PvPM4) shows 100% homology among isolates of P. vivax collected from different geographical regions of India. All of the seven Indian isolates did not contain intron within the coding region. Interestingly, PvPM4 sequence analysis showed a very high degree of homology with all other sequences of Plasmodium species available in the genebank. Our results strongly suggest that PvPM4 are highly conserved except a small number of amino acid substitutions that did not modify key motifs at active site formation for the function or the structure of the enzymes. Furthermore, our study shows that PvPM4 occupies unique phylogenetic status within Plasmodium group and sufficiently differ from the most closely related human aspartic protease, cathepsin D. The analysis of 3D model of PM4 showed a typical aspartic protease structure with bi-lobed, compact and distinct peptide binding cleft in both P. vivax and P. falciparum. In order to validate appropriate use of PM4 as potential anti-malarial drug target, studies on genetic and structural variations among P. vivax plasmepsins (PvPMs) from different geographical regions are of utmost importance for

The catalytic activity for ginkgolic acid biodegradation, homology modeling and molecular dynamic simulation of salicylic acid decarboxylase.

PubMed

Hu, Yanying; Hua, Qingyuan; Sun, Guojuan; Shi, Kunpeng; Zhang, Huitu; Zhao, Kai; Jia, Shiru; Dai, Yujie; Wu, Qingli

2018-05-02

The toxic ginkgolic acids are the main safety concern for the application of Ginkgo biloba. In this study, the degradation ability of salicylic acid decarboxylase (SDC) for ginkgolic acids was examined using ginkgolic acid C15:1 as a substrate. The results indicated that the content of ginkgolic acid C15:1 in Ginkgo biloba seeds was significantly decreased after 5 h treatment with SDC at 40 °Cand pH 5.5. In order to explore the structure of SDC and the interaction between SDC and substrates, homology modeling, molecular docking and molecular dynamics were performed. The results showed that SDC might also have a catalytic active center containing a Zn 2+ . Compared with the template structure of 2,6-dihydroxybenzoate decarboxylase, the residues surrounding the binding pocket, His10, Phe23 and Phe290, were replaced by Ala10, Tyr27 and Tyr301 in the homology constructed structure of SDC, respectively. These differences may significantly affect the substrates adaptability of SDC for salicylic acid derivatives. Copyright © 2018 Elsevier Ltd. All rights reserved.

CMsearch: simultaneous exploration of protein sequence space and structure space improves not only protein homology detection but also protein structure prediction.

PubMed

Cui, Xuefeng; Lu, Zhiwu; Wang, Sheng; Jing-Yan Wang, Jim; Gao, Xin

2016-06-15

Protein homology detection, a fundamental problem in computational biology, is an indispensable step toward predicting protein structures and understanding protein functions. Despite the advances in recent decades on sequence alignment, threading and alignment-free methods, protein homology detection remains a challenging open problem. Recently, network methods that try to find transitive paths in the protein structure space demonstrate the importance of incorporating network information of the structure space. Yet, current methods merge the sequence space and the structure space into a single space, and thus introduce inconsistency in combining different sources of information. We present a novel network-based protein homology detection method, CMsearch, based on cross-modal learning. Instead of exploring a single network built from the mixture of sequence and structure space information, CMsearch builds two separate networks to represent the sequence space and the structure space. It then learns sequence-structure correlation by simultaneously taking sequence information, structure information, sequence space information and structure space information into consideration. We tested CMsearch on two challenging tasks, protein homology detection and protein structure prediction, by querying all 8332 PDB40 proteins. Our results demonstrate that CMsearch is insensitive to the similarity metrics used to define the sequence and the structure spaces. By using HMM-HMM alignment as the sequence similarity metric, CMsearch clearly outperforms state-of-the-art homology detection methods and the CASP-winning template-based protein structure prediction methods. Our program is freely available for download from http://sfb.kaust.edu.sa/Pages/Software.aspx : xin.gao@kaust.edu.sa Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

Not all transmembrane helices are born equal: Towards the extension of the sequence homology concept to membrane proteins

PubMed Central

2011-01-01

Background Sequence homology considerations widely used to transfer functional annotation to uncharacterized protein sequences require special precautions in the case of non-globular sequence segments including membrane-spanning stretches composed of non-polar residues. Simple, quantitative criteria are desirable for identifying transmembrane helices (TMs) that must be included into or should be excluded from start sequence segments in similarity searches aimed at finding distant homologues. Results We found that there are two types of TMs in membrane-associated proteins. On the one hand, there are so-called simple TMs with elevated hydrophobicity, low sequence complexity and extraordinary enrichment in long aliphatic residues. They merely serve as membrane-anchoring device. In contrast, so-called complex TMs have lower hydrophobicity, higher sequence complexity and some functional residues. These TMs have additional roles besides membrane anchoring such as intra-membrane complex formation, ligand binding or a catalytic role. Simple and complex TMs can occur both in single- and multi-membrane-spanning proteins essentially in any type of topology. Whereas simple TMs have the potential to confuse searches for sequence homologues and to generate unrelated hits with seemingly convincing statistical significance, complex TMs contain essential evolutionary information. Conclusion For extending the homology concept onto membrane proteins, we provide a necessary quantitative criterion to distinguish simple TMs (and a sufficient criterion for complex TMs) in query sequences prior to their usage in homology searches based on assessment of hydrophobicity and sequence complexity of the TM sequence segments. Reviewers This article was reviewed by Shamil Sunyaev, L. Aravind and Arcady Mushegian. PMID:22024092

Full genome virus detection in fecal samples using sensitive nucleic acid preparation, deep sequencing, and a novel iterative sequence classification algorithm.

PubMed

Cotten, Matthew; Oude Munnink, Bas; Canuti, Marta; Deijs, Martin; Watson, Simon J; Kellam, Paul; van der Hoek, Lia

2014-01-01

We have developed a full genome virus detection process that combines sensitive nucleic acid preparation optimised for virus identification in fecal material with Illumina MiSeq sequencing and a novel post-sequencing virus identification algorithm. Enriched viral nucleic acid was converted to double-stranded DNA and subjected to Illumina MiSeq sequencing. The resulting short reads were processed with a novel iterative Python algorithm SLIM for the identification of sequences with homology to known viruses. De novo assembly was then used to generate full viral genomes. The sensitivity of this process was demonstrated with a set of fecal samples from HIV-1 infected patients. A quantitative assessment of the mammalian, plant, and bacterial virus content of this compartment was generated and the deep sequencing data were sufficient to assembly 12 complete viral genomes from 6 virus families. The method detected high levels of enteropathic viruses that are normally controlled in healthy adults, but may be involved in the pathogenesis of HIV-1 infection and will provide a powerful tool for virus detection and for analyzing changes in the fecal virome associated with HIV-1 progression and pathogenesis.

Full Genome Virus Detection in Fecal Samples Using Sensitive Nucleic Acid Preparation, Deep Sequencing, and a Novel Iterative Sequence Classification Algorithm

PubMed Central

Cotten, Matthew; Oude Munnink, Bas; Canuti, Marta; Deijs, Martin; Watson, Simon J.; Kellam, Paul; van der Hoek, Lia

2014-01-01

We have developed a full genome virus detection process that combines sensitive nucleic acid preparation optimised for virus identification in fecal material with Illumina MiSeq sequencing and a novel post-sequencing virus identification algorithm. Enriched viral nucleic acid was converted to double-stranded DNA and subjected to Illumina MiSeq sequencing. The resulting short reads were processed with a novel iterative Python algorithm SLIM for the identification of sequences with homology to known viruses. De novo assembly was then used to generate full viral genomes. The sensitivity of this process was demonstrated with a set of fecal samples from HIV-1 infected patients. A quantitative assessment of the mammalian, plant, and bacterial virus content of this compartment was generated and the deep sequencing data were sufficient to assembly 12 complete viral genomes from 6 virus families. The method detected high levels of enteropathic viruses that are normally controlled in healthy adults, but may be involved in the pathogenesis of HIV-1 infection and will provide a powerful tool for virus detection and for analyzing changes in the fecal virome associated with HIV-1 progression and pathogenesis. PMID:24695106

GAWK, a novel human pituitary polypeptide: isolation, immunocytochemical localization and complete amino acid sequence.

PubMed

Benjannet, S; Leduc, R; Lazure, C; Seidah, N G; Marcinkiewicz, M; Chrétien, M

1985-01-16

During the course of reverse-phase high pressure liquid chromatography (RP-HPLC) purification of a postulated big ACTH (1) from human pituitary gland extracts, a highly purified peptide bearing no resemblance to any known polypeptide was isolated. The complete sequence of this 74 amino acid polypeptide, called GAWK, has been determined. Search on a computer data bank on the possible homology to any known protein or fragment, using a mutation data matrix, failed to reveal any homology greater than 30%. An antibody produced against a synthetic fragment allowed us to detect several immunoreactive forms. The antisera also enabled us to localize the polypeptide, by immunocytochemistry, in the anterior lobe of the pituitary gland.

EUGÈNE'HOM: a generic similarity-based gene finder using multiple homologous sequences

PubMed Central

Foissac, Sylvain; Bardou, Philippe; Moisan, Annick; Cros, Marie-Josée; Schiex, Thomas

2003-01-01

EUGÈNE'HOM is a gene prediction software for eukaryotic organisms based on comparative analysis. EUGÈNE'HOM is able to take into account multiple homologous sequences from more or less closely related organisms. It integrates the results of TBLASTX analysis, splice site and start codon prediction and a robust coding/non-coding probabilistic model which allows EUGÈNE'HOM to handle sequences from a variety of organisms. The current target of EUGÈNE'HOM is plant sequences. The EUGÈNE'HOM web site is available at http://genopole.toulouse.inra.fr/bioinfo/eugene/EuGeneHom/cgi-bin/EuGeneHom.pl. PMID:12824408

Composition for nucleic acid sequencing

DOEpatents

Korlach, Jonas [Ithaca, NY; Webb, Watt W [Ithaca, NY; Levene, Michael [Ithaca, NY; Turner, Stephen [Ithaca, NY; Craighead, Harold G [Ithaca, NY; Foquet, Mathieu [Ithaca, NY

2008-08-26

The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

Solid phase sequencing of biopolymers

DOEpatents

Cantor, Charles; Koster, Hubert

2010-09-28

This invention relates to methods for detecting and sequencing target nucleic acid sequences, to mass modified nucleic acid probes and arrays of probes useful in these methods, and to kits and systems which contain these probes. Useful methods involve hybridizing the nucleic acids or nucleic acids which represent complementary or homologous sequences of the target to an array of nucleic acid probes. These probes comprise a single-stranded portion, an optional double-stranded portion and a variable sequence within the single-stranded portion. The molecular weights of the hybridized nucleic acids of the set can be determined by mass spectroscopy, and the sequence of the target determined from the molecular weights of the fragments. Nucleic acids whose sequences can be determined include DNA or RNA in biological samples such as patient biopsies and environmental samples. Probes may be fixed to a solid support such as a hybridization chip to facilitate automated molecular weight analysis and identification of the target sequence.

The sequence, and its evolutionary implications, of a Thermococcus celer protein associated with transcription

NASA Technical Reports Server (NTRS)

Kaine, B. P.; Mehr, I. J.; Woese, C. R.

1994-01-01

Through random search, a gene from Thermococcus celer has been identified and sequenced that appears to encode a transcription-associated protein (110 amino acid residues). The sequence has clear homology to approximately the last half of an open reading frame reported previously for Sulfolobus acidocaldarius [Langer, D. & Zillig, W. (1993) Nucleic Acids Res. 21, 2251]. The protein translations of these two archaeal genes in turn are homologs of a small subunit found in eukaryotic RNA polymerase I (A12.2) and the counterpart of this from RNA polymerase II (B12.6). Homology is also seen with the eukaryotic transcription factor TFIIS, but it involves only the terminal 45 amino acids of the archaeal proteins. Evolutionary implications of these homologies are discussed.

Chip-based sequencing nucleic acids

DOEpatents

Beer, Neil Reginald

2014-08-26

A system for fast DNA sequencing by amplification of genetic material within microreactors, denaturing, demulsifying, and then sequencing the material, while retaining it in a PCR/sequencing zone by a magnetic field. One embodiment includes sequencing nucleic acids on a microchip that includes a microchannel flow channel in the microchip. The nucleic acids are isolated and hybridized to magnetic nanoparticles or to magnetic polystyrene-coated beads. Microreactor droplets are formed in the microchannel flow channel. The microreactor droplets containing the nucleic acids and the magnetic nanoparticles are retained in a magnetic trap in the microchannel flow channel and sequenced.

Streptococcal phosphoenolpyruvate-sugar phosphotransferase system: amino acid sequence and site of ATP-dependent phosphorylation of HPr

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deutscher, J.; Pevec, B.; Beyreuther, K.

1986-10-21

The amino acid sequence of histidine-containing protein (HPr) from Streptococcus faecalis has been determined by direct Edman degradation of intact HPr and by amino acid sequence analysis of tryptic peptides, V8 proteolyptic peptides, thermolytic peptides, and cyanogen bromide cleavage products. HPr from S. faecalis was found to contain 89 amino acid residues, corresponding to a molecular weight of 9438. The amino acid sequence of HPr from S. faecalis shows extended homology to the primary structure of HPr proteins from other bacteria. Besides the phosphoenolpyruvate-dependent phosphorylation of a histidyl residue in HPr, catalyzed by enzyme I of the bacterial phosphotransferase system,more » HPr was also found to be phosphorylated at a seryl residue in an ATP-dependent protein kinase catalyzed reaction. The site of ATP-dependent phosphorylation in HPr of S faecalis has now been determined. (/sup 32/P)P-Ser-HPr was digested with three different proteases, and in each case, a single labeled peptide was isolated. Following digestion with subtilisin, they obtained a peptide with the sequence -(P)Ser-Ile-Met-. Using chymotrypsin, they isolated a peptide with the sequence -Ser-Val-Asn-Leu-Lys-(P)Ser-Ile-Met-Gly-Val-Met-. The longest labeled peptide was obtained with V8 staphylococcal protease. According to amino acid analysis, this peptide contained 36 out of the 89 amino acid residues of HPr. The following sequence of 12 amino acid residues of the V8 peptide was determined: -Tyr-Lys-Gly-Lys-Ser-Val-Asn-Leu-Lys-(P)Ser-Ile-Met-. Thus, the site of ATP-dependent phosphorylation was determined to be Ser-46 within the primary structure of HPr.« less

Complete amino acid sequences of the ribosomal proteins L25, L29 and L31 from the archaebacterium Halobacterium marismortui.

PubMed

Hatakeyama, T; Kimura, M

1988-03-15

Ribosomal proteins were extracted from 50S ribosomal subunits of the archaebacterium Halobacterium marismortui by decreasing the concentration of Mg2+ and K+, and the proteins were separated and purified by ion-exchange column chromatography on DEAE-cellulose. Ten proteins were purified to homogeneity and three of these proteins were subjected to sequence analysis. The complete amino acid sequences of the ribosomal proteins L25, L29 and L31 were established by analyses of the peptides obtained by enzymatic digestion with trypsin, Staphylococcus aureus protease, chymotrypsin and lysylendopeptidase. Proteins L25, L29 and L31 consist of 84, 115 and 95 amino acid residues with the molecular masses of 9472 Da, 12293 Da and 10418 Da respectively. A comparison of their sequences with those of other large-ribosomal-subunit proteins from other organisms revealed that protein L25 from H. marismortui is homologous to protein L23 from Escherichia coli (34.6%), Bacillus stearothermophilus (41.8%), and tobacco chloroplasts (16.3%) as well as to protein L25 from yeast (38.0%). Proteins L29 and L31 do not appear to be homologous to any other ribosomal proteins whose structures are so far known.

SNBRFinder: A Sequence-Based Hybrid Algorithm for Enhanced Prediction of Nucleic Acid-Binding Residues.

PubMed

Yang, Xiaoxia; Wang, Jia; Sun, Jun; Liu, Rong

2015-01-01

Protein-nucleic acid interactions are central to various fundamental biological processes. Automated methods capable of reliably identifying DNA- and RNA-binding residues in protein sequence are assuming ever-increasing importance. The majority of current algorithms rely on feature-based prediction, but their accuracy remains to be further improved. Here we propose a sequence-based hybrid algorithm SNBRFinder (Sequence-based Nucleic acid-Binding Residue Finder) by merging a feature predictor SNBRFinderF and a template predictor SNBRFinderT. SNBRFinderF was established using the support vector machine whose inputs include sequence profile and other complementary sequence descriptors, while SNBRFinderT was implemented with the sequence alignment algorithm based on profile hidden Markov models to capture the weakly homologous template of query sequence. Experimental results show that SNBRFinderF was clearly superior to the commonly used sequence profile-based predictor and SNBRFinderT can achieve comparable performance to the structure-based template methods. Leveraging the complementary relationship between these two predictors, SNBRFinder reasonably improved the performance of both DNA- and RNA-binding residue predictions. More importantly, the sequence-based hybrid prediction reached competitive performance relative to our previous structure-based counterpart. Our extensive and stringent comparisons show that SNBRFinder has obvious advantages over the existing sequence-based prediction algorithms. The value of our algorithm is highlighted by establishing an easy-to-use web server that is freely accessible at http://ibi.hzau.edu.cn/SNBRFinder.

Partial amino acid sequence of the branched chain amino acid aminotransferase (TmB) of E. coli JA199 pDU11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feild, M.J.; Armstrong, F.B.

1987-05-01

E. coli JA199 pDU11 harbors a multicopy plasmid containing the ilv GEDAY gene cluster of S. typhimurium. TmB, gene product of ilv E, was purified, crystallized, and subjected to Edman degradation using a gas phase sequencer. The intact protein yielded an amino terminal 31 residue sequence. Both carboxymethylated apoenzyme and (/sup 3/H)-NaBH-reduced holoenzyme were then subjected to digestion by trypsin. The digests were fractionated using reversed phase HPLC, and the peptides isolated were sequenced. The borohydride-treated holoenzyme was used to isolate the cofactor-binding peptide. The peptide is 27 residues long and a comparison with known sequences of other aminotransferases revealedmore » limited homology. Peptides accounting for 211 of 288 predicted residues have been sequenced, including 9 residues of the carboxyl terminus. Comparison of peptides with the inferred amino acid sequence of the E. coli K-12 enzyme has helped determine the sequence of the amino terminal 59 residues; only two differences between the sequences are noted in this region.« less

SANSparallel: interactive homology search against Uniprot.

PubMed

Somervuo, Panu; Holm, Liisa

2015-07-01

Proteins evolve by mutations and natural selection. The network of sequence similarities is a rich source for mining homologous relationships that inform on protein structure and function. There are many servers available to browse the network of homology relationships but one has to wait up to a minute for results. The SANSparallel webserver provides protein sequence database searches with immediate response and professional alignment visualization by third-party software. The output is a list, pairwise alignment or stacked alignment of sequence-similar proteins from Uniprot, UniRef90/50, Swissprot or Protein Data Bank. The stacked alignments are viewed in Jalview or as sequence logos. The database search uses the suffix array neighborhood search (SANS) method, which has been re-implemented as a client-server, improved and parallelized. The method is extremely fast and as sensitive as BLAST above 50% sequence identity. Benchmarks show that the method is highly competitive compared to previously published fast database search programs: UBLAST, DIAMOND, LAST, LAMBDA, RAPSEARCH2 and BLAT. The web server can be accessed interactively or programmatically at http://ekhidna2.biocenter.helsinki.fi/cgi-bin/sans/sans.cgi. It can be used to make protein functional annotation pipelines more efficient, and it is useful in interactive exploration of the detailed evidence supporting the annotation of particular proteins of interest. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Next-Generation Sequence Analysis of the Genome of RFHVMn, the Macaque Homolog of Kaposi's Sarcoma (KS)-Associated Herpesvirus, from a KS-Like Tumor of a Pig-Tailed Macaque

PubMed Central

Bruce, A. Gregory; Ryan, Jonathan T.; Thomas, Mathew J.; Peng, Xinxia; Grundhoff, Adam; Tsai, Che-Chung

2013-01-01

The complete sequence of retroperitoneal fibromatosis-associated herpesvirus Macaca nemestrina (RFHVMn), the pig-tailed macaque homolog of Kaposi's sarcoma-associated herpesvirus (KSHV), was determined by next-generation sequence analysis of a Kaposi's sarcoma (KS)-like macaque tumor. Colinearity of genes was observed with the KSHV genome, and the core herpesvirus genes had strong sequence homology to the corresponding KSHV genes. RFHVMn lacked homologs of open reading frame 11 (ORF11) and KSHV ORFs K5 and K6, which appear to have been generated by duplication of ORFs K3 and K4 after the divergence of KSHV and RFHV. RFHVMn contained positional homologs of all other unique KSHV genes, although some showed limited sequence similarity. RFHVMn contained a number of candidate microRNA genes. Although there was little sequence similarity with KSHV microRNAs, one candidate contained the same seed sequence as the positional homolog, kshv-miR-K12-10a, suggesting functional overlap. RNA transcript splicing was highly conserved between RFHVMn and KSHV, and strong sequence conservation was noted in specific promoters and putative origins of replication, predicting important functional similarities. Sequence comparisons indicated that RFHVMn and KSHV developed in long-term synchrony with the evolution of their hosts, and both viruses phylogenetically group within the RV1 lineage of Old World primate rhadinoviruses. RFHVMn is the closest homolog of KSHV to be completely sequenced and the first sequenced RV1 rhadinovirus homolog of KSHV from a nonhuman Old World primate. The strong genetic and sequence similarity between RFHVMn and KSHV, coupled with similarities in biology and pathology, demonstrate that RFHVMn infection in macaques offers an important and relevant model for the study of KSHV in humans. PMID:24109218

Initial cloning and sequencing of hydHG, an operon homologous to ntrBC and regulating the labile hydrogenase activity in Escherichia coli K-12.

PubMed Central

Stoker, K; Reijnders, W N; Oltmann, L F; Stouthamer, A H

1989-01-01

To isolate genes from Escherichia coli which regulate the labile hydrogenase activity, a plasmid library was used to transform hydL mutants lacking the labile hydrogenase. A single type of gene, designated hydG, was isolated. This gene also partially restored the hydrogenase activity in hydF mutants (which are defective in all hydrogenase isoenzymes), although the low hydrogenase 1 and 2 levels were not induced. Therefore, hydG apparently regulates, specifically, the labile hydrogenase activity. Restoration of this latter activity in hydF mutants was accompanied by a proportional increase of the H2 uptake activity, suggesting a functional relationship. H2:fumarate oxidoreductase activity was not restored in complemented hydL mutants. These latter strains may therefore lack, in addition to the labile hydrogenase, a second component (provisionally designated component R), possibly an electron carrier coupling H2 oxidation to the anerobic respiratory chain. Sequence analysis showed an open reading frame of 1,314 base pairs for hydG. It was preceded by a ribosome-binding site but apparently lacked a promoter. Minicell experiments revealed a single polypeptide of approximately 50 kilodaltons. Comparison of the predicted amino acid sequence with a protein sequence data base revealed strong homology to NtrC from Klebsiella pneumoniae, a DNA-binding transcriptional activator. The 411 base pairs upstream from pHG40 contained a second open reading frame overlapping hydG by four bases. The deduced amino acid sequence showed considerable homology with the C-terminal part of NtrB. This sequence was therefore assumed to be part of a second gene, encoding the NtrB-like component, and was designated hydH. The labile hydrogenase activity in E. coli is apparently regulated by a multicomponent system analogous to the NtrB-NtrC system. This conclusion is in agreement with the results of Birkmann et al. (A. Birkmann, R. G. Sawers, and A. Böck, Mol. Gen. Genet. 210:535-542, 1987), who

Comparative analysis of ribosomal protein L5 sequences from bacteria of the genus Thermus.

PubMed

Jahn, O; Hartmann, R K; Boeckh, T; Erdmann, V A

1991-06-01

The genes for the ribosomal 5S rRNA binding protein L5 have been cloned from three extremely thermophilic eubacteria, Thermus flavus, Thermus thermophilus HB8 and Thermus aquaticus (Jahn et al, submitted). Genes for protein L5 from the three Thermus strains display 95% G/C in third positions of codons. Amino acid sequences deduced from the DNA sequence were shown to be identical for T flavus and T thermophilus, although the corresponding DNA sequences differed by two T to C transitions in the T thermophilus gene. Protein L5 sequences from T flavus and T thermophilus are 95% homologous to L5 from T aquaticus and 56.5% homologous to the corresponding E coli sequence. The lowest degrees of homology were found between the T flavus/T thermophilus L5 proteins and those of yeast L16 (27.5%), Halobacterium marismortui (34.0%) and Methanococcus vannielii (36.6%). From sequence comparison it becomes clear that thermostability of Thermus L5 proteins is achieved by an increase in hydrophobic interactions and/or by restriction of steric flexibility due to the introduction of amino acids with branched aliphatic side chains such as leucine. Alignment of the nine protein sequences equivalent to Thermus L5 proteins led to identification of a conserved internal segment, rich in acidic amino acids, which shows homology to subsequences of E coli L18 and L25. The occurrence of conserved sequence elements in 5S rRNA binding proteins and ribosomal proteins in general is discussed in terms of evolution and function.

Biosynthesis of Lipoic Acid in Arabidopsis: Cloning and Characterization of the cDNA for Lipoic Acid Synthase1

PubMed Central

Yasuno, Rie; Wada, Hajime

1998-01-01

Lipoic acid is a coenzyme that is essential for the activity of enzyme complexes such as those of pyruvate dehydrogenase and glycine decarboxylase. We report here the isolation and characterization of LIP1 cDNA for lipoic acid synthase of Arabidopsis. The Arabidopsis LIP1 cDNA was isolated using an expressed sequence tag homologous to the lipoic acid synthase of Escherichia coli. This cDNA was shown to code for Arabidopsis lipoic acid synthase by its ability to complement a lipA mutant of E. coli defective in lipoic acid synthase. DNA-sequence analysis of the LIP1 cDNA revealed an open reading frame predicting a protein of 374 amino acids. Comparisons of the deduced amino acid sequence with those of E. coli and yeast lipoic acid synthase homologs showed a high degree of sequence similarity and the presence of a leader sequence presumably required for import into the mitochondria. Southern-hybridization analysis suggested that LIP1 is a single-copy gene in Arabidopsis. Western analysis with an antibody against lipoic acid synthase demonstrated that this enzyme is located in the mitochondrial compartment in Arabidopsis cells as a 43-kD polypeptide. PMID:9808738

Heterochromatic self-association, a determinant of nuclear organization, does not require sequence homology in Drosophila.

PubMed Central

Sage, Brian T; Csink, Amy K

2003-01-01

Chromosomes of higher eukaryotes contain blocks of heterochromatin that can associate with each other in the interphase nucleus. A well-studied example of heterochromatic interaction is the brown(Dominant) (bwD) chromosome of D. melanogaster, which contains an approximately 1.6-Mbp insertion of AAGAG repeats near the distal tip of chromosome 2. This insertion causes association of the tip with the centric heterochromatin of chromosome 2 (2h), which contains megabases of AAGAG repeats. Here we describe an example, other than bwD, in which distally translocated heterochromatin associates with centric heterochromatin. Additionally, we show that when a translocation places bwD on a different chromosome, bwD tends to associate with the centric heterochromatin of this chromosome, even when the chromosome contains a small fraction of the sequence homology present elsewhere. To further test the importance of sequence homology in these interactions, we used interspecific mating to introgress the bwD allele from D. melanogaster into D. simulans, which lacks the AAGAG on the autosomes. We find that D. simulans bwD associates with 2h, which lacks the AAGAG sequence, while it does not associate with the AAGAG containing X chromosome heterochromatin. Our results show that intranuclear association of separate heterochromatic blocks does not require that they contain the same sequence. PMID:14668374

MIPS: a database for protein sequences, homology data and yeast genome information.

PubMed Central

Mewes, H W; Albermann, K; Heumann, K; Liebl, S; Pfeiffer, F

1997-01-01

The MIPS group (Martinsried Institute for Protein Sequences) at the Max-Planck-Institute for Biochemistry, Martinsried near Munich, Germany, collects, processes and distributes protein sequence data within the framework of the tripartite association of the PIR-International Protein Sequence Database (,). MIPS contributes nearly 50% of the data input to the PIR-International Protein Sequence Database. The database is distributed on CD-ROM together with PATCHX, an exhaustive supplement of unique, unverified protein sequences from external sources compiled by MIPS. Through its WWW server (http://www.mips.biochem.mpg.de/ ) MIPS permits internet access to sequence databases, homology data and to yeast genome information. (i) Sequence similarity results from the FASTA program () are stored in the FASTA database for all proteins from PIR-International and PATCHX. The database is dynamically maintained and permits instant access to FASTA results. (ii) Starting with FASTA database queries, proteins have been classified into families and superfamilies (PROT-FAM). (iii) The HPT (hashed position tree) data structure () developed at MIPS is a new approach for rapid sequence and pattern searching. (iv) MIPS provides access to the sequence and annotation of the complete yeast genome (), the functional classification of yeast genes (FunCat) and its graphical display, the 'Genome Browser' (). A CD-ROM based on the JAVA programming language providing dynamic interactive access to the yeast genome and the related protein sequences has been compiled and is available on request. PMID:9016498

Method for sequencing nucleic acid molecules

DOEpatents

Korlach, Jonas; Webb, Watt W.; Levene, Michael; Turner, Stephen; Craighead, Harold G.; Foquet, Mathieu

2006-06-06

The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

Method for sequencing nucleic acid molecules

DOEpatents

Korlach, Jonas; Webb, Watt W.; Levene, Michael; Turner, Stephen; Craighead, Harold G.; Foquet, Mathieu

2006-05-30

The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

Implication of the cause of differences in 3D structures of proteins with high sequence identity based on analyses of amino acid sequences and 3D structures.

PubMed

Matsuoka, Masanari; Sugita, Masatake; Kikuchi, Takeshi

2014-09-18

Proteins that share a high sequence homology while exhibiting drastically different 3D structures are investigated in this study. Recently, artificial proteins related to the sequences of the GA and IgG binding GB domains of human serum albumin have been designed. These artificial proteins, referred to as GA and GB, share 98% amino acid sequence identity but exhibit different 3D structures, namely, a 3α bundle versus a 4β + α structure. Discriminating between their 3D structures based on their amino acid sequences is a very difficult problem. In the present work, in addition to using bioinformatics techniques, an analysis based on inter-residue average distance statistics is used to address this problem. It was hard to distinguish which structure a given sequence would take only with the results of ordinary analyses like BLAST and conservation analyses. However, in addition to these analyses, with the analysis based on the inter-residue average distance statistics and our sequence tendency analysis, we could infer which part would play an important role in its structural formation. The results suggest possible determinants of the different 3D structures for sequences with high sequence identity. The possibility of discriminating between the 3D structures based on the given sequences is also discussed.

KM+, a mannose-binding lectin from Artocarpus integrifolia: amino acid sequence, predicted tertiary structure, carbohydrate recognition, and analysis of the beta-prism fold.

PubMed Central

Rosa, J. C.; De Oliveira, P. S.; Garratt, R.; Beltramini, L.; Resing, K.; Roque-Barreira, M. C.; Greene, L. J.

1999-01-01

The complete amino acid sequence of the lectin KM+ from Artocarpus integrifolia (jackfruit), which contains 149 residues/mol, is reported and compared to those of other members of the Moraceae family, particularly that of jacalin, also from jackfruit, with which it shares 52% sequence identity. KM+ presents an acetyl-blocked N-terminus and is not posttranslationally modified by proteolytic cleavage as is the case for jacalin. Rather, it possesses a short, glycine-rich linker that unites the regions homologous to the alpha- and beta-chains of jacalin. The results of homology modeling implicate the linker sequence in sterically impeding rotation of the side chain of Asp141 within the binding site pocket. As a consequence, the aspartic acid is locked into a conformation adequate only for the recognition of equatorial hydroxyl groups on the C4 epimeric center (alpha-D-mannose, alpha-D-glucose, and their derivatives). In contrast, the internal cleavage of the jacalin chain permits free rotation of the homologous aspartic acid, rendering it capable of accepting hydrogen bonds from both possible hydroxyl configurations on C4. We suggest that, together with direct recognition of epimeric hydroxyls and the steric exclusion of disfavored ligands, conformational restriction of the lectin should be considered to be a new mechanism by which selectivity may be built into carbohydrate binding sites. Jacalin and KM+ adopt the beta-prism fold already observed in two unrelated protein families. Despite presenting little or no sequence similarity, an analysis of the beta-prism reveals a canonical feature repeatedly present in all such structures, which is based on six largely hydrophobic residues within a beta-hairpin containing two classic-type beta-bulges. We suggest the term beta-prism motif to describe this feature. PMID:10210179

Unequal homologous recombination between tandemly arranged sequences stably incorporated into cultured rat cells.

PubMed Central

Stringer, J R; Kuhn, R M; Newman, J L; Meade, J C

1985-01-01

Cultured rat cells deficient in endogenous thymidine kinase activity (tk) were stably transformed with a recombination-indicator DNA substrate constructed in vitro by rearrangement of the herpes simplex virus tk gene sequences into a partially redundant permutation of the functional gene. The recombination-indicator DNA did not express tk, but was designed to allow formation of a functional tk gene via homologous recombination. A clonal cell line (519) was isolated that harbored several permuted herpes simplex virus tk genes. 519 cells spontaneously produced progeny that survived in medium containing hypoxanthine, aminopterin, and thymidine. Acquisition of resistance to hypoxanthine, aminopterin, and thymidine was accompanied by the rearrangement of the defective tk gene to functional configuration. The rearrangement apparently occurred by unequal exchange between one permuted tk gene and a replicated copy of itself. Recombination was between 500-base-pair tracts of DNA sequence homology that were separated by 3.4 kilobases. Exchanges occurred spontaneously at a frequency of approximately 5 X 10(-6) events per cell per generation. Recombination also mediated reversion to the tk- phenotype; however, the predominant mechanism by which cells escaped death in the presence of drugs rendered toxic by thymidine kinase was not recombination, but rather inactivation of the intact tk gene. Images PMID:3016511

Redesigning Aldolase Stereoselectivity by Homologous Grafting.

PubMed

Bisterfeld, Carolin; Classen, Thomas; Küberl, Irene; Henßen, Birgit; Metz, Alexander; Gohlke, Holger; Pietruszka, Jörg

2016-01-01

The 2-deoxy-d-ribose-5-phosphate aldolase (DERA) offers access to highly desirable building blocks for organic synthesis by catalyzing a stereoselective C-C bond formation between acetaldehyde and certain electrophilic aldehydes. DERA´s potential is particularly highlighted by the ability to catalyze sequential, highly enantioselective aldol reactions. However, its synthetic use is limited by the absence of an enantiocomplementary enzyme. Here, we introduce the concept of homologous grafting to identify stereoselectivity-determining amino acid positions in DERA. We identified such positions by structural analysis of the homologous aldolases 2-keto-3-deoxy-6-phosphogluconate aldolase (KDPG) and the enantiocomplementary enzyme 2-keto-3-deoxy-6-phosphogalactonate aldolase (KDPGal). Mutation of these positions led to a slightly inversed enantiopreference of both aldolases to the same extent. By transferring these sequence motifs onto DERA we achieved the intended change in enantioselectivity.

Nucleotide sequence of the gene encoding the nitrogenase iron protein of Thiobacillus ferrooxidans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pretorius, I.M.; Rawlings, D.E.; O'Neill, E.G.

1987-01-01

The DNA sequence was determined for the cloned Thiobacillus ferrooxidans nifH and part of the nifD genes. The DNA chains were radiolabeled with (..cap alpha..-/sup 32/P)dCTP (3000 Ci/mmol) or (..cap alpha..-/sup 35/S)dCTP (400 Ci/mmol). A putative T. ferrooxidans nifH promoter was identified whose sequences showed perfect consensus with those of the Klebsiella pneumoniae nif promoter. Two putative consensus upstream activator sequences were also identified. The amino acid sequence was deduced from the DNA sequence. In a comparison of nifH DNA sequences from T. ferrooxidans and eight other nitrogen-fixing microbes, a Rhizobium sp. isolated from Parasponia andersonii showed the greatest homologymore » (74%) and Clostridium pasteurianum (nifH1) showed the least homology (54%). In the comparison of the amino acid sequences of the Fe proteins, the Rhizobium sp. and Rhizobium japonicum showed the greatest homology (both 86%) and C. pasteurianum (nifH1 gene product) demonstrated the least homology (56%) to the T. ferrooxidans Fe protein.« less

DNA Repair: The Search for Homology.

PubMed

Haber, James E

2018-05-01

The repair of chromosomal double-strand breaks (DSBs) by homologous recombination is essential to maintain genome integrity. The key step in DSB repair is the RecA/Rad51-mediated process to match sequences at the broken end to homologous donor sequences that can be used as a template to repair the lesion. Here, in reviewing research about DSB repair, I consider the many factors that appear to play important roles in the successful search for homology by several homologous recombination mechanisms. See also the video abstract here: https://youtu.be/vm7-X5uIzS8. © 2018 WILEY Periodicals, Inc.

Amino- and carboxyl-terminal amino acid sequences of proteins coded by gag gene of murine leukemia virus

PubMed Central

Oroszlan, Stephen; Henderson, Louis E.; Stephenson, John R.; Copeland, Terry D.; Long, Cedric W.; Ihle, James N.; Gilden, Raymond V.

1978-01-01

The amino- and carboxyl-terminal amino acid sequences of proteins (p10, p12, p15, and p30) coded by the gag gene of Rauscher and AKR murine leukemia viruses were determined. Among these proteins, p15 from both viruses appears to have a blocked amino end. Proline was found to be the common NH2 terminus of both p30s and both p12s, and alanine of both p10s. The amino-terminal sequences of p30s are identical, as are those of p10s, while the p12 sequences are clearly distinctive but also show substantial homology. The carboxyl-terminal amino acids of both viral p30s and p12s are leucine and phenylalanine, respectively. Rauscher leukemia virus p15 has tyrosine as the carboxyl terminus while AKR virus p15 has phenylalanine in this position. The compositional and sequence data provide definite chemical criteria for the identification of analogous gag gene products and for the comparison of viral proteins isolated in different laboratories. On the basis of amino acid sequences and the previously proposed H-p15-p12-p30-p10-COOH peptide sequence in the precursor polyprotein, a model for cleavage sites involved in the post-translational processing of the precursor coded for by the gag gene is proposed. PMID:206897

Method for identifying and quantifying nucleic acid sequence aberrations

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

1998-01-01

A method for detecting nucleic acid sequence aberrations by detecting nucleic acid sequences having both a first and a second nucleic acid sequence type, the presence of the first and second sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. The method uses a first hybridization probe which includes a nucleic acid sequence that is complementary to a first sequence type and a first complexing agent capable of attaching to a second complexing agent and a second hybridization probe which includes a nucleic acid sequence that selectively hybridizes to the second nucleic acid sequence type over the first sequence type and includes a detectable marker for detecting the second hybridization probe.

Cloning and characterization of the ddc homolog encoding L-2,4-diaminobutyrate decarboxylase in Enterobacter aerogenes.

PubMed

Yamamoto, S; Mutoh, N; Tsuzuki, D; Ikai, H; Nakao, H; Shinoda, S; Narimatsu, S; Miyoshi, S I

2000-05-01

L-2,4-diaminobutyrate decarboxylase (DABA DC) catalyzes the formation of 1,3-diaminopropane (DAP) from DABA. In the present study, the ddc gene encoding DABA DC from Enterobacter aerogenes ATCC 13048 was cloned and characterized. Determination of the nucleotide sequence revealed an open reading frame of 1470 bp encoding a 53659-Da protein of 490 amino acids, whose deduced NH2-terminal sequence was identical to that of purified DABA DC from E. aerogenes. The deduced amino acid sequence was highly similar to those of Acinetobacter baumannii and Haemophilus influenzae DABA DCs encoded by the ddc genes. The lysine-307 of the E. aerogenes DABA DC was identified as the pyridoxal 5'-phosphate binding residue by site-directed mutagenesis. Furthermore, PCR analysis revealed the distribution of E. aerogenes ddc homologs in some other species of Enterobacteriaceae. Such a relatively wide occurrence of the ddc homologs implies biological significance of DABA DC and its product DAP.

Comparative analysis of the prion protein gene sequences in African lion.

PubMed

Wu, Chang-De; Pang, Wan-Yong; Zhao, De-Ming

2006-10-01

The prion protein gene of African lion (Panthera Leo) was first cloned and polymorphisms screened. The results suggest that the prion protein gene of eight African lions is highly homogenous. The amino acid sequences of the prion protein (PrP) of all samples tested were identical. Four single nucleotide polymorphisms (C42T, C81A, C420T, T600C) in the prion protein gene (Prnp) of African lion were found, but no amino acid substitutions. Sequence analysis showed that the higher homology is observed to felis catus AF003087 (96.7%) and to sheep number M31313.1 (96.2%) Genbank accessed. With respect to all the mammalian prion protein sequences compared, the African lion prion protein sequence has three amino acid substitutions. The homology might in turn affect the potential intermolecular interactions critical for cross species transmission of prion disease.

Method for identifying and quantifying nucleic acid sequence aberrations

DOEpatents

Lucas, J.N.; Straume, T.; Bogen, K.T.

1998-07-21

A method is disclosed for detecting nucleic acid sequence aberrations by detecting nucleic acid sequences having both a first and a second nucleic acid sequence type, the presence of the first and second sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. The method uses a first hybridization probe which includes a nucleic acid sequence that is complementary to a first sequence type and a first complexing agent capable of attaching to a second complexing agent and a second hybridization probe which includes a nucleic acid sequence that selectively hybridizes to the second nucleic acid sequence type over the first sequence type and includes a detectable marker for detecting the second hybridization probe. 11 figs.

Nucleotide sequence determination of guinea-pig casein B mRNA reveals homology with bovine and rat alpha s1 caseins and conservation of the non-coding regions of the mRNA.

PubMed Central

Hall, L; Laird, J E; Craig, R K

1984-01-01

Nucleotide sequence analysis of cloned guinea-pig casein B cDNA sequences has identified two casein B variants related to the bovine and rat alpha s1 caseins. Amino acid homology was largely confined to the known bovine or predicted rat phosphorylation sites and within the 'signal' precursor sequence. Comparison of the deduced nucleotide sequence of the guinea-pig and rat alpha s1 casein mRNA species showed greater sequence conservation in the non-coding than in the coding regions, suggesting a functional and possibly regulatory role for the non-coding regions of casein mRNA. The results provide insight into the evolution of the casein genes, and raise questions as to the role of conserved nucleotide sequences within the non-coding regions of mRNA species. Images Fig. 1. PMID:6548375

Comparative genomic survey, exon-intron annotation and phylogenetic analysis of NAT-homologous sequences in archaea, protists, fungi, viruses, and invertebrates

USDA-ARS?s Scientific Manuscript database

We have previously published extensive genomic surveys [1-3], reporting NAT-homologous sequences in hundreds of sequenced bacterial, fungal and vertebrate genomes. We present here the results of our latest search of 2445 genomes, representing 1532 (70 archaeal, 1210 bacterial, 43 protist, 97 fungal,...

DNA homology among diverse spiroplasma strains representing several serological groups.

PubMed

Lee, I M; Davis, R E

1980-11-01

Deoxyribonucleic acid (DNA) homology among 10 strains of spiroplasma associated with plants and insects was assessed by analysis of DNA-DNA hybrids with single strand specific S1 nuclease. Based on DNA homology, the spiroplasmas could be divided into three genetically distinct groups (designated I, II, and III), corresponding to three separate serogroups described previously. DNA sequence homology between the three groups was less than or equal to 5%. Based on DNA homology, group I could be divided into three subgroups (A, B, and C) that corresponded to three serological subgroups of serogroup I. Subgroup A contained Spiroplasma citri strains Maroc R8A2 and C 189; subgroup B contained strains AS 576 from honey bee and G 1 from flowers; subgroup C contained corn stunt spiroplasma strains I-747 and PU 8-17. There was 27-54% DNA sequence homology among these three subgroups. Group II contained strains 23-6 and 27-31 isolated from flowers of tulip tree (Liriodendron tulipifera L.). Group III contained strains SR 3 and SR 9, other isolates from flowers of tulip tree. Based on thermal denaturation, guanine plus cytosine contents of DNA from five type strains representing all groups and subgroups were estimated to be close to 26 mol% for group I strains, close to 25 mol% for group II strains, and close to 29 mol% for group III strains. The genome molecular weights of these five type strains were all estimated to bae about 10(9).

Top-Down-Assisted Bottom-Up Method for Homologous Protein Sequencing: Hemoglobin from 33 Bird Species

NASA Astrophysics Data System (ADS)

Song, Yang; Laskay, Ünige A.; Vilcins, Inger-Marie E.; Barbour, Alan G.; Wysocki, Vicki H.

2015-11-01

Ticks are vectors for disease transmission because they are indiscriminant in their feeding on multiple vertebrate hosts, transmitting pathogens between their hosts. Identifying the hosts on which ticks have fed is important for disease prevention and intervention. We have previously shown that hemoglobin (Hb) remnants from a host on which a tick fed can be used to reveal the host's identity. For the present research, blood was collected from 33 bird species that are common in the U.S. as hosts for ticks but that have unknown Hb sequences. A top-down-assisted bottom-up mass spectrometry approach with a customized searching database, based on variability in known bird hemoglobin sequences, has been devised to facilitate fast and complete sequencing of hemoglobin from birds with unknown sequences. These hemoglobin sequences will be added to a hemoglobin database and used for tick host identification. The general approach has the potential to sequence any set of homologous proteins completely in a rapid manner.

Protein conformation and disease : pathological consequences of analogous mutations in homologous proteins.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, F. J.; Pokkuluri, P. R.; Schiffer, M.

2000-12-19

The antibody light chain variable domain (V{sub L}){sup 1} and myelin protein zero (MPZ) are representatives of the functionally diverse immunoglobulin superfamily. The V{sub L} is a subunit of the antigen-binding component of antibodies, while MPZ is the major membrane-linked constituent of the myelin sheaths that coat peripheral nerves. Despite limited amino acid sequence homology, the conformations of the core structures of the two proteins are largely superimposable. Amino acid variations in V{sub L} account for various conformational disease outcomes, including amyloidosis. However, the specific amino acid changes in V{sub L} that are responsible for disease have been obscured bymore » multiple concurrent primary structure alterations. Recently, certain demyelination disorders have been linked to point mutations and single amino acid polymorphisms in MPZ. We demonstrate here that some pathogenic variations in MPZ correspond to changes suspected of determining amyloidosis in V{sub L}. This unanticipated observation suggests that studies of the biophysical origin of conformational disease in one member of a superfamily of homologous proteins may have implications throughout the superfamily. In some cases, findings may account for overt disease; in other cases, due to the natural repertoire of inherited polymorphisms, variations in a representative protein may predict subclinical impairment of homologous proteins.« less

PARRoT- a homology-based strategy to quantify and compare RNA-sequencing from non-model organisms.

PubMed

Gan, Ruei-Chi; Chen, Ting-Wen; Wu, Timothy H; Huang, Po-Jung; Lee, Chi-Ching; Yeh, Yuan-Ming; Chiu, Cheng-Hsun; Huang, Hsien-Da; Tang, Petrus

2016-12-22

Next-generation sequencing promises the de novo genomic and transcriptomic analysis of samples of interests. However, there are only a few organisms having reference genomic sequences and even fewer having well-defined or curated annotations. For transcriptome studies focusing on organisms lacking proper reference genomes, the common strategy is de novo assembly followed by functional annotation. However, things become even more complicated when multiple transcriptomes are compared. Here, we propose a new analysis strategy and quantification methods for quantifying expression level which not only generate a virtual reference from sequencing data, but also provide comparisons between transcriptomes. First, all reads from the transcriptome datasets are pooled together for de novo assembly. The assembled contigs are searched against NCBI NR databases to find potential homolog sequences. Based on the searched result, a set of virtual transcripts are generated and served as a reference transcriptome. By using the same reference, normalized quantification values including RC (read counts), eRPKM (estimated RPKM) and eTPM (estimated TPM) can be obtained that are comparable across transcriptome datasets. In order to demonstrate the feasibility of our strategy, we implement it in the web service PARRoT. PARRoT stands for Pipeline for Analyzing RNA Reads of Transcriptomes. It analyzes gene expression profiles for two transcriptome sequencing datasets. For better understanding of the biological meaning from the comparison among transcriptomes, PARRoT further provides linkage between these virtual transcripts and their potential function through showing best hits in SwissProt, NR database, assigning GO terms. Our demo datasets showed that PARRoT can analyze two paired-end transcriptomic datasets of approximately 100 million reads within just three hours. In this study, we proposed and implemented a strategy to analyze transcriptomes from non-reference organisms which offers

Epitopes of human testis-specific lactate dehydrogenase deduced from a cDNA sequence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millan, J.L.; Driscoll, C.E.; LeVan, K.M.

The sequence and structure of human testis-specific L-lactate dehydrogenase (LDHC/sub 4/, LDHX; (L)-lactate:NAD/sup +/ oxidoreductase, EC 1.1.1.27) has been derived from analysis of a complementary DNA (cDNA) clone comprising the complete protein coding region of the enzyme. From the deduced amino acid sequence, human LDHC/sub 4/ is as different from rodent LDHC/sub 4/ (73% homology) as it is from human LDHA/sub 4/ (76% homology) and porcine LDHB/sub 4/ (68% homology). Subunit homologies are consistent with the conclusion that the LDHC gene arose by at least two independent duplication events. Furthermore, the lower degree of homology between mouse and human LDHC/submore » 4/ and the appearance of this isozyme late in evolution suggests a higher rate of mutation in the mammalian LDHC genes than in the LDHA and -B genes. Comparison of exposed amino acid residues of discrete anti-genic determinants of mouse and human LDHC/sub 4/ reveals significant differences. Knowledge of the human LDHC/sub 4/ sequence will help design human-specific peptides useful in the development of a contraceptive vaccine.« less

A putative carbohydrate-binding domain of the lactose-binding Cytisus sessilifolius anti-H(O) lectin has a similar amino acid sequence to that of the L-fucose-binding Ulex europaeus anti-H(O) lectin.

PubMed

Konami, Y; Yamamoto, K; Osawa, T; Irimura, T

1995-04-01

The complete amino acid sequence of a lactose-binding Cytisus sessilifolius anti-H(O) lectin II (CSA-II) was determined using a protein sequencer. After digestion of CSA-II with endoproteinase Lys-C or Asp-N, the resulting peptides were purified by reversed-phase high performance liquid chromatography (HPLC) and then subjected to sequence analysis. Comparison of the complete amino acid sequence of CSA-II with the sequences of other leguminous seed lectins revealed regions of extensive homology. The amino acid sequence of a putative carbohydrate-binding domain of CSA-II was found to be similar to those of several anti-H(O) leguminous lectins, especially to that of the L-fucose-binding Ulex europaeus lectin I (UEA-I).

The OGCleaner: filtering false-positive homology clusters.

PubMed

Fujimoto, M Stanley; Suvorov, Anton; Jensen, Nicholas O; Clement, Mark J; Snell, Quinn; Bybee, Seth M

2017-01-01

Detecting homologous sequences in organisms is an essential step in protein structure and function prediction, gene annotation and phylogenetic tree construction. Heuristic methods are often employed for quality control of putative homology clusters. These heuristics, however, usually only apply to pairwise sequence comparison and do not examine clusters as a whole. We present the Orthology Group Cleaner (the OGCleaner), a tool designed for filtering putative orthology groups as homology or non-homology clusters by considering all sequences in a cluster. The OGCleaner relies on high-quality orthologous groups identified in OrthoDB to train machine learning algorithms that are able to distinguish between true-positive and false-positive homology groups. This package aims to improve the quality of phylogenetic tree construction especially in instances of lower-quality transcriptome assemblies. https://github.com/byucsl/ogcleaner CONTACT: sfujimoto@gmail.comSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Osteoblast-specific factor 2: cloning of a putative bone adhesion protein with homology with the insect protein fasciclin I.

PubMed Central

Takeshita, S; Kikuno, R; Tezuka, K; Amann, E

1993-01-01

A cDNA library prepared from the mouse osteoblastic cell line MC3T3-E1 was screened for the presence of specifically expressed genes by employing a combined subtraction hybridization/differential screening approach. A cDNA was identified and sequenced which encodes a protein designated osteoblast-specific factor 2 (OSF-2) comprising 811 amino acids. OSF-2 has a typical signal sequence, followed by a cysteine-rich domain, a fourfold repeated domain and a C-terminal domain. The protein lacks a typical transmembrane region. The fourfold repeated domain of OSF-2 shows homology with the insect protein fasciclin I. RNA analyses revealed that OSF-2 is expressed in bone and to a lesser extent in lung, but not in other tissues. Mouse OSF-2 cDNA was subsequently used as a probe to clone the human counterpart. Mouse and human OSF-2 show a high amino acid sequence conservation except for the signal sequence and two regions in the C-terminal domain in which 'in-frame' insertions or deletions are observed, implying alternative splicing events. On the basis of the amino acid sequence homology with fasciclin I, we suggest that OSF-2 functions as a homophilic adhesion molecule in bone formation. Images Figure 3 Figure 4 Figure 5 Figure 6 PMID:8363580

Sequence homology and expression profile of genes associated with DNA repair pathways in Mycobacterium leprae.

PubMed

Sharma, Mukul; Vedithi, Sundeep Chaitanya; Das, Madhusmita; Roy, Anindya; Ebenezer, Mannam

2017-01-01

Survival of Mycobacterium leprae, the causative bacteria for leprosy, in the human host is dependent to an extent on the ways in which its genome integrity is retained. DNA repair mechanisms protect bacterial DNA from damage induced by various stress factors. The current study is aimed at understanding the sequence and functional annotation of DNA repair genes in M. leprae. T he genome of M. leprae was annotated using sequence alignment tools to identify DNA repair genes that have homologs in Mycobacterium tuberculosis and Escherichia coli. A set of 96 genes known to be involved in DNA repair mechanisms in E. coli and Mycobacteriaceae were chosen as a reference. Among these, 61 were identified in M. leprae based on sequence similarity and domain architecture. The 61 were classified into 36 characterized gene products (59%), 11 hypothetical proteins (18%), and 14 pseudogenes (23%). All these genes have homologs in M. tuberculosis and 49 (80.32%) in E. coli. A set of 12 genes which are absent in E. coli were present in M. leprae and in Mycobacteriaceae. These 61 genes were further investigated for their expression profiles in the whole transcriptome microarray data of M. leprae which was obtained from the signal intensities of 60bp probes, tiling the entire genome with 10bp overlaps. It was noted that transcripts corresponding to all the 61 genes were identified in the transcriptome data with varying expression levels ranging from 0.18 to 2.47 fold (normalized with 16SrRNA). The mRNA expression levels of a representative set of seven genes ( four annotated and three hypothetical protein coding genes) were analyzed using quantitative Polymerase Chain Reaction (qPCR) assays with RNA extracted from skin biopsies of 10 newly diagnosed, untreated leprosy cases. It was noted that RNA expression levels were higher for genes involved in homologous recombination whereas the genes with a low level of expression are involved in the direct repair pathway. This study provided

Genomic perspectives of spider silk genes through target capture sequencing: Conservation of stabilization mechanisms and homology-based structural models of spidroin terminal regions.

PubMed

Collin, Matthew A; Clarke, Thomas H; Ayoub, Nadia A; Hayashi, Cheryl Y

2018-07-01

A powerful system for studying protein aggregation, particularly rapid self-assembly, is spider silk. Spider silks are proteinaceous and silk proteins are synthesized and stored within silk glands as liquid dope. As needed, liquid dope is near-instantaneously transformed into solid fibers or viscous adhesives. The dominant constituents of silks are spidroins (spider fibroins) and their terminal domains are vital for the tight control of silk self-assembly. To better understand spidroin termini, we used target capture and deep sequencing to identify spidroin gene sequences from six species representing the araneoid families of Araneidae, Nephilidae, and Theridiidae. We obtained 145 terminal regions, of which 103 are newly annotated here, as well as novel variants within nine diverse spidroin types. Our comparative analyses demonstrated the conservation of acidic, basic, and cysteine amino acid residues across spidroin types that had been proposed to be important for monomer stability, dimer formation, and self-assembly from a limited sampling of spidroins. Computational, protein homology modeling revealed areas of spidroin terminal regions that are highly conserved in three-dimensions despite sequence divergence across spidroin types. Analyses of our dense sampling of terminal regions suggest that most spidroins share stabilization mechanisms, dimer formation, and tertiary structure, despite producing functionally distinct materials. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Structures of Arg- and Gln-type bacterial cysteine dioxygenase homologs: Arg- and Gln-type Bacterial CDO Homologs

DOE PAGES

Driggers, Camden M.; Hartman, Steven J.; Karplus, P. Andrew

2015-01-01

In some bacteria, cysteine is converted to cysteine sulfinic acid by cysteine dioxygenases (CDO) that are only ~15–30% identical in sequence to mammalian CDOs. Among bacterial proteins having this range of sequence similarity to mammalian CDO are some that conserve an active site Arg residue (“Arg-type” enzymes) and some having a Gln substituted for this Arg (“Gln-type” enzymes). Here, we describe a structure from each of these enzyme types by analyzing structures originally solved by structural genomics groups but not published: a Bacillus subtilis “Arg-type” enzyme that has cysteine dioxygenase activity (BsCDO), and a Ralstonia eutropha “Gln-type” CDO homolog ofmore » uncharacterized activity (ReCDOhom). The BsCDO active site is well conserved with mammalian CDO, and a cysteine complex captured in the active site confirms that the cysteine binding mode is also similar. The ReCDOhom structure reveals a new active site Arg residue that is hydrogen bonding to an iron-bound diatomic molecule we have interpreted as dioxygen. Notably, the Arg position is not compatible with the mode of Cys binding seen in both rat CDO and BsCDO. As sequence alignments show that this newly discovered active site Arg is well conserved among “Gln-type” CDO enzymes, we conclude that the “Gln-type” CDO homologs are not authentic CDOs but will have substrate specificity more similar to 3-mercaptopropionate dioxygenases.« less

CDNA encoding a polypeptide including a hevein sequence

DOEpatents

Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

1995-03-21

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

A Multidimensional Strategy to Detect Polypharmacological Targets in the Absence of Structural and Sequence Homology

PubMed Central

Durrant, Jacob D.; Amaro, Rommie E.; Xie, Lei; Urbaniak, Michael D.; Ferguson, Michael A. J.; Haapalainen, Antti; Chen, Zhijun; Di Guilmi, Anne Marie; Wunder, Frank; Bourne, Philip E.; McCammon, J. Andrew

2010-01-01

Conventional drug design embraces the “one gene, one drug, one disease” philosophy. Polypharmacology, which focuses on multi-target drugs, has emerged as a new paradigm in drug discovery. The rational design of drugs that act via polypharmacological mechanisms can produce compounds that exhibit increased therapeutic potency and against which resistance is less likely to develop. Additionally, identifying multiple protein targets is also critical for side-effect prediction. One third of potential therapeutic compounds fail in clinical trials or are later removed from the market due to unacceptable side effects often caused by off-target binding. In the current work, we introduce a multidimensional strategy for the identification of secondary targets of known small-molecule inhibitors in the absence of global structural and sequence homology with the primary target protein. To demonstrate the utility of the strategy, we identify several targets of 4,5-dihydroxy-3-(1-naphthyldiazenyl)-2,7-naphthalenedisulfonic acid, a known micromolar inhibitor of Trypanosoma brucei RNA editing ligase 1. As it is capable of identifying potential secondary targets, the strategy described here may play a useful role in future efforts to reduce drug side effects and/or to increase polypharmacology. PMID:20098496

A multidimensional strategy to detect polypharmacological targets in the absence of structural and sequence homology.

PubMed

Durrant, Jacob D; Amaro, Rommie E; Xie, Lei; Urbaniak, Michael D; Ferguson, Michael A J; Haapalainen, Antti; Chen, Zhijun; Di Guilmi, Anne Marie; Wunder, Frank; Bourne, Philip E; McCammon, J Andrew

2010-01-22

Conventional drug design embraces the "one gene, one drug, one disease" philosophy. Polypharmacology, which focuses on multi-target drugs, has emerged as a new paradigm in drug discovery. The rational design of drugs that act via polypharmacological mechanisms can produce compounds that exhibit increased therapeutic potency and against which resistance is less likely to develop. Additionally, identifying multiple protein targets is also critical for side-effect prediction. One third of potential therapeutic compounds fail in clinical trials or are later removed from the market due to unacceptable side effects often caused by off-target binding. In the current work, we introduce a multidimensional strategy for the identification of secondary targets of known small-molecule inhibitors in the absence of global structural and sequence homology with the primary target protein. To demonstrate the utility of the strategy, we identify several targets of 4,5-dihydroxy-3-(1-naphthyldiazenyl)-2,7-naphthalenedisulfonic acid, a known micromolar inhibitor of Trypanosoma brucei RNA editing ligase 1. As it is capable of identifying potential secondary targets, the strategy described here may play a useful role in future efforts to reduce drug side effects and/or to increase polypharmacology.

SGP-1: Prediction and Validation of Homologous Genes Based on Sequence Alignments

PubMed Central

Wiehe, Thomas; Gebauer-Jung, Steffi; Mitchell-Olds, Thomas; Guigó, Roderic

2001-01-01

Conventional methods of gene prediction rely on the recognition of DNA-sequence signals, the coding potential or the comparison of a genomic sequence with a cDNA, EST, or protein database. Reasons for limited accuracy in many circumstances are species-specific training and the incompleteness of reference databases. Lately, comparative genome analysis has attracted increasing attention. Several analysis tools that are based on human/mouse comparisons are already available. Here, we present a program for the prediction of protein-coding genes, termed SGP-1 (Syntenic Gene Prediction), which is based on the similarity of homologous genomic sequences. In contrast to most existing tools, the accuracy of SGP-1 depends little on species-specific properties such as codon usage or the nucleotide distribution. SGP-1 may therefore be applied to nonstandard model organisms in vertebrates as well as in plants, without the need for extensive parameter training. In addition to predicting genes in large-scale genomic sequences, the program may be useful to validate gene structure annotations from databases. To this end, SGP-1 output also contains comparisons between predicted and annotated gene structures in HTML format. The program can be accessed via a Web server at http://soft.ice.mpg.de/sgp-1. The source code, written in ANSI C, is available on request from the authors. PMID:11544202

The complete DNA sequence of lymphocystis disease virus.

PubMed

Tidona, C A; Darai, G

1997-04-14

Lymphocystis disease virus (LCDV) is the causative agent of lymphocystis disease, which has been reported to occur in over 100 different fish species worldwide. LCDV is a member of the family Iridoviridae and the type species of the genus Lymphocystivirus. The virions contain a single linear double-stranded DNA molecule, which is circularly permuted, terminally redundant, and heavily methylated at cytosines in CpG sequences. The complete nucleotide sequence of LCDV-1 (flounder isolate) was determined by automated cycle sequencing and primer walking. The genome of LCDV-1 is 102.653 bp in length and contains 195 open reading frames with coding capacities ranging from 40 to 1199 amino acids. Computer-assisted analyses of the deduced amino acid sequences led to the identification of several putative gene products with significant homologies to entries in protein data banks, such as the two major subunits of the viral DNA-dependent RNA polymerase, DNA polymerase, several protein kinases, two subunits of the ribonucleoside diphosphate reductase, DNA methyltransferase, the viral major capsid protein, insulin-like growth factor, and tumor necrosis factor receptor homolog.

Two zebrafish G2A homologs activate multiple intracellular signaling pathways in acidic environment.

PubMed

Ichijo, Yuta; Mochimaru, Yuta; Azuma, Morio; Satou, Kazuhiro; Negishi, Jun; Nakakura, Takashi; Oshima, Natsuki; Mogi, Chihiro; Sato, Koichi; Matsuda, Kouhei; Okajima, Fumikazu; Tomura, Hideaki

2016-01-01

Human G2A is activated by various stimuli such as lysophosphatidylcholine (LPC), 9-hydroxyoctadecadienoic acid (9-HODE), and protons. The receptor is coupled to multiple intracellular signaling pathways, including the Gs-protein/cAMP/CRE, G12/13-protein/Rho/SRE, and Gq-protein/phospholipase C/NFAT pathways. In the present study, we examined whether zebrafish G2A homologs (zG2A-a and zG2A-b) could respond to these stimuli and activate multiple intracellular signaling pathways. We also examined whether histidine residue and basic amino acid residue in the N-terminus of the homologs also play roles similar to those played by human G2A residues if the homologs sense protons. We found that the zG2A-a showed the high CRE, SRE, and NFAT activities, however, zG2A-b showed only the high SRE activity under a pH of 8.0. Extracellular acidification from pH 7.4 to 6.3 ameliorated these activities in zG2A-a-expressing cells. On the other hand, acidification ameliorated the SRE activity but not the CRE and NFAT activities in zG2A-b-expressing cells. LPC or 9-HODE did not modify any activity of either homolog. The substitution of histidine residue at the 174(th) position from the N-terminus of zG2A-a to asparagine residue attenuated proton-induced CRE and NFAT activities but not SRE activity. The substitution of arginine residue at the 32nd position from the N-terminus of zG2A-a to the alanine residue also attenuated its high and the proton-induced CRE and NFAT activities. On the contrary, the substitution did not attenuate SRE activity. The substitution of the arginine residue at the 10th position from the N-terminus of zG2A-b to the alanine residue also did not attenuate its high or the proton-induced SRE activity. These results indicate that zebrafish G2A homologs were activated by protons but not by LPC and 9-HODE, and the activation mechanisms of the homologs were similar to those of human G2A. Copyright © 2015 Elsevier Inc. All rights reserved.

Nucleic Acid Encoding A Lectin-Derived Progenitor Cell Preservation Factor

DOEpatents

Colucci, M. Gabriella; Chrispeels, Maarten J.; Moore, Jeffrey G.

2001-10-30

The invention relates to an isolated nucleic acid molecule that encodes a protein that is effective to preserve progenitor cells, such as hematopoietic progenitor cells. The nucleic acid comprises a sequence defined by SEQ ID NO:1, a homolog thereof, or a fragment thereof. The encoded protein has an amino acid sequence that comprises a sequence defined by SEQ ID NO:2, a homolog thereof, or a fragment thereof that contains an amino acid sequence TNNVLQVT. Methods of using the encoded protein for preserving progenitor cells in vitro, ex vivo, and in vivo are also described. The invention, therefore, include methods such as myeloablation therapies for cancer treatment wherein myeloid reconstitution is facilitated by means of the specified protein. Other therapeutic utilities are also enabled through the invention, for example, expanding progenitor cell populations ex vivo to increase chances of engraftation, improving conditions for transporting and storing progenitor cells, and facilitating gene therapy to treat and cure a broad range of life-threatening hematologic diseases.

Construction and production of oncotropic vectors, derived from MVM(p), that share reduced sequence homology with helper plasmids.

PubMed

Clément, Nathalie; Velu, Thierry; Brandenburger, Annick

2002-09-01

The production of currently available vectors derived from autonomous parvoviruses requires the expression of capsid proteins in trans, from helper sequences. Cotransfection of a helper plasmid always generates significant amounts of replication-competent virus (RCV) that can be reduced by the integration of helper sequences into a packaging cell line. Although stocks of minute virus of mice (MVM)-based vectors with no detectable RCV could be produced by transfection into packaging cells; the latter appear after one or two rounds of replication, precluding further amplification of the vector stock. Indeed, once RCVs become detectable, they are efficiently amplified and rapidly take over the culture. Theoretically RCV-free vector stocks could be produced if all homology between vector and helper DNA is eliminated, thus preventing homologous recombination. We constructed new vectors based on the structure of spontaneously occurring defective particles of MVM. Based on published observations related to the size of vectors and the sequence of the viral origin of replication, these vectors were modified by the insertion of foreign DNA sequences downstream of the transgene and by the introduction of a consensus NS-1 nick site near the origin of replication to optimize their production. In one of the vectors the inserted fragment of mouse genomic DNA had a synergistic effect with the modified origin of replication in increasing vector production.

cDNA encoding a polypeptide including a hevein sequence

DOEpatents

Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

1999-05-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

cDNA encoding a polypeptide including a hevein sequence

DOEpatents

Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

1999-05-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 12 figs.

cDNA encoding a polypeptide including a hevein sequence

DOEpatents

Raikhel, N.V.; Broekaert, W.F.; Chua, N.H.; Kush, A.

1995-03-21

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1,018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74--79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli. 11 figures.

Lactobacillus kefiri shows inter-strain variations in the amino acid sequence of the S-layer proteins.

PubMed

Malamud, Mariano; Carasi, Paula; Bronsoms, Sílvia; Trejo, Sebastián A; Serradell, María de Los Angeles

2017-04-01

The S-layer is a proteinaceous envelope constituted by subunits that self-assemble to form a two-dimensional lattice that covers the surface of different species of Bacteria and Archaea, and it could be involved in cell recognition of microbes among other several distinct functions. In this work, both proteomic and genomic approaches were used to gain knowledge about the sequences of the S-layer protein (SLPs) encoding genes expressed by six aggregative and sixteen non-aggregative strains of potentially probiotic Lactobacillus kefiri. Peptide mass fingerprint (PMF) analysis confirmed the identity of SLPs extracted from L. kefiri, and based on the homology with phylogenetically related species, primers located outside and inside the SLP-genes were employed to amplify genomic DNA. The O-glycosylation site SASSAS was found in all L. kefiri SLPs. Ten strains were selected for sequencing of the complete genes. The total length of the mature proteins varies from 492 to 576 amino acids, and all SLPs have a calculated pI between 9.37 and 9.60. The N-terminal region is relatively conserved and shows a high percentage of positively charged amino acids. Major differences among strains are found in the C-terminal region. Different groups could be distinguished regarding the mature SLPs and the similarities observed in the PMF spectra. Interestingly, SLPs of the aggregative strains are 100% homologous, although these strains were isolated from different kefir grains. This knowledge provides relevant data for better understanding of the mechanisms involved in SLPs functionality and could contribute to the development of products of biotechnological interest from potentially probiotic bacteria.

Chimeric mitochondrial minichromosomes of the human body louse, Pediculus humanus: evidence for homologous and non-homologous recombination.

PubMed

Shao, Renfu; Barker, Stephen C

2011-02-15

The mitochondrial (mt) genome of the human body louse, Pediculus humanus, consists of 18 minichromosomes. Each minichromosome is 3 to 4 kb long and has 1 to 3 genes. There is unequivocal evidence for recombination between different mt minichromosomes in P. humanus. It is not known, however, how these minichromosomes recombine. Here, we report the discovery of eight chimeric mt minichromosomes in P. humanus. We classify these chimeric mt minichromosomes into two groups: Group I and Group II. Group I chimeric minichromosomes contain parts of two different protein-coding genes that are from different minichromosomes. The two parts of protein-coding genes in each Group I chimeric minichromosome are joined at a microhomologous nucleotide sequence; microhomologous nucleotide sequences are hallmarks of non-homologous recombination. Group II chimeric minichromosomes contain all of the genes and the non-coding regions of two different minichromosomes. The conserved sequence blocks in the non-coding regions of Group II chimeric minichromosomes resemble the "recombination repeats" in the non-coding regions of the mt genomes of higher plants. These repeats are essential to homologous recombination in higher plants. Our analyses of the nucleotide sequences of chimeric mt minichromosomes indicate both homologous and non-homologous recombination between minichromosomes in the mitochondria of the human body louse. Copyright © 2010 Elsevier B.V. All rights reserved.

Identification and chromosomal localization of Atm, the mouse homolog of the ataxia-telangiectasia gene.

PubMed

Pecker, I; Avraham, K B; Gilbert, D J; Savitsky, K; Rotman, G; Harnik, R; Fukao, T; Schröck, E; Hirotsune, S; Tagle, D A; Collins, F S; Wynshaw-Boris, A; Ried, T; Copeland, N G; Jenkins, N A; Shiloh, Y; Ziv, Y

1996-07-01

Atm, the mouse homolog of the human ATM gene defective in ataxia-telangiectasia (A-T), has been identified. The entire coding sequence of the Atm transcript was cloned and found to contain an open reading frame encoding a protein of 3066 amino acids with 84% overall identity and 91% similarity to the human ATM protein. Variable levels of expression of Atm were observed in different tissues. Fluorescence in situ hybridization and linkage analysis located the Atm gene on mouse chromosome 9, band 9C, in a region homologous to the ATM region on human chromosome 11q22-q23.

Detection of nucleic acid sequences by invader-directed cleavage

DOEpatents

Brow, Mary Ann D.; Hall, Jeff Steven Grotelueschen; Lyamichev, Victor; Olive, David Michael; Prudent, James Robert

1999-01-01

The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The 5' nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based by charge.

The mitochondnal genome of Aspergillus nidulans contains reading frames homologous to the human URFs 1 and 4.

PubMed Central

Brown, T A; Davies, R W; Ray, J A; Waring, R B; Scazzocchio, C

1983-01-01

A 2830-bp segment of the mitochondrial genome of the fungus Aspergillus nidulans was sequenced and shown to contain two unidentified reading frames (URFs). These reading frames are 352 and 488 codons in length, and would specify unmodified proteins of mol. wts. 39,000 and 54,000, respectively. The derived amino acid sequences indicate that these genes are equivalent to the human mitochondrial URFs 1 and 4, with 39% amino acid homology for URF1 and 26% for URF4. Both URFs were shown by secondary structure predictions to code for predominantly beta-sheeted proteins with strong structural conservation between the fungal and human homologues. Counterparts of mammalian URFs have not previously been identified in non-mammalian genomes, and the discovery that A. nidulans possesses reading frames so closely homologous with URF1 and URF4 shows that these genes are of general functional importance in the mitochondria of diverse species. PMID:11894959

Amino acid and nucleotide recurrence in aligned sequences: synonymous substitution patterns in association with global and local base compositions.

PubMed

Nishizawa, M; Nishizawa, K

2000-10-01

The tendency for repetitiveness of nucleotides in DNA sequences has been reported for a variety of organisms. We show that the tendency for repetitive use of amino acids is widespread and is observed even for segments conserved between human and Drosophila melanogaster at the level of >50% amino acid identity. This indicates that repetitiveness influences not only the weakly constrained segments but also those sequence segments conserved among phyla. Not only glutamine (Q) but also many of the 20 amino acids show a comparable level of repetitiveness. Repetitiveness in bases at codon position 3 is stronger for human than for D.melanogaster, whereas local repetitiveness in intron sequences is similar between the two organisms. While genes for immune system-specific proteins, but not ancient human genes (i.e. human homologs of Escherichia coli genes), have repetitiveness at codon bases 1 and 2, repetitiveness at codon base 3 for these groups is similar, suggesting that the human genome has at least two mechanisms generating local repetitiveness. Neither amino acid nor nucleotide repetitiveness is observed beyond the exon boundary, denying the possibility that such repetitiveness could mainly stem from natural selection on mRNA or protein sequences. Analyses of mammalian sequence alignments show that while the 'between gene' GC content heterogeneity, which is linked to 'isochores', is a principal factor associated with the bias in substitution patterns in human, 'within gene' heterogeneity in nucleotide composition is also associated with such bias on a more local scale. The relationship amongst the various types of repetitiveness is discussed.

Amino acid and nucleotide recurrence in aligned sequences: synonymous substitution patterns in association with global and local base compositions

PubMed Central

Nishizawa, Manami; Nishizawa, Kazuhisa

2000-01-01

The tendency for repetitiveness of nucleotides in DNA sequences has been reported for a variety of organisms. We show that the tendency for repetitive use of amino acids is widespread and is observed even for segments conserved between human and Drosophila melanogaster at the level of >50% amino acid identity. This indicates that repetitiveness influences not only the weakly constrained segments but also those sequence segments conserved among phyla. Not only glutamine (Q) but also many of the 20 amino acids show a comparable level of repetitiveness. Repetitiveness in bases at codon position 3 is stronger for human than for D.melanogaster, whereas local repetitiveness in intron sequences is similar between the two organisms. While genes for immune system-specific proteins, but not ancient human genes (i.e. human homologs of Escherichia coli genes), have repetitiveness at codon bases 1 and 2, repetitiveness at codon base 3 for these groups is similar, suggesting that the human genome has at least two mechanisms generating local repetitiveness. Neither amino acid nor nucleotide repetitiveness is observed beyond the exon boundary, denying the possibility that such repetitiveness could mainly stem from natural selection on mRNA or protein sequences. Analyses of mammalian sequence alignments show that while the ‘between gene’ GC content heterogeneity, which is linked to ‘isochores’, is a principal factor associated with the bias in substitution patterns in human, ‘within gene’ heterogeneity in nucleotide composition is also associated with such bias on a more local scale. The relationship amongst the various types of repetitiveness is discussed. PMID:11000273

Amino acid sequence of bovine muzzle epithelial desmocollin derived from cloned cDNA: a novel subtype of desmosomal cadherins.

PubMed

Koch, P J; Goldschmidt, M D; Walsh, M J; Zimbelmann, R; Schmelz, M; Franke, W W

1991-05-01

Desmosomes are cell-type-specific intercellular junctions found in epithelium, myocardium and certain other tissues. They consist of assemblies of molecules involved in the adhesion of specific cell types and in the anchorage of cell-type-specific cytoskeletal elements, the intermediate-size filaments, to the plasma membrane. To explore the individual desmosomal components and their functions we have isolated DNA clones encoding the desmosomal glycoprotein, desmocollin, using antibodies and a cDNA expression library from bovine muzzle epithelium. The cDNA-deduced amino-acid sequence of desmocollin (presently we cannot decide to which of the two desmocollins, DC I or DC II, this clone relates) defines a polypeptide with a calculated molecular weight of 85,000, with a single candidate sequence of 24 amino acids sufficiently long for a transmembrane arrangement, and an extracellular aminoterminal portion of 561 amino acid residues, compared to a cytoplasmic part of only 176 amino acids. Amino acid sequence comparisons have revealed that desmocollin is highly homologous to members of the cadherin family of cell adhesion molecules, including the previously sequenced desmoglein, another desmosome-specific cadherin. Using riboprobes derived from cDNAs for Northern-blot analyses, we have identified an mRNA of approximately 6 kb in stratified epithelia such as muzzle epithelium and tongue mucosa but not in two epithelial cell culture lines containing desmosomes and desmoplakins. The difference may indicate drastic differences in mRNA concentration or the existence of cell-type-specific desmocollin subforms. The molecular topology of desmocollin(s) is discussed in relation to possible functions of the individual molecular domains.

Methods and compositions for efficient nucleic acid sequencing

DOEpatents

Drmanac, Radoje

2006-07-04

Disclosed are novel methods and compositions for rapid and highly efficient nucleic acid sequencing based upon hybridization with two sets of small oligonucleotide probes of known sequences. Extremely large nucleic acid molecules, including chromosomes and non-amplified RNA, may be sequenced without prior cloning or subcloning steps. The methods of the invention also solve various current problems associated with sequencing technology such as, for example, high noise to signal ratios and difficult discrimination, attaching many nucleic acid fragments to a surface, preparing many, longer or more complex probes and labelling more species.

Methods and compositions for efficient nucleic acid sequencing

DOEpatents

Drmanac, Radoje

2002-01-01

Disclosed are novel methods and compositions for rapid and highly efficient nucleic acid sequencing based upon hybridization with two sets of small oligonucleotide probes of known sequences. Extremely large nucleic acid molecules, including chromosomes and non-amplified RNA, may be sequenced without prior cloning or subcloning steps. The methods of the invention also solve various current problems associated with sequencing technology such as, for example, high noise to signal ratios and difficult discrimination, attaching many nucleic acid fragments to a surface, preparing many, longer or more complex probes and labelling more species.

Pseudomonas aeruginosa Type III Secretory Toxin ExoU and Its Predicted Homologs.

PubMed

Sawa, Teiji; Hamaoka, Saeko; Kinoshita, Mao; Kainuma, Atsushi; Naito, Yoshifumi; Akiyama, Koichi; Kato, Hideya

2016-10-26

Pseudomonas aeruginosa ExoU, a type III secretory toxin and major virulence factor with patatin-like phospholipase activity, is responsible for acute lung injury and sepsis in immunocompromised patients. Through use of a recently updated bacterial genome database, protein sequences predicted to be homologous to Ps. aeruginosa ExoU were identified in 17 other Pseudomonas species ( Ps. fluorescens , Ps. lundensis , Ps. weihenstephanensis , Ps. marginalis, Ps. rhodesiae, Ps. synxantha , Ps. libanensis , Ps. extremaustralis , Ps. veronii , Ps. simiae , Ps. trivialis , Ps. tolaasii , Ps. orientalis , Ps. taetrolens , Ps. syringae , Ps. viridiflava , and Ps. cannabina ) and 8 Gram-negative bacteria from three other genera ( Photorhabdus , Aeromonas , and Paludibacterium ). In the alignment of the predicted primary amino acid sequences used for the phylogenetic analyses, both highly conserved and nonconserved parts of the toxin were discovered among the various species. Further comparative studies of the predicted ExoU homologs should provide us with more detailed information about the unique characteristics of the Ps. aeruginosa ExoU toxin.

cDNA encoding a polypeptide including a hev ein sequence

DOEpatents

Raikhel, Natasha V.; Broekaert, Willem F.; Chua, Nam-Hai; Kush, Anil

2000-07-04

A cDNA clone (HEV1) encoding hevein was isolated via polymerase chain reaction (PCR) using mixed oligonucleotides corresponding to two regions of hevein as primers and a Hevea brasiliensis latex cDNA library as a template. HEV1 is 1018 nucleotides long and includes an open reading frame of 204 amino acids. The deduced amino acid sequence contains a putative signal sequence of 17 amino acid residues followed by a 187 amino acid polypeptide. The amino-terminal region (43 amino acids) is identical to hevein and shows homology to several chitin-binding proteins and to the amino-termini of wound-induced genes in potato and poplar. The carboxyl-terminal portion of the polypeptide (144 amino acids) is 74-79% homologous to the carboxyl-terminal region of wound-inducible genes of potato. Wounding, as well as application of the plant hormones abscisic acid and ethylene, resulted in accumulation of hevein transcripts in leaves, stems and latex, but not in roots, as shown by using the cDNA as a probe. A fusion protein was produced in E. coli from the protein of the present invention and maltose binding protein produced by the E. coli.

Purification, characterization, gene cloning and nucleotide sequencing of D: -stereospecific amino acid amidase from soil bacterium: Delftia acidovorans.

PubMed

Hongpattarakere, Tipparat; Komeda, Hidenobu; Asano, Yasuhisa

2005-12-01

The D-amino acid amidase-producing bacterium was isolated from soil samples using an enrichment culture technique in medium broth containing D-phenylalanine amide as a sole source of nitrogen. The strain exhibiting the strongest activity was identified as Delftia acidovorans strain 16. This strain produced intracellular D-amino acid amidase constitutively. The enzyme was purified about 380-fold to homogeneity and its molecular mass was estimated to be about 50 kDa, on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme was active preferentially toward D-amino acid amides rather than their L-counterparts. It exhibited strong amino acid amidase activity toward aromatic amino acid amides including D-phenylalanine amide, D-tryptophan amide and D-tyrosine amide, yet it was not specifically active toward low-molecular-weight D-amino acid amides such as D-alanine amide, L-alanine amide and L-serine amide. Moreover, it was not specifically active toward oligopeptides. The enzyme showed maximum activity at 40 degrees C and pH 8.5 and appeared to be very stable, with 92.5% remaining activity after the reaction was performed at 45 degrees C for 30 min. However, it was mostly inactivated in the presence of phenylmethanesulfonyl fluoride or Cd2+, Ag+, Zn2+, Hg2+ and As3+ . The NH2 terminal and internal amino acid sequences of the enzyme were determined; and the gene was cloned and sequenced. The enzyme gene damA encodes a 466-amino-acid protein (molecular mass 49,860.46 Da); and the deduced amino acid sequence exhibits homology to the D-amino acid amidase from Variovorax paradoxus (67.9% identity), the amidotransferase A subunit from Burkholderia fungorum (50% identity) and other enantioselective amidases.

DR-78, a novel Drosophila melanogaster genomic DNA fragment highly homologous to the DNA-binding domain of thyroid hormone-retinoic acid-vitamin D receptor subfamily.

PubMed

Martín-Blanco, E; Kornberg, T B

1993-11-16

Degenerate oligodeoxyribonucleotides were designed for both ends of the DNA-binding domain of members of the nuclear receptor superfamily. PCR amplified Drosophila melanogaster DNA was purified and cloned (DR plasmids). Genomic lambda DASH clones were identified at high stringency with an amplified DR-78 plasmid DNA and isolated. The partial sequence shows a very probable open reading frame which would encode a peptide highly homologous to members of the thyroid hormone-retinoic acid-vitamin D receptor subfamily. The fragment corresponds to a single copy gene and was mapped at position 78D of chromosome three by in situ hybridization.

Molecular characterization of DnaJ 5 homologs in silkworm Bombyx mori and its expression during egg diapause.

PubMed

Sirigineedi, Sasibhushan; Vijayagowri, Esvaran; Murthy, Geetha N; Rao, Guruprasada; Ponnuvel, Kangayam M

2014-12-01

A comparison of the cDNA sequences (1 056 bp) of Bombyx mori DnaJ 5 homolog with B. mori genome revealed that unlike in other Hsps, it has an intron of 234 bp. The DnaJ 5 homolog contains 351 amino acids, of which 70 contain the conserved DnaJ domain at the N-terminal end. This homolog of B. mori has all desirable functional domains similar to other insects, and the 13 different DnaJ homologs identified in B. mori genome were distributed on different chromosomes. The expressed sequence tag database analysis of Hsp40 gene expression revealed higher expression in wing disc followed by diapause-induced eggs. Microarray analysis revealed higher expression of DnaJ 5 homolog at 18th h after oviposition in diapause-induced eggs. Further validation of DnaJ 5 expression through qPCR in diapause-induced and nondiapause eggs at different time intervals revealed higher expression in diapause eggs at 18 and 24 h after oviposition, which coincided with the expression of Hsp70 as the Hsp 40 is its co-chaperone. This study thus provides an outline of the genome organization of Hsp40 gene, and its role in egg diapause induction in B. mori. © 2013 Institute of Zoology, Chinese Academy of Sciences.

A Symplectic Instanton Homology via Traceless Character Varieties

NASA Astrophysics Data System (ADS)

Horton, Henry T.

Since its inception, Floer homology has been an important tool in low-dimensional topology. Floer theoretic invariants of 3-manifolds tend to be either gauge theoretic or symplecto-geometric in nature, and there is a general philosophy that each gauge theoretic Floer homology should have a corresponding symplectic Floer homology and vice-versa. In this thesis, we construct a Lagrangian Floer invariant for any closed, oriented 3-manifold Y (called the symplectic instanton homology of Y and denoted SI(Y)) which is conjecturally equivalent to a Floer homology defined using a certain variant of Yang-Mills gauge theory. The crucial ingredient for defining SI( Y) is the use of traceless character varieties in the symplectic setting, which allow us to avoid the debilitating technical hurdles present when one attempts to define a symplectic version of instanton Floer homologies. Floer theories are also expected to roughly satisfy the axioms of a topological quantum field theory (TQFT), and furthermore Dehn surgeries on knots should induce exact triangles of Floer homologies. Following a strategy used by Ozsvath and Szabo in the context of Heegaard Floer homology, we prove that our theory is functorial with respect to connected 4-dimensional cobordisms, so that cobordisms induce homomorphisms between symplectic instanton homologies. By studying the effect of Dehn surgeries on traceless character varieties, we establish a surgery exact triangle using work of Seidel that relates the geometry of Lefschetz fibrations with exact triangles in Lagrangian Floer theory. We further prove that Dehn surgeries on a link L in a 3-manifold Y induce a spectral sequence of symplectic instanton homologies - the E2-page is isomorphic to a direct sum of symplectic instanton homologies of all possible combinations of 0- and 1-surgeries on the components of L, and the spectral sequence converges to SI(Y). For the branched double cover Sigma(L) of a link L in S3, we show there is a link surgery

Advances in Homology Protein Structure Modeling

PubMed Central

Xiang, Zhexin

2007-01-01

Homology modeling plays a central role in determining protein structure in the structural genomics project. The importance of homology modeling has been steadily increasing because of the large gap that exists between the overwhelming number of available protein sequences and experimentally solved protein structures, and also, more importantly, because of the increasing reliability and accuracy of the method. In fact, a protein sequence with over 30% identity to a known structure can often be predicted with an accuracy equivalent to a low-resolution X-ray structure. The recent advances in homology modeling, especially in detecting distant homologues, aligning sequences with template structures, modeling of loops and side chains, as well as detecting errors in a model, have contributed to reliable prediction of protein structure, which was not possible even several years ago. The ongoing efforts in solving protein structures, which can be time-consuming and often difficult, will continue to spur the development of a host of new computational methods that can fill in the gap and further contribute to understanding the relationship between protein structure and function. PMID:16787261

Novel homologous lactate transporter improves L-lactic acid production from glycerol in recombinant strains of Pichia pastoris.

PubMed

de Lima, Pollyne Borborema Almeida; Mulder, Kelly Cristina Leite; Melo, Nadiele Tamires Moreira; Carvalho, Lucas Silva; Menino, Gisele Soares; Mulinari, Eduardo; de Castro, Virgilio H; Dos Reis, Thaila F; Goldman, Gustavo Henrique; Magalhães, Beatriz Simas; Parachin, Nádia Skorupa

2016-09-15

Crude glycerol is the main byproduct of the biodiesel industry. Although it can have different applications, its purification is costly. Therefore, in this study a biotechnological route has been proposed for further utilization of crude glycerol in the fermentative production of lactic acid. This acid is largely utilized in food, pharmaceutical, textile, and chemical industries, making it the hydroxycarboxylic acid with the highest market potential worldwide. Currently, industrial production of lactic acid is done mainly using sugar as the substrate. Thus here, for the first time, Pichia pastoris has been engineered for heterologous L-lactic acid production using glycerol as a single carbon source. For that, the Bos taurus lactate dehydrogenase gene was introduced into P. pastoris. Moreover, a heterologous and a novel homologous lactate transporter have been evaluated for L-lactic acid production. Batch fermentation of the P. pastoris X-33 strain producing LDHb allowed for lactic acid production in this yeast. Although P. pastoris is known for its respiratory metabolism, batch fermentations were performed with different oxygenation levels, indicating that lower oxygen availability increased lactic acid production by 20 %, pushing the yeast towards a fermentative metabolism. Furthermore, a newly putative lactate transporter from P. pastoris named PAS has been identified by search similarity with the lactate transporter from Saccharomyces cerevisiae Jen1p. Both heterologous and homologous transporters, Jen1p and PAS, were evaluated in one strain already containing LDH activity. Fed-batch experiments of P. pastoris strains carrying the lactate transporter were performed with the batch phase at aerobic conditions followed by an aerobic oxygen-limited phase where production of lactic acid was favored. The results showed that the strain containing PAS presented the highest lactic acid titer, reaching a yield of approximately 0.7 g/g. We showed that P. pastoris has a

Cloning and characterization of WRKY gene homologs in Chieh-qua (Benincasa hispida Cogn. var. Chieh-qua How) and their expression in response to fusaric acid treatment.

PubMed

Mao, Yizhou; Jiang, Biao; Peng, Qingwu; Liu, Wenrui; Lin, Yue; Xie, Dasen; He, Xiaoming; Li, Shaoshan

2017-05-01

The WRKY transcription factors play an important role in plant resistance for biotic and abiotic stresses. In the present study, we cloned 10 WRKY gene homologs (CqWRKY) in Chieh-qua (Benincasa hispida Cogn. var. Chieh-qua) using the rapid-amplification of cDNA ends (RACE) or homology-based cloning methods. We characterized the structure of these CqWRKY genes. Phylogenetic analysis of these sequences with cucumber homologs suggested possible structural conservation of these genes among cucurbit crops. We examined the expression levels of these genes in response to fusaric acid (FA) treatment between resistant and susceptible Chieh-qua lines with quantitative real-time PCR. All genes could be upregulated upon FA treatment, but four CqWRKY genes exhibited differential expression between resistant and susceptible lines before and after FA application. CqWRKY31 seemed to be a positive regulator while CqWRKY1, CqWRKY23 and CqWRKY53 were negative regulators of fusaric resistance. This is the first report of characterization of WRKY family genes in Chieh-qua. The results may also be useful in breeding Chieh-qua for Fusarium wilt resistance.

Homology and phylogeny and their automated inference

NASA Astrophysics Data System (ADS)

Fuellen, Georg

2008-06-01

The analysis of the ever-increasing amount of biological and biomedical data can be pushed forward by comparing the data within and among species. For example, an integrative analysis of data from the genome sequencing projects for various species traces the evolution of the genomes and identifies conserved and innovative parts. Here, I review the foundations and advantages of this “historical” approach and evaluate recent attempts at automating such analyses. Biological data is comparable if a common origin exists (homology), as is the case for members of a gene family originating via duplication of an ancestral gene. If the family has relatives in other species, we can assume that the ancestral gene was present in the ancestral species from which all the other species evolved. In particular, describing the relationships among the duplicated biological sequences found in the various species is often possible by a phylogeny, which is more informative than homology statements. Detecting and elaborating on common origins may answer how certain biological sequences developed, and predict what sequences are in a particular species and what their function is. Such knowledge transfer from sequences in one species to the homologous sequences of the other is based on the principle of ‘my closest relative looks and behaves like I do’, often referred to as ‘guilt by association’. To enable knowledge transfer on a large scale, several automated ‘phylogenomics pipelines’ have been developed in recent years, and seven of these will be described and compared. Overall, the examples in this review demonstrate that homology and phylogeny analyses, done on a large (and automated) scale, can give insights into function in biology and biomedicine.

Dipeptide Sequence Determination: Analyzing Phenylthiohydantoin Amino Acids by HPLC

NASA Astrophysics Data System (ADS)

Barton, Janice S.; Tang, Chung-Fei; Reed, Steven S.

2000-02-01

Amino acid composition and sequence determination, important techniques for characterizing peptides and proteins, are essential for predicting conformation and studying sequence alignment. This experiment presents improved, fundamental methods of sequence analysis for an upper-division biochemistry laboratory. Working in pairs, students use the Edman reagent to prepare phenylthiohydantoin derivatives of amino acids for determination of the sequence of an unknown dipeptide. With a single HPLC technique, students identify both the N-terminal amino acid and the composition of the dipeptide. This method yields good precision of retention times and allows use of a broad range of amino acids as components of the dipeptide. Students learn fundamental principles and techniques of sequence analysis and HPLC.

Allergenic characterization of a novel allergen, homologous to chymotrypsin, from german cockroach.

PubMed

Jeong, Kyoung Yong; Son, Mina; Lee, Jae Hyun; Hong, Chein Soo; Park, Jung Won

2015-05-01

Cockroach feces are known to be rich in IgE-reactive components. Various protease allergens were identified by proteomic analysis of German cockroach fecal extract in a previous study. In this study, we characterized a novel allergen, a chymotrypsin-like serine protease. A cDNA sequence homologous to chymotrypsin was obtained by analysis of German cockroach expressed sequence tag (EST) clones. The recombinant chymotrypsins from the German cockroach and house dust mite (Der f 6) were expressed in Escherichia coli using the pEXP5NT/TOPO vector system, and their allergenicity was investigated by ELISA. The deduced amino acid sequence of German cockroach chymotrypsin showed 32.7 to 43.1% identity with mite group 3 (trypsin) and group 6 (chymotrypsin) allergens. Sera from 8 of 28 German cockroach allergy subjects (28.6%) showed IgE binding to the recombinant protein. IgE binding to the recombinant cockroach chymotrypsin was inhibited by house dust mite chymotrypsin Der f 6, while it minimally inhibited the German cockroach whole body extract. A novel allergen homologous to chymotrypsin was identified from the German cockroach and was cross-reactive with Der f 6.

Nucleotide and deduced amino acid sequence of the envelope gene of the Vasilchenko strain of TBE virus; comparison with other flaviviruses.

PubMed

Gritsun, T S; Frolova, T V; Pogodina, V V; Lashkevich, V A; Venugopal, K; Gould, E A

1993-02-01

A strain of tick-borne encephalitis virus known as Vasilchenko (Vs) exhibits relatively low virulence characteristics in monkeys, Syrian hamsters and humans. The gene encoding the envelope glycoprotein of this virus was cloned and sequenced. Alignment of the sequence with those of other known tick-borne flaviviruses and identification of the recognised amino acid genetic marker EHLPTA confirmed its identity as a member of the TBE complex. However, Vs virus was distinguishable from eastern and western tick-borne serotypes by the presence of the sequence AQQ at amino acid positions 232-234 and also by the presence of other specific amino acid substitutions which may be genetic markers for these viruses and could determine their pathogenetic characteristics. When compared with other tick-borne flaviviruses, Vs virus had 12 unique amino acid substitutions including an additional potential glycosylation site at position (315-317). The Vs virus strain shared closest nucleotide and amino acid homology (84.5% and 95.5% respectively) with western and far eastern strains of tick-borne encephalitis virus. Comparison with the far eastern serotype of tick-borne encephalitis virus, by cross-immunoelectrophoresis of Vs virions and PAGE analysis of the extracted virion proteins, revealed differences in surface charge and virus stability that may account for the different virulence characteristics of Vs virus. These results support and enlarge upon previous data obtained from molecular and serological analysis.

Cloning and characterization of the Drosophila homolog of the xeroderma pigmentosum complementation-group B correcting gene, ERCC3.

PubMed Central

Koken, M H; Vreeken, C; Bol, S A; Cheng, N C; Jaspers-Dekker, I; Hoeijmakers, J H; Eeken, J C; Weeda, G; Pastink, A

1992-01-01

Previously the human nucleotide excision repair gene ERCC3 was shown to be responsible for a rare combination of the autosomal recessive DNA repair disorders xeroderma pigmentosum (complementation group B) and Cockayne's syndrome (complementation group C). The human and mouse ERCC3 proteins contain several sequence motifs suggesting that it is a nucleic acid or chromatin binding helicase. To study the significance of these domains and the overall evolutionary conservation of the gene, the homolog from Drosophila melanogaster was isolated by low stringency hybridizations using two flanking probes of the human ERCC3 cDNA. The flanking probe strategy selects for long stretches of nucleotide sequence homology, and avoids isolation of small regions with fortuitous homology. In situ hybridization localized the gene onto chromosome III 67E3/4, a region devoid of known D.melanogaster mutagen sensitive mutants. Northern blot analysis showed that the gene is continuously expressed in all stages of fly development. A slight increase (2-3 times) of ERCC3Dm transcript was observed in the later stages. Two almost full length cDNAs were isolated, which have different 5' untranslated regions (UTR). The SD4 cDNA harbours only one long open reading frame (ORF) coding for ERCC3Dm. Another clone (SD2), however, has the potential to encode two proteins: a 170 amino acids polypeptide starting at the optimal first ATG has no detectable homology with any other proteins currently in the data bases, and another ORF beginning at the suboptimal second startcodon which is identical to that of SD4. Comparison of the encoded ERCC3Dm protein with the homologous proteins of mouse and man shows a strong amino acid conservation (71% identity), especially in the postulated DNA binding region and seven 'helicase' domains. The ERCC3Dm sequence is fully consistent with the presumed functions and the high conservation of these regions strengthens their functional significance. Microinjection and DNA

Expression of an Atriplex nummularia gene encoding a protein homologous to the bacterial molecular chaperone DnaJ.

PubMed Central

Zhu, J K; Shi, J; Bressan, R A; Hasegawa, P M

1993-01-01

DnaJ is a 36-kD heat shock protein that functions together with Dnak (Hsp70) as a molecular chaperone in Escherichia coli. We have obtained a cDNA clone from the higher plant Atriplex nummularia that encodes a 46.6-kD polypeptide (ANJ1) with an overall 35.2% amino acid sequence identity with the E. coli DnaJ. ANJ1 has 43.4% overall sequence identity with the Saccharomyces cerevisiae cytoplasmic DnaJ homolog YDJ1/MAS5. Complementation of the yeast mas5 mutation indicated that ANJ1 is a functional homolog of YDJ1/MAS5. The presence of other DnaJ homologs in A. nummularia was demonstrated by the detection of proteins that are antigenically related to the yeast mitochondrial DnaJ homolog SCJ1 and the yeast DnaJ-related protein Sec63. Expression of the ANJ1 gene was compared with that of an A. nummularia Hsp70 gene. Expression of both ANJ1 and Hsp70 transcripts was coordinately induced by heat shock. However, noncoordinate accumulation of ANJ1 and Hsp70 mRNAs occurred during the cell growth cycle and in response to NaCl stress. PMID:8467224

Expression of an Atriplex nummularia gene encoding a protein homologous to the bacterial molecular chaperone DnaJ.

PubMed

Zhu, J K; Shi, J; Bressan, R A; Hasegawa, P M

1993-03-01

DnaJ is a 36-kD heat shock protein that functions together with Dnak (Hsp70) as a molecular chaperone in Escherichia coli. We have obtained a cDNA clone from the higher plant Atriplex nummularia that encodes a 46.6-kD polypeptide (ANJ1) with an overall 35.2% amino acid sequence identity with the E. coli DnaJ. ANJ1 has 43.4% overall sequence identity with the Saccharomyces cerevisiae cytoplasmic DnaJ homolog YDJ1/MAS5. Complementation of the yeast mas5 mutation indicated that ANJ1 is a functional homolog of YDJ1/MAS5. The presence of other DnaJ homologs in A. nummularia was demonstrated by the detection of proteins that are antigenically related to the yeast mitochondrial DnaJ homolog SCJ1 and the yeast DnaJ-related protein Sec63. Expression of the ANJ1 gene was compared with that of an A. nummularia Hsp70 gene. Expression of both ANJ1 and Hsp70 transcripts was coordinately induced by heat shock. However, noncoordinate accumulation of ANJ1 and Hsp70 mRNAs occurred during the cell growth cycle and in response to NaCl stress.

77 FR 65537 - Requirements for Patent Applications Containing Nucleotide Sequence and/or Amino Acid Sequence...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-29

... DEPARTMENT OF COMMERCE Patent and Trademark Office Requirements for Patent Applications Containing Nucleotide Sequence and/or Amino Acid Sequence Disclosures ACTION: Proposed collection; comment request... Patent applications that contain nucleotide and/or amino acid sequence disclosures must include a copy of...

High speed nucleic acid sequencing

DOEpatents

Korlach, Jonas [Ithaca, NY; Webb, Watt W [Ithaca, NY; Levene, Michael [Ithaca, NY; Turner, Stephen [Ithaca, NY; Craighead, Harold G [Ithaca, NY; Foquet, Mathieu [Ithaca, NY

2011-05-17

The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid. Each type of labeled nucleotide comprises an acceptor fluorophore attached to a phosphate portion of the nucleotide such that the fluorophore is removed upon incorporation into a growing strand. Fluorescent signal is emitted via fluorescent resonance energy transfer between the donor fluorophore and the acceptor fluorophore as each nucleotide is incorporated into the growing strand. The sequence is deduced by identifying which base is being incorporated into the growing strand.

Identification of SHIP-1 and SHIP-2 homologs in channel catfish, Ictalurus punctatus

USDA-ARS?s Scientific Manuscript database

Src homology domain 2 (SH2) domain-containing inositol 5’-phosphatases (SHIP) proteins have diverse roles in signal transduction. SHIP-1 and SHIP-2 homologs were identified in channel catfish, Ictalurus punctatus, based on sequence homology to murine and human SHIP sequences. Full-length cDNAs for ...

Metagenomic gene annotation by a homology-independent approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Froula, Jeff; Zhang, Tao; Salmeen, Annette

2011-06-02

Fully understanding the genetic potential of a microbial community requires functional annotation of all the genes it encodes. The recently developed deep metagenome sequencing approach has enabled rapid identification of millions of genes from a complex microbial community without cultivation. Current homology-based gene annotation fails to detect distantly-related or structural homologs. Furthermore, homology searches with millions of genes are very computational intensive. To overcome these limitations, we developed rhModeller, a homology-independent software pipeline to efficiently annotate genes from metagenomic sequencing projects. Using cellulases and carbonic anhydrases as two independent test cases, we demonstrated that rhModeller is much faster than HMMERmore » but with comparable accuracy, at 94.5percent and 99.9percent accuracy, respectively. More importantly, rhModeller has the ability to detect novel proteins that do not share significant homology to any known protein families. As {approx}50percent of the 2 million genes derived from the cow rumen metagenome failed to be annotated based on sequence homology, we tested whether rhModeller could be used to annotate these genes. Preliminary results suggest that rhModeller is robust in the presence of missense and frameshift mutations, two common errors in metagenomic genes. Applying the pipeline to the cow rumen genes identified 4,990 novel cellulases candidates and 8,196 novel carbonic anhydrase candidates.In summary, we expect rhModeller to dramatically increase the speed and quality of metagnomic gene annotation.« less

Cloning and nucleotide sequence of the Pseudomonas aeruginosa glucose-selective OprB porin gene and distribution of OprB within the family Pseudomonadaceae.

PubMed

Wylie, J L; Worobec, E A

1994-03-01

OprB is a glucose-selective porin known to be produced by Pseudomonas aeruginosa and Pseudomonas putida. We have cloned and sequenced the oprB gene of P. aeruginosa and obtained expression of OprB in Escherichia coli. The mature protein consists of 423 amino acid residues with a deduced molecular mass of 47597 Da. Several clusters of amino acid residues, potentially involved in the structure or function of the protein, were identified. An area of regional homology with E. coli LamB was also identified. Carbohydrate-inducible proteins, potentially homologous to OprB, were identified in several rRNA homology-group-I pseudomonads by sodium dodecyl sulfate/polyacrylamide gel electrophoresis analysis, Western immunoblotting and N-terminal amino acid sequencing. These species also contained DNA that hybridized to a P. aeruginosa oprB gene probe.

Neural network and SVM classifiers accurately predict lipid binding proteins, irrespective of sequence homology.

PubMed

Bakhtiarizadeh, Mohammad Reza; Moradi-Shahrbabak, Mohammad; Ebrahimi, Mansour; Ebrahimie, Esmaeil

2014-09-07

Due to the central roles of lipid binding proteins (LBPs) in many biological processes, sequence based identification of LBPs is of great interest. The major challenge is that LBPs are diverse in sequence, structure, and function which results in low accuracy of sequence homology based methods. Therefore, there is a need for developing alternative functional prediction methods irrespective of sequence similarity. To identify LBPs from non-LBPs, the performances of support vector machine (SVM) and neural network were compared in this study. Comprehensive protein features and various techniques were employed to create datasets. Five-fold cross-validation (CV) and independent evaluation (IE) tests were used to assess the validity of the two methods. The results indicated that SVM outperforms neural network. SVM achieved 89.28% (CV) and 89.55% (IE) overall accuracy in identification of LBPs from non-LBPs and 92.06% (CV) and 92.90% (IE) (in average) for classification of different LBPs classes. Increasing the number and the range of extracted protein features as well as optimization of the SVM parameters significantly increased the efficiency of LBPs class prediction in comparison to the only previous report in this field. Altogether, the results showed that the SVM algorithm can be run on broad, computationally calculated protein features and offers a promising tool in detection of LBPs classes. The proposed approach has the potential to integrate and improve the common sequence alignment based methods. Copyright © 2014 Elsevier Ltd. All rights reserved.

The N-terminal sequence of ribosomal protein L10 from the archaebacterium Halobacterium marismortui and its relationship to eubacterial protein L6 and other ribosomal proteins.

PubMed

Dijk, J; van den Broek, R; Nasiulas, G; Beck, A; Reinhardt, R; Wittmann-Liebold, B

1987-08-01

The amino-terminal sequence of ribosomal protein L10 from Halobacterium marismortui has been determined up to residue 54, using both a liquid- and a gas-phase sequenator. The two sequences are in good agreement. The protein is clearly homologous to protein HcuL10 from the related strain Halobacterium cutirubrum. Furthermore, a weaker but distinct homology to ribosomal protein L6 from Escherichia coli and Bacillus stearothermophilus can be detected. In addition to 7 identical amino acids in the first 36 residues in all four sequences a number of conservative replacements occurs, of mainly hydrophobic amino acids. In this common region the pattern of conserved amino acids suggests the presence of a beta-alpha fold as it occurs in ribosomal proteins L12 and L30. Furthermore, several potential cases of homology to other ribosomal components of the three ur-kingdoms have been found.

Production of Fatty Acid Components of Meadowfoam Oil in Somatic Soybean Embryos

PubMed Central

Cahoon, Edgar B.; Marillia, Elizabeth-France; Stecca, Kevin L.; Hall, Sarah E.; Taylor, David C.; Kinney, Anthony J.

2000-01-01

The seed oil of meadowfoam (Limnanthes alba) and other Limnanthes spp. is enriched in the unusual fatty acid Δ5-eicosenoic acid (20:1Δ5). This fatty acid has physical and chemical properties that make the seed oil of these plants useful for a number of industrial applications. An expressed sequence tag approach was used to identify cDNAs for enzymes involved in the biosynthesis of 20:1Δ5). By random sequencing of a library prepared from developing Limnanthes douglasii seeds, a class of cDNAs was identified that encode a homolog of acyl-coenzyme A (CoA) desaturases found in animals, fungi, and cyanobacteria. Expression of a cDNA for the L. douglasii acyl-CoA desaturase homolog in somatic soybean (Glycine max) embryos behind a strong seed-specific promoter resulted in the accumulation of Δ5-hexadecenoic acid to amounts of 2% to 3% (w/w) of the total fatty acids of single embryos. Δ5-Octadecenoic acid and 20:1Δ5 also composed <1% (w/w) each of the total fatty acids of these embryos. In addition, cDNAs were identified from the L. douglasii expressed sequence tags that encode a homolog of fatty acid elongase 1 (FAE1), a β-ketoacyl-CoA synthase that catalyzes the initial step of very long-chain fatty acid synthesis. Expression of the L. douglassi FAE1 homolog in somatic soybean embryos was accompanied by the accumulation of C20 and C22 fatty acids, principally as eicosanoic acid, to amounts of 18% (w/w) of the total fatty acids of single embryos. To partially reconstruct the biosynthetic pathway of 20:1Δ5 in transgenic plant tissues, cDNAs for the L. douglasii acyl-CoA desaturase and FAE1 were co-expressed in somatic soybean embryos. In the resulting transgenic embryos, 20:1Δ5 and Δ5-docosenoic acid composed up to 12% of the total fatty acids. PMID:10982439

Production of fatty acid components of meadowfoam oil in somatic soybean embryos.

PubMed

Cahoon, E B; Marillia, E F; Stecca, K L; Hall, S E; Taylor, D C; Kinney, A J

2000-09-01

The seed oil of meadowfoam (Limnanthes alba) and other Limnanthes spp. is enriched in the unusual fatty acid Delta(5)-eicosenoic acid (20:1Delta(5)). This fatty acid has physical and chemical properties that make the seed oil of these plants useful for a number of industrial applications. An expressed sequence tag approach was used to identify cDNAs for enzymes involved in the biosynthesis of 20:1Delta(5)). By random sequencing of a library prepared from developing Limnanthes douglasii seeds, a class of cDNAs was identified that encode a homolog of acyl-coenzyme A (CoA) desaturases found in animals, fungi, and cyanobacteria. Expression of a cDNA for the L. douglasii acyl-CoA desaturase homolog in somatic soybean (Glycine max) embryos behind a strong seed-specific promoter resulted in the accumulation of Delta(5)-hexadecenoic acid to amounts of 2% to 3% (w/w) of the total fatty acids of single embryos. Delta(5)-Octadecenoic acid and 20:1Delta(5) also composed <1% (w/w) each of the total fatty acids of these embryos. In addition, cDNAs were identified from the L. douglasii expressed sequence tags that encode a homolog of fatty acid elongase 1 (FAE1), a beta-ketoacyl-CoA synthase that catalyzes the initial step of very long-chain fatty acid synthesis. Expression of the L. douglassi FAE1 homolog in somatic soybean embryos was accompanied by the accumulation of C(20) and C(22) fatty acids, principally as eicosanoic acid, to amounts of 18% (w/w) of the total fatty acids of single embryos. To partially reconstruct the biosynthetic pathway of 20:1Delta(5) in transgenic plant tissues, cDNAs for the L. douglasii acyl-CoA desaturase and FAE1 were co-expressed in somatic soybean embryos. In the resulting transgenic embryos, 20:1Delta(5) and Delta(5)-docosenoic acid composed up to 12% of the total fatty acids.

Statistical alignment: computational properties, homology testing and goodness-of-fit.

PubMed

Hein, J; Wiuf, C; Knudsen, B; Møller, M B; Wibling, G

2000-09-08

The model of insertions and deletions in biological sequences, first formulated by Thorne, Kishino, and Felsenstein in 1991 (the TKF91 model), provides a basis for performing alignment within a statistical framework. Here we investigate this model.Firstly, we show how to accelerate the statistical alignment algorithms several orders of magnitude. The main innovations are to confine likelihood calculations to a band close to the similarity based alignment, to get good initial guesses of the evolutionary parameters and to apply an efficient numerical optimisation algorithm for finding the maximum likelihood estimate. In addition, the recursions originally presented by Thorne, Kishino and Felsenstein can be simplified. Two proteins, about 1500 amino acids long, can be analysed with this method in less than five seconds on a fast desktop computer, which makes this method practical for actual data analysis.Secondly, we propose a new homology test based on this model, where homology means that an ancestor to a sequence pair can be found finitely far back in time. This test has statistical advantages relative to the traditional shuffle test for proteins.Finally, we describe a goodness-of-fit test, that allows testing the proposed insertion-deletion (indel) process inherent to this model and find that real sequences (here globins) probably experience indels longer than one, contrary to what is assumed by the model. Copyright 2000 Academic Press.

A novel mutation in TFL1 homolog affecting determinacy in cowpea (Vigna unguiculata).

PubMed

Dhanasekar, P; Reddy, K S

2015-02-01

Mutations in the widely conserved Arabidopsis Terminal Flower 1 (TFL1) gene and its homologs have been demonstrated to result in determinacy across genera, the knowledge of which is lacking in cowpea. Understanding the molecular events leading to determinacy of apical meristems could hasten development of cowpea varieties with suitable ideotypes. Isolation and characterization of a novel mutation in cowpea TFL1 homolog (VuTFL1) affecting determinacy is reported here for the first time. Cowpea TFL1 homolog was amplified using primers designed based on conserved sequences in related genera and sequence variation was analysed in three gamma ray-induced determinate mutants, their indeterminate parent "EC394763" and two indeterminate varieties. The analyses of sequence variation exposed a novel SNP distinguishing the determinate mutants from the indeterminate types. The non-synonymous point mutation in exon 4 at position 1,176 resulted from transversion of cytosine (C) to adenine (A) leading to an amino acid change (Pro-136 to His) in determinate mutants. The effect of the mutation on protein function and stability was predicted to be detrimental using different bioinformatics/computational tools. The functionally significant novel substitution mutation is hypothesized to affect determinacy in the cowpea mutants. Development of suitable regeneration protocols in this hitherto recalcitrant crop and subsequent complementation assay in mutants or over-expressing assay in parents could decisively conclude the role of the SNP in regulating determinacy in these cowpea mutants.

Odor detection of mixtures of homologous carboxylic acids and coffee aroma compounds by humans.

PubMed

Miyazawa, Toshio; Gallagher, Michele; Preti, George; Wise, Paul M

2009-11-11

Mixture summation among homologous carboxylic acids, that is, the relationship between detection probabilities for mixtures and detection probabilities for their unmixed components, varies with similarity in carbon-chain length. The current study examined detection of acetic, butyric, hexanoic, and octanoic acids mixed with three other model odorants that differ greatly from the acids in both structure and odor character, namely, 2-hydroxy-3-methylcyclopent-2-en-1-one, furan-2-ylmethanethiol, and (3-methyl-3-sulfanylbutyl) acetate. Psychometric functions were measured for both single compounds and binary mixtures (2 of 5, forced-choice method). An air dilution olfactometer delivered stimuli, with vapor-phase calibration using gas chromatography-mass spectrometry. Across the three odorants that differed from the acids, acetic and butyric acid showed approximately additive (or perhaps even supra-additive) summation at low perithreshold concentrations, but subadditive interactions at high perithreshold concentrations. In contrast, the medium-chain acids showed subadditive interactions across a wide range of concentrations. Thus, carbon-chain length appears to influence not only summation with other carboxylic acids but also summation with at least some unrelated compounds.

An oleate 12-hydroxylase from Ricinus communis L. is a fatty acyl desaturase homolog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van De Loo, F.J.; Broun, P.; Turner, S.

1995-07-18

Recent spectroscopic evidence implicating a binuclear iron site at the reaction center of fatty acyl desaturases suggested to us that certain fatty acyl hydroxylases may share significant amino acid sequence similarity with desaturases. To test this theory, we prepared a cDNA library from developing endosperm of the castor-oil plant (Ricinus communis L.) and obtained partial nucleotide sequences for 468 anonymous clones that were not expressed at high levels in leaves, a tissue deficient in 12-hydroxyoleic acid. This resulted in the identification of several cDNA clones encoding a polypeptide of 387 amino acids with a predicted molecular weight of 44,407 andmore » with {approx}67% sequence homology to microsomal oleate desaturase from Arabidopsis. Expression of a full-length clone under control of the cauliflower mosaic virus 35S promoter in transgenic tobacco resulted in the accumulation of low levels of 12-hydroxyoleic acid in seeds, indicating that the clone encodes the castor oleate hydroxylase. These results suggest that fatty acyl desaturases and hydroxylases share similar reaction mechanisms and provide an example of enzyme evolution. 26 refs., 6 figs., 1 tab.« less

Kit for detecting nucleic acid sequences using competitive hybridization probes

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

2001-01-01

A kit is provided for detecting a target nucleic acid sequence in a sample, the kit comprising: a first hybridization probe which includes a nucleic acid sequence that is sufficiently complementary to selectively hybridize to a first portion of the target sequence, the first hybridization probe including a first complexing agent for forming a binding pair with a second complexing agent; and a second hybridization probe which includes a nucleic acid sequence that is sufficiently complementary to selectively hybridize to a second portion of the target sequence to which the first hybridization probe does not selectively hybridize, the second hybridization probe including a detectable marker; a third hybridization probe which includes a nucleic acid sequence that is sufficiently complementary to selectively hybridize to a first portion of the target sequence, the third hybridization probe including the same detectable marker as the second hybridization probe; and a fourth hybridization probe which includes a nucleic acid sequence that is sufficiently complementary to selectively hybridize to a second portion of the target sequence to which the third hybridization probe does not selectively hybridize, the fourth hybridization probe including the first complexing agent for forming a binding pair with the second complexing agent; wherein the first and second hybridization probes are capable of simultaneously hybridizing to the target sequence and the third and fourth hybridization probes are capable of simultaneously hybridizing to the target sequence, the detectable marker is not present on the first or fourth hybridization probes and the first, second, third, and fourth hybridization probes each include a competitive nucleic acid sequence which is sufficiently complementary to a third portion of the target sequence that the competitive sequences of the first, second, third, and fourth hybridization probes compete with each other to hybridize to the third portion of the

Sequence of a cDNA encoding pancreatic preprosomatostatin-22.

PubMed Central

Magazin, M; Minth, C D; Funckes, C L; Deschenes, R; Tavianini, M A; Dixon, J E

1982-01-01

We report the nucleotide sequence of a precursor to somatostatin that upon proteolytic processing may give rise to a hormone of 22 amino acids. The nucleotide sequence of a cDNA from the channel catfish (Ictalurus punctatus) encodes a precursor to somatostatin that is 105 amino acids (Mr, 11,500). The cDNA coding for somatostatin-22 consists of 36 nucleotides in the 5' untranslated region, 315 nucleotides that code for the precursor to somatostatin-22, 269 nucleotides at the 3' untranslated region, and a variable length of poly(A). The putative preprohormone contains a sequence of hydrophobic amino acids at the amino terminus that has the properties of a "signal" peptide. A connecting sequence of approximately 57 amino acids is followed by a single Arg-Arg sequence, which immediately precedes the hormone. Somatostatin-22 is homologous to somatostatin-14 in 7 of the 14 amino acids, including the Phe-Trp-Lys sequence. Hybridization selection of mRNA, followed by its translation in a wheat germ cell-free system, resulted in the synthesis of a single polypeptide having a molecular weight of approximately 10,000 as estimated on Na-DodSO4/polyacrylamide gels. Images PMID:6127673

Invariant glycines and prolines flanking in loops the strand beta 2 of various (alpha/beta)8-barrel enzymes: a hidden homology?

PubMed Central

Janecek, S.

1996-01-01

The question of parallel (alpha/beta)8-barrel fold evolution remains unclear, owing mainly to the lack of sequence homology throughout the amino acid sequences of (alpha/beta)8-barrel enzymes. The "classical" approaches used in the search for homologies among (alpha/beta)8-barrels (e.g., production of structurally based alignments) have yielded alignments perfect from the structural point of view, but the approaches have been unable to reveal the homologies. These are proposed to be "hidden" in (alpha/beta)8-barrel enzymes. The term "hidden homology" means that the alignment of sequence stretches proposed to be homologous need not be structurally fully satisfactory. This is due to the very long evolutionary history of all (alpha/beta)8-barrels. This work identifies so-called hidden homology around the strand beta 2 that is flanked by loops containing invariant glycines and prolines in 17 different (alpha/beta)8-barrel enzymes, i.e., roughly in half of all currently known (alpha/beta)8-barrel proteins. The search was based on the idea that a conserved sequence region of an (alpha/beta)8-barrel enzyme should be more or less conserved also in the equivalent part of the structure of the other enzymes with this folding motif, given their mutual evolutionary relatedness. For this purpose, the sequence region around the well-conserved second beta-strand of alpha-amylase flanked by the invariant glycine and proline (56_GFTAIWITP, Aspergillus oryzae alpha-amylase numbering), was used as the sequence-structural template. The proposal that the second beta-strand of (alpha/beta)8-barrel fold is important from the evolutionary point of view is strongly supported by the increasing trend of the observed beta 2-strand structural similarity for the pairs of (alpha/beta)8-barrel enzymes: alpha-amylase and the alpha-subunit of tryptophan synthase, alpha-amylase and mandelate racemase, and alpha-amylase and cyclodextrin glycosyltransferase. This trend is also in agreement with the

Invariant glycines and prolines flanking in loops the strand beta 2 of various (alpha/beta)8-barrel enzymes: a hidden homology?

PubMed

Janecek, S

1996-06-01

The question of parallel (alpha/beta)8-barrel fold evolution remains unclear, owing mainly to the lack of sequence homology throughout the amino acid sequences of (alpha/beta)8-barrel enzymes. The "classical" approaches used in the search for homologies among (alpha/beta)8-barrels (e.g., production of structurally based alignments) have yielded alignments perfect from the structural point of view, but the approaches have been unable to reveal the homologies. These are proposed to be "hidden" in (alpha/beta)8-barrel enzymes. The term "hidden homology" means that the alignment of sequence stretches proposed to be homologous need not be structurally fully satisfactory. This is due to the very long evolutionary history of all (alpha/beta)8-barrels. This work identifies so-called hidden homology around the strand beta 2 that is flanked by loops containing invariant glycines and prolines in 17 different (alpha/beta)8-barrel enzymes, i.e., roughly in half of all currently known (alpha/beta)8-barrel proteins. The search was based on the idea that a conserved sequence region of an (alpha/beta)8-barrel enzyme should be more or less conserved also in the equivalent part of the structure of the other enzymes with this folding motif, given their mutual evolutionary relatedness. For this purpose, the sequence region around the well-conserved second beta-strand of alpha-amylase flanked by the invariant glycine and proline (56_GFTAIWITP, Aspergillus oryzae alpha-amylase numbering), was used as the sequence-structural template. The proposal that the second beta-strand of (alpha/beta)8-barrel fold is important from the evolutionary point of view is strongly supported by the increasing trend of the observed beta 2-strand structural similarity for the pairs of (alpha/beta)8-barrel enzymes: alpha-amylase and the alpha-subunit of tryptophan synthase, alpha-amylase and mandelate racemase, and alpha-amylase and cyclodextrin glycosyltransferase. This trend is also in agreement with the

Partial mapping and sequencing of a fish iridovirus genome reveals genes homologous to the frog virus 3 p31, p40 and human eIF2alpha.

PubMed

Yu, Y X; Béarzotti, M; Vende, P; Ahne, W; Brémont, M

1999-09-01

Iridovirus-like pathogens have been recognized as a cause of serious systemic diseases among feral, cultured and ornamental fish in the recent years. Mortalities of fish due to systemic iridovirus infection reaching 30-100% were observed in Europe, Australia, Japan and Thailand. Up to now, the molecular biology of these important pathogens has been poorly documented. To get better insights on the genomic organization of these piscine iridoviruses, we have constructed a cosmid viral DNA library from the epizootic hematopoietic necrosis virus (EHNV). Two recombinant cosmids (Cos7 and Cos12) have been selected for systematic sequencing. Cos7 and 12 are localized side by side along the genome and cover the 2/3 part of the total EHNV genome which has been estimated to be approximately 101.47 kb in length. Thirty five kilobase pairs (kbps) from Cos7 and 10 kbps from Cos12 have been determined. Sequence analysis revealed open reading frames (ORF) sharing homologies with sequences from the Frog virus 3 such as the p31 and p40 proteins. Among the others identified ORFs, some of them presented homologies with known protein sequences, such as the human eIF2alpha protein, and some did not show any significant homologies with sequences available in the databases. But, none were related to Lymphocystis virus, a member of the Iridoviridae family, for which the full genome nucleotide sequence has been determined.

[Sequencing and analysis of the complete genome of a rabies virus isolate from Sika deer].

PubMed

Zhao, Yun-Jiao; Guo, Li; Huang, Ying; Zhang, Li-Shi; Qian, Ai-Dong

2008-05-01

One DRV strain was isolated from Sika Deer brain and sequenced. Nine overlapped gene fragments were amplified by RT-PCR through 3'-RACE and 5'-RACE method, and the complete DRV genome sequence was assembled. The length of the complete genome is 11863bp. The DRV genome organization was similar to other rabies viruses which were composed of five genes and the initiation sites and termination sites were highly conservative. There were mutated amino acids in important antigen sites of nucleoprotein and glycoprotein. The nucleotide and amino acid homologies of gene N, P, M, G, L in strains with completed genomie sequencing were compared. Compared with N gene sequence of other typical rabies viruses, a phylogenetic tree was established . These results indicated that DRV belonged to gene type 1. The highest homology compared with Chinese vaccine strain 3aG was 94%, and the lowest was 71% compared with WCBV. These findings provided theoretical reference for further research in rabies virus.

The primary structures of two yeast enolase genes. Homology between the 5' noncoding flanking regions of yeast enolase and glyceraldehyde-3-phosphate dehydrogenase genes.

PubMed

Holland, M J; Holland, J P; Thill, G P; Jackson, K A

1981-02-10

Segments of yeast genomic DNA containing two enolase structural genes have been isolated by subculture cloning procedures using a cDNA hybridization probe synthesized from purified yeast enolase mRNA. Based on restriction endonuclease and transcriptional maps of these two segments of yeast DNA, each hybrid plasmid contains a region of extensive nucleotide sequence homology which forms hybrids with the cDNA probe. The DNA sequences which flank this homologous region in the two hybrid plasmids are nonhomologous indicating that these sequences are nontandemly repeated in the yeast genome. The complete nucleotide sequence of the coding as well as the flanking noncoding regions of these genes has been determined. The amino acid sequence predicted from one reading frame of both structural genes is extremely similar to that determined for yeast enolase (Chin, C. C. Q., Brewer, J. M., Eckard, E., and Wold, F. (1981) J. Biol. Chem. 256, 1370-1376), confirming that these isolated structural genes encode yeast enolase. The nucleotide sequences of the coding regions of the genes are approximately 95% homologous, and neither gene contains an intervening sequence. Codon utilization in the enolase genes follows the same biased pattern previously described for two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes (Holland, J. P., and Holland, M. J. (1980) J. Biol. Chem. 255, 2596-2605). DNA blotting analysis confirmed that the isolated segments of yeast DNA are colinear with yeast genomic DNA and that there are two nontandemly repeated enolase genes per haploid yeast genome. The noncoding portions of the two enolase genes adjacent to the initiation and termination codons are approximately 70% homologous and contain sequences thought to be involved in the synthesis and processing messenger RNA. Finally there are regions of extensive homology between the two enolase structural genes and two yeast glyceraldehyde-3-phosphate dehydrogenase structural genes within the 5

Genomic cloning and chromosomal localization of HRY, the human homolog to the Drosophila segmentation gene, hairy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feder, J.N.; Jan, L.Y.; Jan, Y.N.

The Drosophila hairy gene encodes a basic helix- loop-helix protein that functions in at least two steps during Drosophila development: (1) during embryogenesis, when it partakes in the establishment of segments, and (2) during the larval stage, when it functions negatively in determining the pattern of sensory bristles on the adult fly. In the rat, a structurally homologous gene (RHL) behaves as an immediate-early gene in its response to growth factors and can, like that in Drosophila, suppress neuronal differentiation events. Here, the authors report the genomic cloning of the human hairy gene homolog (HRY). The coding region of themore » gene is contained within four exons. The predicted amino acid sequence reveals only four amino acid differences between the human and rat genes. Analysis of the DNA sequence 5[prime] to the coding region reveals a putatitve untranslated exon. To increase the value of the HRY gene as a genetic marker and to assess its potential involvement in genetic disorders, they sublocalized the locus to chromosome 3q28-q29 by fluorescence in situ hybridization. 34 refs., 4 figs., 1 tab.« less

PCV: An Alignment Free Method for Finding Homologous Nucleotide Sequences and its Application in Phylogenetic Study.

PubMed

Kumar, Rajnish; Mishra, Bharat Kumar; Lahiri, Tapobrata; Kumar, Gautam; Kumar, Nilesh; Gupta, Rahul; Pal, Manoj Kumar

2017-06-01

Online retrieval of the homologous nucleotide sequences through existing alignment techniques is a common practice against the given database of sequences. The salient point of these techniques is their dependence on local alignment techniques and scoring matrices the reliability of which is limited by computational complexity and accuracy. Toward this direction, this work offers a novel way for numerical representation of genes which can further help in dividing the data space into smaller partitions helping formation of a search tree. In this context, this paper introduces a 36-dimensional Periodicity Count Value (PCV) which is representative of a particular nucleotide sequence and created through adaptation from the concept of stochastic model of Kolekar et al. (American Institute of Physics 1298:307-312, 2010. doi: 10.1063/1.3516320 ). The PCV construct uses information on physicochemical properties of nucleotides and their positional distribution pattern within a gene. It is observed that PCV representation of gene reduces computational cost in the calculation of distances between a pair of genes while being consistent with the existing methods. The validity of PCV-based method was further tested through their use in molecular phylogeny constructs in comparison with that using existing sequence alignment methods.

DNA sequences of three beta-1,4-endoglucanase genes from Thermomonospora fusca.

PubMed Central

Lao, G; Ghangas, G S; Jung, E D; Wilson, D B

1991-01-01

The DNA sequences of the Thermomonospora fusca genes encoding cellulases E2 and E5 and the N-terminal end of E4 were determined. Each sequence contains an identical 14-bp inverted repeat upstream of the initiation codon. There were no significant homologies between the coding regions of the three genes. The E2 gene is 73% identical to the celA gene from Microbispora bispora, but this was the only homology found with other cellulase genes. E2 belongs to a family of cellulases that includes celA from M. bispora, cenA from Cellulomonas fimi, casA from an alkalophilic Streptomyces strain, and cellobiohydrolase II from Trichoderma reesei. E4 shows 44% identity to an avocado cellulase, while E5 belongs to the Bacillus cellulase family. There were strong similarities between the amino acid sequences of the E2 and E5 cellulose binding domains, and these regions also showed homology with C. fimi and Pseudomonas fluorescens cellulose binding domains. PMID:1904434

Productive Homologous and Non-homologous Recombination of Hepatitis C Virus in Cell Culture

PubMed Central

Li, Yi-Ping; Mikkelsen, Lotte S.; Gottwein, Judith M.; Bukh, Jens

2013-01-01

Genetic recombination is an important mechanism for increasing diversity of RNA viruses, and constitutes a viral escape mechanism to host immune responses and to treatment with antiviral compounds. Although rare, epidemiologically important hepatitis C virus (HCV) recombinants have been reported. In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13–36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6 sequence from the 5′ end to the NS2–NS3 region followed by JFH1 sequence from Core to the 3′ end. These recombinants carried duplicated sequence of up to 2400 nucleotides. HCV replication was not required for recombination, as recombinants were observed in most experiments even when two replication incompetent genomes were co-transfected. Reverse genetic studies verified the viability of representative recombinants. After serial passage, subsequent recombination events reducing or eliminating the duplicated region were observed for some but not all recombinants. Furthermore, we found that inter-genotypic recombination could occur, but at a lower frequency than intra-genotypic recombination. Productive recombination of attenuated HCV genomes depended on expression of all HCV proteins and tolerated duplicated sequence. In general, no strong site specificity was observed. Non-homologous recombination was observed in most cases, while few homologous events were identified. A better understanding of HCV recombination could help identification of natural recombinants

A discriminative method for family-based protein remote homology detection that combines inductive logic programming and propositional models

PubMed Central

2011-01-01

Background Remote homology detection is a hard computational problem. Most approaches have trained computational models by using either full protein sequences or multiple sequence alignments (MSA), including all positions. However, when we deal with proteins in the "twilight zone" we can observe that only some segments of sequences (motifs) are conserved. We introduce a novel logical representation that allows us to represent physico-chemical properties of sequences, conserved amino acid positions and conserved physico-chemical positions in the MSA. From this, Inductive Logic Programming (ILP) finds the most frequent patterns (motifs) and uses them to train propositional models, such as decision trees and support vector machines (SVM). Results We use the SCOP database to perform our experiments by evaluating protein recognition within the same superfamily. Our results show that our methodology when using SVM performs significantly better than some of the state of the art methods, and comparable to other. However, our method provides a comprehensible set of logical rules that can help to understand what determines a protein function. Conclusions The strategy of selecting only the most frequent patterns is effective for the remote homology detection. This is possible through a suitable first-order logical representation of homologous properties, and through a set of frequent patterns, found by an ILP system, that summarizes essential features of protein functions. PMID:21429187

A discriminative method for family-based protein remote homology detection that combines inductive logic programming and propositional models.

PubMed

Bernardes, Juliana S; Carbone, Alessandra; Zaverucha, Gerson

2011-03-23

Remote homology detection is a hard computational problem. Most approaches have trained computational models by using either full protein sequences or multiple sequence alignments (MSA), including all positions. However, when we deal with proteins in the "twilight zone" we can observe that only some segments of sequences (motifs) are conserved. We introduce a novel logical representation that allows us to represent physico-chemical properties of sequences, conserved amino acid positions and conserved physico-chemical positions in the MSA. From this, Inductive Logic Programming (ILP) finds the most frequent patterns (motifs) and uses them to train propositional models, such as decision trees and support vector machines (SVM). We use the SCOP database to perform our experiments by evaluating protein recognition within the same superfamily. Our results show that our methodology when using SVM performs significantly better than some of the state of the art methods, and comparable to other. However, our method provides a comprehensible set of logical rules that can help to understand what determines a protein function. The strategy of selecting only the most frequent patterns is effective for the remote homology detection. This is possible through a suitable first-order logical representation of homologous properties, and through a set of frequent patterns, found by an ILP system, that summarizes essential features of protein functions.

Prefiltering Model for Homology Detection Algorithms on GPU.

PubMed

Retamosa, Germán; de Pedro, Luis; González, Ivan; Tamames, Javier

2016-01-01

Homology detection has evolved over the time from heavy algorithms based on dynamic programming approaches to lightweight alternatives based on different heuristic models. However, the main problem with these algorithms is that they use complex statistical models, which makes it difficult to achieve a relevant speedup and find exact matches with the original results. Thus, their acceleration is essential. The aim of this article was to prefilter a sequence database. To make this work, we have implemented a groundbreaking heuristic model based on NVIDIA's graphics processing units (GPUs) and multicore processors. Depending on the sensitivity settings, this makes it possible to quickly reduce the sequence database by factors between 50% and 95%, while rejecting no significant sequences. Furthermore, this prefiltering application can be used together with multiple homology detection algorithms as a part of a next-generation sequencing system. Extensive performance and accuracy tests have been carried out in the Spanish National Centre for Biotechnology (NCB). The results show that GPU hardware can accelerate the execution times of former homology detection applications, such as National Centre for Biotechnology Information (NCBI), Basic Local Alignment Search Tool for Proteins (BLASTP), up to a factor of 4.

Developmental rearrangement of cyanobacterial nif genes: nucleotide sequence, open reading frames, and cytochrome P-450 homology of the Anabaena sp. strain PCC 7120 nifD element.

PubMed Central

Lammers, P J; McLaughlin, S; Papin, S; Trujillo-Provencio, C; Ryncarz, A J

1990-01-01

An 11-kbp DNA element of unknown function interrupts the nifD gene in vegetative cells of Anabaena sp. strain PCC 7120. In developing heterocysts the nifD element excises from the chromosome via site-specific recombination between short repeat sequences that flank the element. The nucleotide sequence of the nifH-proximal half of the element was determined to elucidate the genetic potential of the element. Four open reading frames with the same relative orientation as the nifD element-encoded xisA gene were identified in the sequenced region. Each of the open reading frames was preceded by a reasonable ribosome-binding site and had biased codon utilization preferences consistent with low levels of expression. Open reading frame 3 was highly homologous with three cytochrome P-450 omega-hydroxylase proteins and showed regional homology to functionally significant domains common to the cytochrome P-450 superfamily. The sequence encoding open reading frame 2 was the most highly conserved portion of the sequenced region based on heterologous hybridization experiments with three genera of heterocystous cyanobacteria. Images PMID:2123860

High-efficiency transformation of Pichia stipitis based on its URA3 gene and a homologous autonomous replication sequence, ARS2.

PubMed Central

Yang, V W; Marks, J A; Davis, B P; Jeffries, T W

1994-01-01

This paper describes the first high-efficiency transformation system for the xylose-fermenting yeast Pichia stipitis. The system includes integrating and autonomously replicating plasmids based on the gene for orotidine-5'-phosphate decarboxylase (URA3) and an autonomous replicating sequence (ARS) element (ARS2) isolated from P. stipitis CBS 6054. Ura- auxotrophs were obtained by selecting for resistance to 5-fluoroorotic acid and were identified as ura3 mutants by transformation with P. stipitis URA3. P. stipitis URA3 was cloned by its homology to Saccharomyces cerevisiae URA3, with which it is 69% identical in the coding region. P. stipitis ARS elements were cloned functionally through plasmid rescue. These sequences confer autonomous replication when cloned into vectors bearing the P. stipitis URA3 gene. P. stipitis ARS2 has features similar to those of the consensus ARS of S. cerevisiae and other ARS elements. Circular plasmids bearing the P. stipitis URA3 gene with various amounts of flanking sequences produced 600 to 8,600 Ura+ transformants per micrograms of DNA by electroporation. Most transformants obtained with circular vectors arose without integration of vector sequences. One vector yielded 5,200 to 12,500 Ura+ transformants per micrograms of DNA after it was linearized at various restriction enzyme sites within the P. stipitis URA3 insert. Transformants arising from linearized vectors produced stable integrants, and integration events were site specific for the genomic ura3 in 20% of the transformants examined. Plasmids bearing the P. stipitis URA3 gene and ARS2 element produced more than 30,000 transformants per micrograms of plasmid DNA. Autonomously replicating plasmids were stable for at least 50 generations in selection medium and were present at an average of 10 copies per nucleus. Images PMID:7811063

Shotgun Protein Sequencing with Meta-contig Assembly*

PubMed Central

Guthals, Adrian; Clauser, Karl R.; Bandeira, Nuno

2012-01-01

Full-length de novo sequencing from tandem mass (MS/MS) spectra of unknown proteins such as antibodies or proteins from organisms with unsequenced genomes remains a challenging open problem. Conventional algorithms designed to individually sequence each MS/MS spectrum are limited by incomplete peptide fragmentation or low signal to noise ratios and tend to result in short de novo sequences at low sequencing accuracy. Our shotgun protein sequencing (SPS) approach was developed to ameliorate these limitations by first finding groups of unidentified spectra from the same peptides (contigs) and then deriving a consensus de novo sequence for each assembled set of spectra (contig sequences). But whereas SPS enables much more accurate reconstruction of de novo sequences longer than can be recovered from individual MS/MS spectra, it still requires error-tolerant matching to homologous proteins to group smaller contig sequences into full-length protein sequences, thus limiting its effectiveness on sequences from poorly annotated proteins. Using low and high resolution CID and high resolution HCD MS/MS spectra, we address this limitation with a Meta-SPS algorithm designed to overlap and further assemble SPS contigs into Meta-SPS de novo contig sequences extending as long as 100 amino acids at over 97% accuracy without requiring any knowledge of homologous protein sequences. We demonstrate Meta-SPS using distinct MS/MS data sets obtained with separate enzymatic digestions and discuss how the remaining de novo sequencing limitations relate to MS/MS acquisition settings. PMID:22798278

Shotgun protein sequencing with meta-contig assembly.

PubMed

Guthals, Adrian; Clauser, Karl R; Bandeira, Nuno

2012-10-01

Full-length de novo sequencing from tandem mass (MS/MS) spectra of unknown proteins such as antibodies or proteins from organisms with unsequenced genomes remains a challenging open problem. Conventional algorithms designed to individually sequence each MS/MS spectrum are limited by incomplete peptide fragmentation or low signal to noise ratios and tend to result in short de novo sequences at low sequencing accuracy. Our shotgun protein sequencing (SPS) approach was developed to ameliorate these limitations by first finding groups of unidentified spectra from the same peptides (contigs) and then deriving a consensus de novo sequence for each assembled set of spectra (contig sequences). But whereas SPS enables much more accurate reconstruction of de novo sequences longer than can be recovered from individual MS/MS spectra, it still requires error-tolerant matching to homologous proteins to group smaller contig sequences into full-length protein sequences, thus limiting its effectiveness on sequences from poorly annotated proteins. Using low and high resolution CID and high resolution HCD MS/MS spectra, we address this limitation with a Meta-SPS algorithm designed to overlap and further assemble SPS contigs into Meta-SPS de novo contig sequences extending as long as 100 amino acids at over 97% accuracy without requiring any knowledge of homologous protein sequences. We demonstrate Meta-SPS using distinct MS/MS data sets obtained with separate enzymatic digestions and discuss how the remaining de novo sequencing limitations relate to MS/MS acquisition settings.

Cloning, sequencing, and characterization of the Bacillus subtilis biotin biosynthetic operon.

PubMed

Bower, S; Perkins, J B; Yocum, R R; Howitt, C L; Rahaim, P; Pero, J

1996-07-01

A 10-kb region of the Bacillus subtilis genome that contains genes involved in biotin-biosynthesis was cloned and sequenced. DNA sequence analysis indicated that B. subtilis contains homologs of the Escherichia coli and Bacillus sphaericus bioA, bioB, bioD, and bioF genes. These four genes and a homolog of the B. sphaericus bioW gene are arranged in a single operon in the order bioWAFDR and are followed by two additional genes, bioI and orf2. bioI and orf2 show no similarity to any other known biotin biosynthetic genes. The bioI gene encodes a protein with similarity to cytochrome P-450s and was able to complement mutations in either bioC or bioH of E. coli. Mutations in bioI caused B. subtilis to grow poorly in the absence of biotin. The bradytroph phenotype of bioI mutants was overcome by pimelic acid, suggesting that the product of bioI functions at a step prior to pimelic acid synthesis. The B. subtilis bio operon is preceded by a putative vegetative promoter sequence and contains just downstream a region of dyad symmetry with homology to the bio regulatory region of B. sphaericus. Analysis of a bioW-lacZ translational fusion indicated that expression of the biotin operon is regulated by biotin and the B. subtilis birA gene.

Cloning, sequencing, and characterization of the Bacillus subtilis biotin biosynthetic operon.

PubMed Central

Bower, S; Perkins, J B; Yocum, R R; Howitt, C L; Rahaim, P; Pero, J

1996-01-01

A 10-kb region of the Bacillus subtilis genome that contains genes involved in biotin-biosynthesis was cloned and sequenced. DNA sequence analysis indicated that B. subtilis contains homologs of the Escherichia coli and Bacillus sphaericus bioA, bioB, bioD, and bioF genes. These four genes and a homolog of the B. sphaericus bioW gene are arranged in a single operon in the order bioWAFDR and are followed by two additional genes, bioI and orf2. bioI and orf2 show no similarity to any other known biotin biosynthetic genes. The bioI gene encodes a protein with similarity to cytochrome P-450s and was able to complement mutations in either bioC or bioH of E. coli. Mutations in bioI caused B. subtilis to grow poorly in the absence of biotin. The bradytroph phenotype of bioI mutants was overcome by pimelic acid, suggesting that the product of bioI functions at a step prior to pimelic acid synthesis. The B. subtilis bio operon is preceded by a putative vegetative promoter sequence and contains just downstream a region of dyad symmetry with homology to the bio regulatory region of B. sphaericus. Analysis of a bioW-lacZ translational fusion indicated that expression of the biotin operon is regulated by biotin and the B. subtilis birA gene. PMID:8763940

Homology among tet determinants in conjugative elements of streptococci.

PubMed Central

Smith, M D; Hazum, S; Guild, W R

1981-01-01

A mutation to tetracycline sensitivity in a resistant strain of Streptococcus pneumoniae was shown by several criteria to be due to a point mutation in the conjugative omega (cat-tet) element found in the chromosomes of strains derived from BM6001, a clinical strain resistant to tetracycline and chloramphenicol. Strains carrying the mutation were transformed back to tetracycline resistance with the high efficiency of a point marker by donor deoxyribonucleic acids from its ancestral strain and from nine other clinical isolates of pneumococcus and by deoxyribonucleic acids from group D Streptococcus faecalis and group B Streptococcus agalactiae strains that also carry conjugative tet elements in their chromosomes. It was not transformed to resistance by tet plasmid deoxyribonucleic acids from either gram-negative or gram-positive species, except for one that carried transposon Tn916, the conjugative tet element present in the chromosomes of some S. faecalis strains. The results showed that the tet determinants in conjugative elements of several streptococcal species share a high degree of deoxyribonucleic acid sequence homology and suggested that they differ from other tet genes. PMID:6270063

FASH: A web application for nucleotides sequence search.

PubMed

Veksler-Lublinksy, Isana; Barash, Danny; Avisar, Chai; Troim, Einav; Chew, Paul; Kedem, Klara

2008-05-27

: FASH (Fourier Alignment Sequence Heuristics) is a web application, based on the Fast Fourier Transform, for finding remote homologs within a long nucleic acid sequence. Given a query sequence and a long text-sequence (e.g, the human genome), FASH detects subsequences within the text that are remotely-similar to the query. FASH offers an alternative approach to Blast/Fasta for querying long RNA/DNA sequences. FASH differs from these other approaches in that it does not depend on the existence of contiguous seed-sequences in its initial detection phase. The FASH web server is user friendly and very easy to operate. FASH can be accessed athttps://fash.bgu.ac.il:8443/fash/default.jsp (secured website).

Molecular cloning, sequence identification and tissue expression profile of three novel sheep (Ovis aries) genes - BCKDHA, NAGA and HEXA.

PubMed

Liu, G Y; Gao, S Z

2009-01-01

The complete coding sequences of three sheep genes- BCKDHA, NAGA and HEXA were amplified using the reverse transcriptase polymerase chain reaction (RT-PCR), based on the conserved sequence information of the mouse or other mammals. The nucleotide sequences of these three genes revealed that the sheep BCKDHA gene encodes a protein of 313 amino acids which has high homology with the BCKDHA gene that encodes a protein of 447 amino acids that has high homology with the Branched chain keto acid dehydrogenase El, alpha polypeptide (BCKDHA) of five species chimpanzee (93%), human (96%), crab-eating macaque (93%), bovine (98%) and mouse (91%). The sheep NAGA gene encodes a protein of 411 amino acids that has high homology with the alpha-N-acetylgalactosaminidase (NAGA) of five species human (85%), bovine (94%), mouse (91%), rat (83%) and chicken (74%). The sheep HEXA gene encodes a protein of 529 amino acids that has high homology with the hexosaminidase A(HEXA) of five species bovine (98%), human (84%), Bornean orangután (84%), rat (80%) and mouse (81%). Finally these three novel sheep genes were assigned to GenelDs: 100145857, 100145858 and 100145856. The phylogenetic tree analysis revealed that the sheep BCKDHA, NAGA, and HEXA all have closer genetic relationships to the BCKDHA, NAGA, and HEXA of bovine. Tissue expression profile analysis was also carried out and results revealed that sheep BCKDHA, NAGA and HEXA genes were differentially expressed in tissues including muscle, heart, liver, fat, kidney, lung, small and large intestine. Our experiment is the first to establish the primary foundation for further research on these three sheep genes.

A greedy, graph-based algorithm for the alignment of multiple homologous gene lists.

PubMed

Fostier, Jan; Proost, Sebastian; Dhoedt, Bart; Saeys, Yvan; Demeester, Piet; Van de Peer, Yves; Vandepoele, Klaas

2011-03-15

Many comparative genomics studies rely on the correct identification of homologous genomic regions using accurate alignment tools. In such case, the alphabet of the input sequences consists of complete genes, rather than nucleotides or amino acids. As optimal multiple sequence alignment is computationally impractical, a progressive alignment strategy is often employed. However, such an approach is susceptible to the propagation of alignment errors in early pairwise alignment steps, especially when dealing with strongly diverged genomic regions. In this article, we present a novel accurate and efficient greedy, graph-based algorithm for the alignment of multiple homologous genomic segments, represented as ordered gene lists. Based on provable properties of the graph structure, several heuristics are developed to resolve local alignment conflicts that occur due to gene duplication and/or rearrangement events on the different genomic segments. The performance of the algorithm is assessed by comparing the alignment results of homologous genomic segments in Arabidopsis thaliana to those obtained by using both a progressive alignment method and an earlier graph-based implementation. Especially for datasets that contain strongly diverged segments, the proposed method achieves a substantially higher alignment accuracy, and proves to be sufficiently fast for large datasets including a few dozens of eukaryotic genomes. http://bioinformatics.psb.ugent.be/software. The algorithm is implemented as a part of the i-ADHoRe 3.0 package.

Isolation and characterization of rhamnose-binding lectins from eggs of steelhead trout (Oncorhynchus mykiss) homologous to low density lipoprotein receptor superfamily.

PubMed

Tateno, H; Saneyoshi, A; Ogawa, T; Muramoto, K; Kamiya, H; Saneyoshi, M

1998-07-24

Two L-rhamnose-binding lectins named STL1 and STL2 were isolated from eggs of steelhead trout (Oncorhynchus mykiss) by affinity chromatography and ion exchange chromatography. The apparent molecular masses of purified STL1 and STL2 were estimated to be 84 and 68 kDa, respectively, by gel filtration chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and matrix-assisted laser desorption ionization time of flight mass spectrometry of these lectins revealed that STL1 was composed of noncovalently linked trimer of 31.4-kDa subunits, and STL2 was noncovalently linked trimer of 21.5-kDa subunits. The minimum concentrations of STL1, a major component, and STL2, a minor component, needed to agglutinate rabbit erythrocytes were 9 and 0.2 microg/ml, respectively. The most effective saccharide in the hemagglutination inhibition assay for both STL1 and STL2 was L-rhamnose. Saccharides possessing the same configuration of hydroxyl groups at C2 and C4 as that in L-rhamnose, such as L-arabinose and D-galactose, also inhibited. The amino acid sequence of STL2 was determined by analysis of peptides generated by digestion of the S-carboxamidomethylated protein with Achromobacter protease I or Staphylococcus aureus V8 protease. The STL2 subunit of 195 amino acid residues proved to have a unique polypeptide architecture; that is, it was composed of two tandemly repeated homologous domains (STL2-N and STL2-C) with 52% internal homology. These two domains showed a sequence homology to the subunit (105 amino acid residues) of D-galactoside-specific sea urchin (Anthocidaris crassispina) egg lectin (37% for STL2-N and 46% for STL2-C, respectively). The N terminus of the STL1 subunit was blocked with an acetyl group. However, a partial amino acid sequence of the subunit showed a sequence similarity to STL2. Moreover, STL2 also showed a sequence homology to the ligand binding domain of the vitellogenin receptor. We have also employed surface plasmon resonance biosensor

Hybridization and sequencing of nucleic acids using base pair mismatches

DOEpatents

Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

2001-01-01

Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

Peak AAA fatty acid homolog contaminants present in the dietary supplement l-Tryptophan associated with the onset of eosinophilia-myalgia syndrome.

PubMed

Klarskov, Klaus; Gagnon, Hugo; Racine, Mathieu; Boudreault, Pierre-Luc; Normandin, Chad; Marsault, Eric; Gleich, Gerald J; Naylor, Stephen

2018-05-22

The eosinophilia-myalgia syndrome (EMS) outbreak that occurred in the USA and elsewhere in 1989 was caused by the ingestion of Showa Denko K.K. (SD) L-tryptophan (L-Trp). "Six compounds" detected in the L-Trp were reported as case-associated contaminants. Recently the final and most statistically significant contaminant, "Peak AAA" was structurally characterized. The "compound" was actually shown to be two structural isomers resulting from condensation reactions of L-Trp with fatty acids derived from the bacterial cell membrane. They were identified as the indole C-2 anteiso (AAA 1 -343) and linear (AAA 2 -343) aliphatic chain isomers. Based on those findings, we utilized a combination of on-line HPLC-electrospray ionization mass spectrometry (LC-MS), as well as both precursor and product ion tandem mass spectrometry (MS/MS) to facilitate identification of a homologous family of condensation products related to AAA 1 -343 and AAA 2 -343. We structurally characterized eight new AAA 1 -XXX/AAA 2 -XXX contaminants, where XXX represents the integer molecular ions of all the related homologs, differing by aliphatic chain length and isomer configuration. The contaminants were derived from the following fatty acids of the bacterial cell membrane, 5-methylheptanoic acid (anteiso-C8:0) for AAA 1 -315; n-octanoic acid (n-C8:0) for AAA 2 -315; 6-methyloctanoic acid (anteiso-C9:0) for AAA 1 -329; n-nonanoic acid (n-C9:0) for AAA 2 -329; 10-methyldodecanoic acid (anteiso-C13:0) for AAA 1 -385; n-tridecanoic acid (n-C13:0) for AAA 2 -385; 11-methyltridecanoic acid (anteiso-C14:0) for AAA 1 -399; and n-tetradecanoic acid (n-C14:0) for AAA 2 -399. The concentration levels for these contaminants were estimated to be 0.1-7.9 μg / 500 mg of an individual SD L-Trp tablet or capsule The structural similarity of these homologs to case-related contaminants of Spanish Toxic Oil Syndrome (TOS) is discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

Mouse Vk gene classification by nucleic acid sequence similarity.

PubMed

Strohal, R; Helmberg, A; Kroemer, G; Kofler, R

1989-01-01

Analyses of immunoglobulin (Ig) variable (V) region gene usage in the immune response, estimates of V gene germline complexity, and other nucleic acid hybridization-based studies depend on the extent to which such genes are related (i.e., sequence similarity) and their organization in gene families. While mouse Igh heavy chain V region (VH) gene families are relatively well-established, a corresponding systematic classification of Igk light chain V region (Vk) genes has not been reported. The present analysis, in the course of which we reviewed the known extent of the Vk germline gene repertoire and Vk gene usage in a variety of responses to foreign and self antigens, provides a classification of mouse Vk genes in gene families composed of members with greater than 80% overall nucleic acid sequence similarity. This classification differed in several aspects from that of VH genes: only some Vk gene families were as clearly separated (by greater than 25% sequence dissimilarity) as typical VH gene families; most Vk gene families were closely related and, in several instances, members from different families were very similar (greater than 80%) over large sequence portions; frequently, classification by nucleic acid sequence similarity diverged from existing classifications based on amino-terminal protein sequence similarity. Our data have implications for Vk gene analyses by nucleic acid hybridization and describe potentially important differences in sequence organization between VH and Vk genes.

Combined sequence and structure analysis of the fungal laccase family.

PubMed

Kumar, S V Suresh; Phale, Prashant S; Durani, S; Wangikar, Pramod P

2003-08-20

Plant and fungal laccases belong to the family of multi-copper oxidases and show much broader substrate specificity than other members of the family. Laccases have consequently been of interest for potential industrial applications. We have analyzed the essential sequence features of fungal laccases based on multiple sequence alignments of more than 100 laccases. This has resulted in identification of a set of four ungapped sequence regions, L1-L4, as the overall signature sequences that can be used to identify the laccases, distinguishing them within the broader class of multi-copper oxidases. The 12 amino acid residues in the enzymes serving as the copper ligands are housed within these four identified conserved regions, of which L2 and L4 conform to the earlier reported copper signature sequences of multi-copper oxidases while L1 and L3 are distinctive to the laccases. The mapping of regions L1-L4 on to the three-dimensional structure of the Coprinus cinerius laccase indicates that many of the non-copper-ligating residues of the conserved regions could be critical in maintaining a specific, more or less C-2 symmetric, protein conformational motif characterizing the active site apparatus of the enzymes. The observed intraprotein homologies between L1 and L3 and between L2 and L4 at both the structure and the sequence levels suggest that the quasi C-2 symmetric active site conformational motif may have arisen from a structural duplication event that neither the sequence homology analysis nor the structure homology analysis alone would have unraveled. Although the sequence and structure homology is not detectable in the rest of the protein, the relative orientation of region L1 with L2 is similar to that of L3 with L4. The structure duplication of first-shell and second-shell residues has become cryptic because the intraprotein sequence homology noticeable for a given laccase becomes significant only after comparing the conservation pattern in several fungal

3'-terminal sequence of a small round structured virus (SRSV) in Japan.

PubMed

Utagawa, E T; Takeda, N; Inouye, S; Kasuga, K; Yamazaki, S

1994-01-01

We determined the nucleotide sequence of about 1,000 bases from the 3'-terminus of a small round structured virus (SRSV), which caused a gastroenteritis outbreak in Chiba Prefecture, Japan, in 1987. The sequence was compared with the corresponding sequence region of Norwalk virus; it consisted of a part of the open reading frame 2 (ORF2), whole ORF3, and 3'-noncoding region (NCR). The 624-base-long ORF3 had sequence homology of 68% with the corresponding region of Norwalk virus. (The amino acid sequence homology was 74%.) The 94-base-long NCR had 65% homology with Norwalk virus. We then selected two consensus-sequence portions in the above sequence between Chiba and Norwalk viruses for primers in the reverse transcriptase-polymerase chain reaction (RT-PCR). Using this primer set, we detected 669-bp bands in agarose gel electrophoresis of RT-PCR products from feces containing Chiba or Norwalk viruses. Furthermore, in Southern hybridization with Chiba probes which were labeled with digoxigenin-dUTP in PCR, the bands of the two viruses were clearly stained under a low stringency condition. Since both Chiba and Norwalk viruses were detected by the above primer set although they are geographically and chronologically different viruses, our primer-pair may be useful for detection of a broad range of SRSVs which cause gastroenteritis in different areas.

Terminal region sequence variations in variola virus DNA.

PubMed

Massung, R F; Loparev, V N; Knight, J C; Totmenin, A V; Chizhikov, V E; Parsons, J M; Safronov, P F; Gutorov, V V; Shchelkunov, S N; Esposito, J J

1996-07-15

Genome DNA terminal region sequences were determined for a Brazilian alastrim variola minor virus strain Garcia-1966 that was associated with an 0.8% case-fatality rate and African smallpox strains Congo-1970 and Somalia-1977 associated with variola major (9.6%) and minor (0.4%) mortality rates, respectively. A base sequence identity of > or = 98.8% was determined after aligning 30 kb of the left- or right-end region sequences with cognate sequences previously determined for Asian variola major strains India-1967 (31% death rate) and Bangladesh-1975 (18.5% death rate). The deduced amino acid sequences of putative proteins of > or = 65 amino acids also showed relatively high identity, although the Asian and African viruses were clearly more related to each other than to alastrim virus. Alastrim virus contained only 10 of 70 proteins that were 100% identical to homologs in Asian strains, and 7 alastrim-specific proteins were noted.

A trait stacking system via intra-genomic homologous recombination.

PubMed

Kumar, Sandeep; Worden, Andrew; Novak, Stephen; Lee, Ryan; Petolino, Joseph F

2016-11-01

A gene targeting method has been developed, which allows the conversion of 'breeding stacks', containing unlinked transgenes into a 'molecular stack' and thereby circumventing the breeding challenges associated with transgene segregation. A gene targeting method has been developed for converting two unlinked trait loci into a single locus transgene stack. The method utilizes intra-genomic homologous recombination (IGHR) between stably integrated target and donor loci which share sequence homology and nuclease cleavage sites whereby the donor contains a promoterless herbicide resistance transgene. Upon crossing with a zinc finger nuclease (ZFN)-expressing plant, double-strand breaks (DSB) are created in both the stably integrated target and donor loci. DSBs flanking the donor locus result in intra-genomic mobilization of a promoterless selectable marker-containing donor sequence, which can be utilized as a template for homology-directed repair of a concomitant DSB at the target locus resulting in a functional selectable marker via nuclease-mediated cassette exchange (NMCE). The method was successfully demonstrated in maize using a glyphosate tolerance gene as a donor whereby up to 3.3 % of the resulting progeny embryos cultured on selection medium regenerated plants with the donor sequence integrated into the target locus. The process could be extended to multiple cycles of trait stacking by virtue of a unique intron sequence homology for NMCE between the target and the donor loci. This is the first report that describes NMCE via IGHR, thereby enabling trait stacking using conventional crossing.

An Artificial Functional Family Filter in Homolog Searching in Next-generation Sequencing Metagenomics

PubMed Central

Du, Ruofei; Mercante, Donald; Fang, Zhide

2013-01-01

In functional metagenomics, BLAST homology search is a common method to classify metagenomic reads into protein/domain sequence families such as Clusters of Orthologous Groups of proteins (COGs) in order to quantify the abundance of each COG in the community. The resulting functional profile of the community is then used in downstream analysis to correlate the change in abundance to environmental perturbation, clinical variation, and so on. However, the short read length coupled with next-generation sequencing technologies poses a barrier in this approach, essentially because similarity significance cannot be discerned by searching with short reads. Consequently, artificial functional families are produced, in which those with a large number of reads assigned decreases the accuracy of functional profile dramatically. There is no method available to address this problem. We intended to fill this gap in this paper. We revealed that BLAST similarity scores of homologues for short reads from COG protein members coding sequences are distributed differently from the scores of those derived elsewhere. We showed that, by choosing an appropriate score cut-off, we are able to filter out most artificial families and simultaneously to preserve sufficient information in order to build the functional profile. We also showed that, by incorporated application of BLAST and RPS-BLAST, some artificial families with large read counts can be further identified after the score cutoff filtration. Evaluated on three experimental metagenomic datasets with different coverages, we found that the proposed method is robust against read coverage and consistently outperforms the other E-value cutoff methods currently used in literatures. PMID:23516532

Cloning and sequence analysis of complementary DNA encoding an aberrantly rearranged human T-cell gamma chain.

PubMed Central

Dialynas, D P; Murre, C; Quertermous, T; Boss, J M; Leiden, J M; Seidman, J G; Strominger, J L

1986-01-01

Complementary DNA (cDNA) encoding a human T-cell gamma chain has been cloned and sequenced. At the junction of the variable and joining regions, there is an apparent deletion of two nucleotides in the human cDNA sequence relative to the murine gamma-chain cDNA sequence, resulting simultaneously in the generation of an in-frame stop codon and in a translational frameshift. For this reason, the sequence presented here encodes an aberrantly rearranged human T-cell gamma chain. There are several surprising differences between the deduced human and murine gamma-chain amino acid sequences. These include poor homology in the variable region, poor homology in a discrete segment of the constant region precisely bounded by the expected junctions of exon CII, and the presence in the human sequence of five potential sites for N-linked glycosylation. Images PMID:3458221

A benchmark testing ground for integrating homology modeling and protein docking.

PubMed

Bohnuud, Tanggis; Luo, Lingqi; Wodak, Shoshana J; Bonvin, Alexandre M J J; Weng, Zhiping; Vajda, Sandor; Schueler-Furman, Ora; Kozakov, Dima

2017-01-01

Protein docking procedures carry out the task of predicting the structure of a protein-protein complex starting from the known structures of the individual protein components. More often than not, however, the structure of one or both components is not known, but can be derived by homology modeling on the basis of known structures of related proteins deposited in the Protein Data Bank (PDB). Thus, the problem is to develop methods that optimally integrate homology modeling and docking with the goal of predicting the structure of a complex directly from the amino acid sequences of its component proteins. One possibility is to use the best available homology modeling and docking methods. However, the models built for the individual subunits often differ to a significant degree from the bound conformation in the complex, often much more so than the differences observed between free and bound structures of the same protein, and therefore additional conformational adjustments, both at the backbone and side chain levels need to be modeled to achieve an accurate docking prediction. In particular, even homology models of overall good accuracy frequently include localized errors that unfavorably impact docking results. The predicted reliability of the different regions in the model can also serve as a useful input for the docking calculations. Here we present a benchmark dataset that should help to explore and solve combined modeling and docking problems. This dataset comprises a subset of the experimentally solved 'target' complexes from the widely used Docking Benchmark from the Weng Lab (excluding antibody-antigen complexes). This subset is extended to include the structures from the PDB related to those of the individual components of each complex, and hence represent potential templates for investigating and benchmarking integrated homology modeling and docking approaches. Template sets can be dynamically customized by specifying ranges in sequence similarity and in

Calcium-binding protein from mouse Ehrlich ascites-tumour cells is homologous to human calcyclin.

PubMed Central

Kuźnicki, J; Filipek, A; Hunziker, P E; Huber, S; Heizmann, C W

1989-01-01

A Ca2+-binding protein was purified from mouse Ehrlich ascites-tumour cells. The protein forms monomers and disulphide-linked dimers, which can be separated by reverse-phase h.p.l.c. A partial amino acid sequence analysis demonstrated that the protein has an EF-hand structure. A striking homology was found to rat and human calcyclin (a member of the S-100 protein family), which is possibly involved in cell-cycle regulation. Images Fig. 1. Fig. 2. PMID:2597136

Evidence of protein-free homology recognition in magnetic bead force-extension experiments

NASA Astrophysics Data System (ADS)

O'Lee, D. J.; Danilowicz, C.; Rochester, C.; Kornyshev, A. A.; Prentiss, M.

2016-07-01

Earlier theoretical studies have proposed that the homology-dependent pairing of large tracts of dsDNA may be due to physical interactions between homologous regions. Such interactions could contribute to the sequence-dependent pairing of chromosome regions that may occur in the presence or the absence of double-strand breaks. Several experiments have indicated the recognition of homologous sequences in pure electrolytic solutions without proteins. Here, we report single-molecule force experiments with a designed 60 kb long dsDNA construct; one end attached to a solid surface and the other end to a magnetic bead. The 60 kb constructs contain two 10 kb long homologous tracts oriented head to head, so that their sequences match if the two tracts fold on each other. The distance between the bead and the surface is measured as a function of the force applied to the bead. At low forces, the construct molecules extend substantially less than normal, control dsDNA, indicating the existence of preferential interaction between the homologous regions. The force increase causes no abrupt but continuous unfolding of the paired homologous regions. Simple semi-phenomenological models of the unfolding mechanics are proposed, and their predictions are compared with the data.

Evidence of protein-free homology recognition in magnetic bead force–extension experiments

PubMed Central

(O’) Lee, D. J.; Danilowicz, C.; Rochester, C.; Prentiss, M.

2016-01-01

Earlier theoretical studies have proposed that the homology-dependent pairing of large tracts of dsDNA may be due to physical interactions between homologous regions. Such interactions could contribute to the sequence-dependent pairing of chromosome regions that may occur in the presence or the absence of double-strand breaks. Several experiments have indicated the recognition of homologous sequences in pure electrolytic solutions without proteins. Here, we report single-molecule force experiments with a designed 60 kb long dsDNA construct; one end attached to a solid surface and the other end to a magnetic bead. The 60 kb constructs contain two 10 kb long homologous tracts oriented head to head, so that their sequences match if the two tracts fold on each other. The distance between the bead and the surface is measured as a function of the force applied to the bead. At low forces, the construct molecules extend substantially less than normal, control dsDNA, indicating the existence of preferential interaction between the homologous regions. The force increase causes no abrupt but continuous unfolding of the paired homologous regions. Simple semi-phenomenological models of the unfolding mechanics are proposed, and their predictions are compared with the data. PMID:27493568

Improve homology search sensitivity of PacBio data by correcting frameshifts.

PubMed

Du, Nan; Sun, Yanni

2016-09-01

Single-molecule, real-time sequencing (SMRT) developed by Pacific BioSciences produces longer reads than secondary generation sequencing technologies such as Illumina. The long read length enables PacBio sequencing to close gaps in genome assembly, reveal structural variations, and identify gene isoforms with higher accuracy in transcriptomic sequencing. However, PacBio data has high sequencing error rate and most of the errors are insertion or deletion errors. During alignment-based homology search, insertion or deletion errors in genes will cause frameshifts and may only lead to marginal alignment scores and short alignments. As a result, it is hard to distinguish true alignments from random alignments and the ambiguity will incur errors in structural and functional annotation. Existing frameshift correction tools are designed for data with much lower error rate and are not optimized for PacBio data. As an increasing number of groups are using SMRT, there is an urgent need for dedicated homology search tools for PacBio data. In this work, we introduce Frame-Pro, a profile homology search tool for PacBio reads. Our tool corrects sequencing errors and also outputs the profile alignments of the corrected sequences against characterized protein families. We applied our tool to both simulated and real PacBio data. The results showed that our method enables more sensitive homology search, especially for PacBio data sets of low sequencing coverage. In addition, we can correct more errors when comparing with a popular error correction tool that does not rely on hybrid sequencing. The source code is freely available at https://sourceforge.net/projects/frame-pro/ yannisun@msu.edu. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

DNA Sequence Polymorphism of the Lactate Dehydrogenase Genefrom Iranian Plasmodium vivax and Plasmodium falciparum Isolates.

PubMed

Getacher Feleke, Daniel; Nateghpour, Mehdi; Motevalli Haghi, Afsaneh; Hajjaran, Homa; Farivar, Leila; Mohebali, Mehdi; Raoofian, Reza

2015-01-01

Parasite lactate dehydrogenase (pLDH) is extensively employed as malaria rapid diagnostic tests (RDTs). Moreover, it is a well-known drug target candidate. However, the genetic diversity of this gene might influence performance of RDT kits and its drug target candidacy. This study aimed to determine polymorphism of pLDH gene from Iranian isolates of P. vivax and P. falciparum. Genomic DNA was extracted from whole blood of microscopically confirmed P. vivax and P. falciparum infected patients. pLDH gene of P. falciparum and P. vivax was amplified using conventional PCR from 43 symptomatic malaria patients from Sistan and Baluchistan Province, Southeast Iran from 2012 to 2013. Sequence analysis of 15 P. vivax LDH showed fourteen had 100% identity with P. vivax Sal-1 and Belem strains. Two nucleotide substitutions were detected with only one resulted in amino acid change. Analysis of P. falciparum LDH sequences showed six of the seven sequences had 100% homology with P. falciparum 3D7 and Mzr-1. Moreover, PfLDH displayed three nucleotide changes that resulted in changing only one amino acid. PvLDH and PfLDH showed 75%-76% nucleotide and 90.4%-90.76% amino acid homology. pLDH gene from Iranian P. falciparum and P. vivax isolates displayed 98.8-100% homology with 1-3 nucleotide substitutions. This indicated this gene was relatively conserved. Additional studies can be done weather this genetic variation can influence the performance of pLDH based RDTs or not.

Homologous prominence non-radial eruptions: A case study

NASA Astrophysics Data System (ADS)

Duchlev, P.; Koleva, K.; Madjarska, M. S.; Dechev, M.

2016-10-01

The present study provides important details on homologous eruptions of a solar prominence that occurred in active region NOAA 10904 on 2006 August 22. We report on the pre-eruptive phase of the homologous feature as well as the kinematics and the morphology of a forth from a series of prominence eruptions that is critical in defining the nature of the previous consecutive eruptions. The evolution of the overlying coronal field during homologous eruptions is discussed and a new observational criterion for homologous eruptions is provided. We find a distinctive sequence of three activation periods each of them containing pre-eruptive precursors such as a brightening and enlarging of the prominence body followed by small surge-like ejections from its southern end observed in the radio 17 GHz. We analyse a fourth eruption that clearly indicates a full reformation of the prominence after the third eruption. The fourth eruption although occurring 11 h later has an identical morphology, the same angle of propagation with respect to the radial direction, as well as similar kinematic evolution as the previous three eruptions. We find an important feature of the homologous eruptive prominence sequence that is the maximum height increase of each consecutive eruption. The present analysis establishes that all four eruptions observed in Hα are of confined type with the third eruption undergoing a thermal disappearance during its eruptive phase. We suggest that the observation of the same direction of the magnetic flux rope (MFR) ejections can be consider as an additional observational criterion for MFR homology. This observational indication for homologous eruptions is important, especially in the case of events of typical or poorly distinguishable morphology of eruptive solar phenomena.

Structural and Sequence Similarities of Hydra Xeroderma Pigmentosum A Protein to Human Homolog Suggest Early Evolution and Conservation

PubMed Central

Ghaskadbi, Saroj

2013-01-01

Xeroderma pigmentosum group A (XPA) is a protein that binds to damaged DNA, verifies presence of a lesion, and recruits other proteins of the nucleotide excision repair (NER) pathway to the site. Though its homologs from yeast, Drosophila, humans, and so forth are well studied, XPA has not so far been reported from protozoa and lower animal phyla. Hydra is a fresh-water cnidarian with a remarkable capacity for regeneration and apparent lack of organismal ageing. Cnidarians are among the first metazoa with a defined body axis, tissue grade organisation, and nervous system. We report here for the first time presence of XPA gene in hydra. Putative protein sequence of hydra XPA contains nuclear localization signal and bears the zinc-finger motif. It contains two conserved Pfam domains and various characterized features of XPA proteins like regions for binding to excision repair cross-complementing protein-1 (ERCC1) and replication protein A 70 kDa subunit (RPA70) proteins. Hydra XPA shows a high degree of similarity with vertebrate homologs and clusters with deuterostomes in phylogenetic analysis. Homology modelling corroborates the very close similarity between hydra and human XPA. The protein thus most likely functions in hydra in the same manner as in other animals, indicating that it arose early in evolution and has been conserved across animal phyla. PMID:24083246

Structural and sequence similarities of hydra xeroderma pigmentosum A protein to human homolog suggest early evolution and conservation.

PubMed

Barve, Apurva; Ghaskadbi, Saroj; Ghaskadbi, Surendra

2013-01-01

Xeroderma pigmentosum group A (XPA) is a protein that binds to damaged DNA, verifies presence of a lesion, and recruits other proteins of the nucleotide excision repair (NER) pathway to the site. Though its homologs from yeast, Drosophila, humans, and so forth are well studied, XPA has not so far been reported from protozoa and lower animal phyla. Hydra is a fresh-water cnidarian with a remarkable capacity for regeneration and apparent lack of organismal ageing. Cnidarians are among the first metazoa with a defined body axis, tissue grade organisation, and nervous system. We report here for the first time presence of XPA gene in hydra. Putative protein sequence of hydra XPA contains nuclear localization signal and bears the zinc-finger motif. It contains two conserved Pfam domains and various characterized features of XPA proteins like regions for binding to excision repair cross-complementing protein-1 (ERCC1) and replication protein A 70 kDa subunit (RPA70) proteins. Hydra XPA shows a high degree of similarity with vertebrate homologs and clusters with deuterostomes in phylogenetic analysis. Homology modelling corroborates the very close similarity between hydra and human XPA. The protein thus most likely functions in hydra in the same manner as in other animals, indicating that it arose early in evolution and has been conserved across animal phyla.

New Insight Into the Diversity of SemiSWEET Sugar Transporters and the Homologs in Prokaryotes

PubMed Central

Jia, Baolei; Hao, Lujiang; Xuan, Yuan Hu; Jeon, Che Ok

2018-01-01

Sugars will eventually be exported transporters (SWEETs) and SemiSWEETs represent a family of sugar transporters in eukaryotes and prokaryotes, respectively. SWEETs contain seven transmembrane helices (TMHs), while SemiSWEETs contain three. The functions of SemiSWEETs are less studied. In this perspective article, we analyzed the diversity and conservation of SemiSWEETs and further proposed the possible functions. 1,922 SemiSWEET homologs were retrieved from the UniProt database, which is not proportional to the sequenced prokaryotic genomes. However, these proteins are very diverse in sequences and can be classified into 19 clusters when >50% sequence identity is required. Moreover, a gene context analysis indicated that several SemiSWEETs are located in the operons that are related to diverse carbohydrate metabolism. Several proteins with seven TMHs can be found in bacteria, and sequence alignment suggested that these proteins in bacteria may be formed by the duplication and fusion. Multiple sequence alignments showed that the amino acids for sugar translocation are still conserved and coevolved, although the sequences show diversity. Among them, the functions of a few amino acids are still not clear. These findings highlight the challenges that exist in SemiSWEETs and provide future researchers the foundation to explore these uncharted areas. PMID:29872447

New Insight Into the Diversity of SemiSWEET Sugar Transporters and the Homologs in Prokaryotes.

PubMed

Jia, Baolei; Hao, Lujiang; Xuan, Yuan Hu; Jeon, Che Ok

2018-01-01

Sugars will eventually be exported transporters (SWEETs) and SemiSWEETs represent a family of sugar transporters in eukaryotes and prokaryotes, respectively. SWEETs contain seven transmembrane helices (TMHs), while SemiSWEETs contain three. The functions of SemiSWEETs are less studied. In this perspective article, we analyzed the diversity and conservation of SemiSWEETs and further proposed the possible functions. 1,922 SemiSWEET homologs were retrieved from the UniProt database, which is not proportional to the sequenced prokaryotic genomes. However, these proteins are very diverse in sequences and can be classified into 19 clusters when >50% sequence identity is required. Moreover, a gene context analysis indicated that several SemiSWEETs are located in the operons that are related to diverse carbohydrate metabolism. Several proteins with seven TMHs can be found in bacteria, and sequence alignment suggested that these proteins in bacteria may be formed by the duplication and fusion. Multiple sequence alignments showed that the amino acids for sugar translocation are still conserved and coevolved, although the sequences show diversity. Among them, the functions of a few amino acids are still not clear. These findings highlight the challenges that exist in SemiSWEETs and provide future researchers the foundation to explore these uncharted areas.

RNABindRPlus: a predictor that combines machine learning and sequence homology-based methods to improve the reliability of predicted RNA-binding residues in proteins.

PubMed

Walia, Rasna R; Xue, Li C; Wilkins, Katherine; El-Manzalawy, Yasser; Dobbs, Drena; Honavar, Vasant

2014-01-01

Protein-RNA interactions are central to essential cellular processes such as protein synthesis and regulation of gene expression and play roles in human infectious and genetic diseases. Reliable identification of protein-RNA interfaces is critical for understanding the structural bases and functional implications of such interactions and for developing effective approaches to rational drug design. Sequence-based computational methods offer a viable, cost-effective way to identify putative RNA-binding residues in RNA-binding proteins. Here we report two novel approaches: (i) HomPRIP, a sequence homology-based method for predicting RNA-binding sites in proteins; (ii) RNABindRPlus, a new method that combines predictions from HomPRIP with those from an optimized Support Vector Machine (SVM) classifier trained on a benchmark dataset of 198 RNA-binding proteins. Although highly reliable, HomPRIP cannot make predictions for the unaligned parts of query proteins and its coverage is limited by the availability of close sequence homologs of the query protein with experimentally determined RNA-binding sites. RNABindRPlus overcomes these limitations. We compared the performance of HomPRIP and RNABindRPlus with that of several state-of-the-art predictors on two test sets, RB44 and RB111. On a subset of proteins for which homologs with experimentally determined interfaces could be reliably identified, HomPRIP outperformed all other methods achieving an MCC of 0.63 on RB44 and 0.83 on RB111. RNABindRPlus was able to predict RNA-binding residues of all proteins in both test sets, achieving an MCC of 0.55 and 0.37, respectively, and outperforming all other methods, including those that make use of structure-derived features of proteins. More importantly, RNABindRPlus outperforms all other methods for any choice of tradeoff between precision and recall. An important advantage of both HomPRIP and RNABindRPlus is that they rely on readily available sequence and sequence

An aureobasidin A resistance gene isolated from Aspergillus is a homolog of yeast AUR1, a gene responsible for inositol phosphorylceramide (IPC) synthase activity.

PubMed

Kuroda, M; Hashida-Okado, T; Yasumoto, R; Gomi, K; Kato, I; Takesako, K

1999-03-01

The AUR1 gene of Saccharomyces cerevisiae, mutations in which confer resistance to the antibiotic aureobasidin A, is necessary for inositol phosphorylceramide (IPC) synthase activity. We report the molecular cloning and characterization of the Aspergillus nidulans aurA gene, which is homologous to AUR1. A single point mutation in the aurA gene of A. nidulans confers a high level of resistance to aureobasidin A. The A. nidulans aurA gene was used to identify its homologs in other Aspergillus species, including A. fumigatus, A. niger, and A. oryzae. The deduced amino acid sequence of an aurA homolog from the pathogenic fungus A. fumigatus showed 87% identity to that of A. nidulans. The AurA proteins of A. nidulans and A. fumigatus shared common characteristics in primary structure, including sequence, hydropathy profile, and N-glycosylation sites, with their S. cerevisiae, Schizosaccharomyces pombe, and Candida albicans counterparts. These results suggest that the aureobasidin resistance gene is conserved evolutionarily in various fungi.

Mitochondrial Genome Sequence of the Legume Vicia faba

PubMed Central

Negruk, Valentine

2013-01-01

The number of plant mitochondrial genomes sequenced exceeds two dozen. However, for a detailed comparative study of different phylogenetic branches more plant mitochondrial genomes should be sequenced. This article presents sequencing data and comparative analysis of mitochondrial DNA (mtDNA) of the legume Vicia faba. The size of the V. faba circular mitochondrial master chromosome of cultivar Broad Windsor was estimated as 588,000 bp with a genome complexity of 387,745 bp and 52 conservative mitochondrial genes; 32 of them encoding proteins, 3 rRNA, and 17 tRNA genes. Six tRNA genes were highly homologous to chloroplast genome sequences. In addition to the 52 conservative genes, 114 unique open reading frames (ORFs) were found, 36 without significant homology to any known proteins and 29 with homology to the Medicago truncatula nuclear genome and to other plant mitochondrial ORFs, 49 ORFs were not homologous to M. truncatula but possessed sequences with significant homology to other plant mitochondrial or nuclear ORFs. In general, the unique ORFs revealed very low homology to known closely related legumes, but several sequence homologies were found between V. faba, Beta vulgaris, Nicotiana tabacum, Vitis vinifera, and even the monocots Oryza sativa and Zea mays. Most likely these ORFs arose independently during angiosperm evolution (Kubo and Mikami, 2007; Kubo and Newton, 2008). Computational analysis revealed in total about 45% of V. faba mtDNA sequence being homologous to the Medicago truncatula nuclear genome (more than to any sequenced plant mitochondrial genome), and 35% of this homology ranging from a few dozen to 12,806 bp are located on chromosome 1. Apparently, mitochondrial rrn5, rrn18, rps10, ATP synthase subunit alpha, cox2, and tRNA sequences are part of transcribed nuclear mosaic ORFs. PMID:23675376

Caught in the act: the lifetime of synaptic intermediates during the search for homology on DNA

PubMed Central

Mani, Adam; Braslavsky, Ido; Arbel-Goren, Rinat; Stavans, Joel

2010-01-01

Homologous recombination plays pivotal roles in DNA repair and in the generation of genetic diversity. To locate homologous target sequences at which strand exchange can occur within a timescale that a cell’s biology demands, a single-stranded DNA-recombinase complex must search among a large number of sequences on a genome by forming synapses with chromosomal segments of DNA. A key element in the search is the time it takes for the two sequences of DNA to be compared, i.e. the synapse lifetime. Here, we visualize for the first time fluorescently tagged individual synapses formed by RecA, a prokaryotic recombinase, and measure their lifetime as a function of synapse length and differences in sequence between the participating DNAs. Surprisingly, lifetimes can be ∼10 s long when the DNAs are fully heterologous, and much longer for partial homology, consistently with ensemble FRET measurements. Synapse lifetime increases rapidly as the length of a region of full homology at either the 3′- or 5′-ends of the invading single-stranded DNA increases above 30 bases. A few mismatches can reduce dramatically the lifetime of synapses formed with nearly homologous DNAs. These results suggest the need for facilitated homology search mechanisms to locate homology successfully within the timescales observed in vivo. PMID:20044347

Phylo-mLogo: an interactive and hierarchical multiple-logo visualization tool for alignment of many sequences

PubMed Central

Shih, Arthur Chun-Chieh; Lee, DT; Peng, Chin-Lin; Wu, Yu-Wei

2007-01-01

Background When aligning several hundreds or thousands of sequences, such as epidemic virus sequences or homologous/orthologous sequences of some big gene families, to reconstruct the epidemiological history or their phylogenies, how to analyze and visualize the alignment results of many sequences has become a new challenge for computational biologists. Although there are several tools available for visualization of very long sequence alignments, few of them are applicable to the alignments of many sequences. Results A multiple-logo alignment visualization tool, called Phylo-mLogo, is presented in this paper. Phylo-mLogo calculates the variabilities and homogeneities of alignment sequences by base frequencies or entropies. Different from the traditional representations of sequence logos, Phylo-mLogo not only displays the global logo patterns of the whole alignment of multiple sequences, but also demonstrates their local homologous logos for each clade hierarchically. In addition, Phylo-mLogo also allows the user to focus only on the analysis of some important, structurally or functionally constrained sites in the alignment selected by the user or by built-in automatic calculation. Conclusion With Phylo-mLogo, the user can symbolically and hierarchically visualize hundreds of aligned sequences simultaneously and easily check the changes of their amino acid sites when analyzing many homologous/orthologous or influenza virus sequences. More information of Phylo-mLogo can be found at URL . PMID:17319966

The amino acid sequence of Staphylococcus aureus penicillinase.

PubMed Central

Ambler, R P

1975-01-01

The amino acid sequence of the penicillinase (penicillin amido-beta-lactamhydrolase, EC 3.5.2.6) from Staphylococcus aureus strain PC1 was determined. The protein consists of a single polypeptide chain of 257 residues, and the sequence was determined by characterization of tryptic, chymotryptic, peptic and CNBr peptides, with some additional evidence from thermolysin and S. aureus proteinase peptides. A mistake in the preliminary report of the sequence is corrected; residues 113-116 are now thought to be -Lys-Lys-Val-Lys- rather than -Lys-Val-Lys-Lys-. Detailed evidence for the amino acid sequence has been deposited as Supplementary Publication SUP 50056 (91 pages) at the British Library (Lending Division), Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1975) 145, 5. PMID:1218078

Nucleotide sequences of two genomic DNAs encoding peroxidase of Arabidopsis thaliana.

PubMed

Intapruk, C; Higashimura, N; Yamamoto, K; Okada, N; Shinmyo, A; Takano, M

1991-02-15

The peroxidase (EC 1.11.1.7)-encoding gene of Arabidopsis thaliana was screened from a genomic library using a cDNA encoding a neutral isozyme of horseradish, Armoracia rusticana, peroxidase (HRP) as a probe, and two positive clones were isolated. From the comparison with the sequences of the HRP-encoding genes, we concluded that two clones contained peroxidase-encoding genes, and they were named prxCa and prxEa. Both genes consisted of four exons and three introns; the introns had consensus nucleotides, GT and AG, at the 5' and 3' ends, respectively. The lengths of each putative exon of the prxEa gene were the same as those of the HRP-basic-isozyme-encoding gene, prxC3, and coded for 349 amino acids (aa) with a sequence homology of 89% to that encoded by prxC3. The prxCa gene was very close to the HRP-neutral-isozyme-encoding gene, prxC1b, and coded for 354 aa with 91% homology to that encoded by prxC1b. The aa sequence homology was 64% between the two peroxidases encoded by prxCa and prxEa.

Homology analysis and cross-immunogenicity of OmpA from pathogenic Yersinia enterocolitica, Yersinia pseudotuberculosis and Yersinia pestis.

PubMed

Chen, Yuhuang; Duan, Ran; Li, Xu; Li, Kewei; Liang, Junrong; Liu, Chang; Qiu, Haiyan; Xiao, Yuchun; Jing, Huaiqi; Wang, Xin

2015-12-01

The outer membrane protein A (OmpA) is one of the intra-species conserved proteins with immunogenicity widely found in the family of Enterobacteriaceae. Here we first confirmed OmpA is conserved in the three pathogenic Yersinia: Yersinia pestis, Yersinia pseudotuberculosis and pathogenic Yersinia enterocolitica, with high homology at the nucleotide level and at the amino acid sequence level. The identity of ompA sequences for 262 Y. pestis strains, 134 Y. pseudotuberculosis strains and 219 pathogenic Y. enterocolitica strains are 100%, 98.8% and 97.7% similar. The main pattern of OmpA of pathogenic Yersinia are 86.2% and 88.8% identical at the nucleotide and amino acid sequence levels, respectively. Immunological analysis showed the immunogenicity of each OmpA and cross-immunogenicity of OmpA for pathogenic Yersinia where OmpA may be a vaccine candidate for Y. pestis and other pathogenic Yersinia. Copyright © 2015 Elsevier Ltd. All rights reserved.

SANSparallel: interactive homology search against Uniprot

PubMed Central

Somervuo, Panu; Holm, Liisa

2015-01-01

Proteins evolve by mutations and natural selection. The network of sequence similarities is a rich source for mining homologous relationships that inform on protein structure and function. There are many servers available to browse the network of homology relationships but one has to wait up to a minute for results. The SANSparallel webserver provides protein sequence database searches with immediate response and professional alignment visualization by third-party software. The output is a list, pairwise alignment or stacked alignment of sequence-similar proteins from Uniprot, UniRef90/50, Swissprot or Protein Data Bank. The stacked alignments are viewed in Jalview or as sequence logos. The database search uses the suffix array neighborhood search (SANS) method, which has been re-implemented as a client-server, improved and parallelized. The method is extremely fast and as sensitive as BLAST above 50% sequence identity. Benchmarks show that the method is highly competitive compared to previously published fast database search programs: UBLAST, DIAMOND, LAST, LAMBDA, RAPSEARCH2 and BLAT. The web server can be accessed interactively or programmatically at http://ekhidna2.biocenter.helsinki.fi/cgi-bin/sans/sans.cgi. It can be used to make protein functional annotation pipelines more efficient, and it is useful in interactive exploration of the detailed evidence supporting the annotation of particular proteins of interest. PMID:25855811

Using distances between Top-n-gram and residue pairs for protein remote homology detection.

PubMed

Liu, Bin; Xu, Jinghao; Zou, Quan; Xu, Ruifeng; Wang, Xiaolong; Chen, Qingcai

2014-01-01

Protein remote homology detection is one of the central problems in bioinformatics, which is important for both basic research and practical application. Currently, discriminative methods based on Support Vector Machines (SVMs) achieve the state-of-the-art performance. Exploring feature vectors incorporating the position information of amino acids or other protein building blocks is a key step to improve the performance of the SVM-based methods. Two new methods for protein remote homology detection were proposed, called SVM-DR and SVM-DT. SVM-DR is a sequence-based method, in which the feature vector representation for protein is based on the distances between residue pairs. SVM-DT is a profile-based method, which considers the distances between Top-n-gram pairs. Top-n-gram can be viewed as a profile-based building block of proteins, which is calculated from the frequency profiles. These two methods are position dependent approaches incorporating the sequence-order information of protein sequences. Various experiments were conducted on a benchmark dataset containing 54 families and 23 superfamilies. Experimental results showed that these two new methods are very promising. Compared with the position independent methods, the performance improvement is obvious. Furthermore, the proposed methods can also provide useful insights for studying the features of protein families. The better performance of the proposed methods demonstrates that the position dependant approaches are efficient for protein remote homology detection. Another advantage of our methods arises from the explicit feature space representation, which can be used to analyze the characteristic features of protein families. The source code of SVM-DT and SVM-DR is available at http://bioinformatics.hitsz.edu.cn/DistanceSVM/index.jsp.

Two amino acid residues confer different binding affinities of Abelson family kinase SRC homology 2 domains for phosphorylated cortactin.

PubMed

Gifford, Stacey M; Liu, Weizhi; Mader, Christopher C; Halo, Tiffany L; Machida, Kazuya; Boggon, Titus J; Koleske, Anthony J

2014-07-11

The closely related Abl family kinases, Arg and Abl, play important non-redundant roles in the regulation of cell morphogenesis and motility. Despite similar N-terminal sequences, Arg and Abl interact with different substrates and binding partners with varying affinities. This selectivity may be due to slight differences in amino acid sequence leading to differential interactions with target proteins. We report that the Arg Src homology (SH) 2 domain binds two specific phosphotyrosines on cortactin, a known Abl/Arg substrate, with over 10-fold higher affinity than the Abl SH2 domain. We show that this significant affinity difference is due to the substitution of arginine 161 and serine 187 in Abl to leucine 207 and threonine 233 in Arg, respectively. We constructed Abl SH2 domains with R161L and S187T mutations alone and in combination and find that these substitutions are sufficient to convert the low affinity Abl SH2 domain to a higher affinity "Arg-like" SH2 domain in binding to a phospho-cortactin peptide. We crystallized the Arg SH2 domain for structural comparison to existing crystal structures of the Abl SH2 domain. We show that these two residues are important determinants of Arg and Abl SH2 domain binding specificity. Finally, we expressed Arg containing an "Abl-like" low affinity mutant Arg SH2 domain (L207R/T233S) and find that this mutant, although properly localized to the cell periphery, does not support wild type levels of cell edge protrusion. Together, these observations indicate that these two amino acid positions confer different binding affinities and cellular functions on the distinct Abl family kinases. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Induction of homologous recombination in Saccharomyces cerevisiae.

PubMed

Simon, J R; Moore, P D

1988-09-01

We have investigated the effects of UV irradiation of Saccharomyces cerevisiae in order to distinguish whether UV-induced recombination results from the induction of enzymes required for homologous recombination, or the production of substrate sites for recombination containing regions of DNA damage. We utilized split-dose experiments to investigate the induction of proteins required for survival, gene conversion, and mutation in a diploid strain of S. cerevisiae. We demonstrate that inducing doses of UV irradiation followed by a 6 h period of incubation render the cells resistant to challenge doses of UV irradiation. The effects of inducing and challenge doses of UV irradiation upon interchromosomal gene conversion and mutation are strictly additive. Using the yeast URA3 gene cloned in non-replicating single- and double-stranded plasmid vectors that integrate into chromosomal genes upon transformation, we show that UV irradiation of haploid yeast cells and homologous plasmid DNA sequences each stimulate homologous recombination approximately two-fold, and that these effects are additive. Non-specific DNA damage has little effect on the stimulation of homologous recombination, as shown by studies in which UV-irradiated heterologous DNA was included in transformation/recombination experiments. We further demonstrate that the effect of competing single- and double-stranded heterologous DNA sequences differs in UV-irradiated and unirradiated cells, suggesting an induction of recombinational machinery in UV-irradiated S. cerevisiae cells.

orthoFind Facilitates the Discovery of Homologous and Orthologous Proteins.

PubMed

Mier, Pablo; Andrade-Navarro, Miguel A; Pérez-Pulido, Antonio J

2015-01-01

Finding homologous and orthologous protein sequences is often the first step in evolutionary studies, annotation projects, and experiments of functional complementation. Despite all currently available computational tools, there is a requirement for easy-to-use tools that provide functional information. Here, a new web application called orthoFind is presented, which allows a quick search for homologous and orthologous proteins given one or more query sequences, allowing a recurrent and exhaustive search against reference proteomes, and being able to include user databases. It addresses the protein multidomain problem, searching for homologs with the same domain architecture, and gives a simple functional analysis of the results to help in the annotation process. orthoFind is easy to use and has been proven to provide accurate results with different datasets. Availability: http://www.bioinfocabd.upo.es/orthofind/.

The semaphorontic view of homology.

PubMed

Havstad, Joyce C; Assis, Leandro C S; Rieppel, Olivier

2015-11-01

The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra-organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter-species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity--ontogenetic (through development) and phylogenetic (via shared evolutionary history)--break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (-state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (-states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution Published by Wiley Periodicals, Inc.

Detection and isolation of nucleic acid sequences using competitive hybridization probes

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

1997-01-01

A method for detecting a target nucleic acid sequence in a sample is provided using hybridization probes which competitively hybridize to a target nucleic acid. According to the method, a target nucleic acid sequence is hybridized to first and second hybridization probes which are complementary to overlapping portions of the target nucleic acid sequence, the first hybridization probe including a first complexing agent capable of forming a binding pair with a second complexing agent and the second hybridization probe including a detectable marker. The first complexing agent attached to the first hybridization probe is contacted with a second complexing agent, the second complexing agent being attached to a solid support such that when the first and second complexing agents are attached, target nucleic acid sequences hybridized to the first hybridization probe become immobilized on to the solid support. The immobilized target nucleic acids are then separated and detected by detecting the detectable marker attached to the second hybridization probe. A kit for performing the method is also provided.

Detection and isolation of nucleic acid sequences using competitive hybridization probes

DOEpatents

Lucas, J.N.; Straume, T.; Bogen, K.T.

1997-04-01

A method for detecting a target nucleic acid sequence in a sample is provided using hybridization probes which competitively hybridize to a target nucleic acid. According to the method, a target nucleic acid sequence is hybridized to first and second hybridization probes which are complementary to overlapping portions of the target nucleic acid sequence, the first hybridization probe including a first complexing agent capable of forming a binding pair with a second complexing agent and the second hybridization probe including a detectable marker. The first complexing agent attached to the first hybridization probe is contacted with a second complexing agent, the second complexing agent being attached to a solid support such that when the first and second complexing agents are attached, target nucleic acid sequences hybridized to the first hybridization probe become immobilized on to the solid support. The immobilized target nucleic acids are then separated and detected by detecting the detectable marker attached to the second hybridization probe. A kit for performing the method is also provided. 7 figs.

Human homolog of the mouse sperm receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chamberlin, M.E.; Dean, J.

1990-08-01

The human zona pellucida, composed of three glycoproteins (ZP1, ZP2, and ZP3), forms an extracellular matrix that surrounds ovulated eggs and mediates species-specific fertilization. The genes that code for at least two of the zona proteins (ZP2 and ZP3) cross-hybridize with other mammalian DNA. The recently characterized mouse sperm receptor gene (Zp-3) was used to isolate its human homolog. The human homolog spans {approx}18.3 kilobase pairs (kbp) (compared to 8.6 kbp for the mouse gene) and contains eight exons, the sizes of which are strictly conserved between the two species. Four short (8-15 bp) sequences within the first 250 bpmore » of the 5{prime} flanking region in the human Zp-3 homolog are also present upstream of mouse Zp-3. These elements may modulate oocyte-specific gene expression. By using the polymerase chain reaction, a full-length cDNA of human ZP3 was isolated from human ovarian poly(A){sup +} RNA and used to deduce the structure of human ZP3 mRNA. Certain features of the human and mouse ZP3 transcripts are conserved. Both have unusually short 5{prime} and 3{prime} untranslated regions, both contain a single open reading frame that is 74% identical, and both code for 424 amino acid polypeptides that are 67% the same. The similarity between the two proteins may define domains that are important in maintaining the structural integrity of the zona pellucida, while the differences may play a role in mediating the species-specific events of mammalian fertilization.« less

Tumor malignancy is engaged to prokaryotic homolog toolbox.

PubMed

Fernandes, Janaina; Guedes, Patrícia G; Lage, Celso Luiz S; Rodrigues, Juliany Cola F; Lage, Claudia de Alencar S

2012-04-01

Cancer cells display high proliferation rates and survival provided by high glycolysis, chemoresistance and radioresistance, metabolic features that appear to be activated with malignancy, and seemed to have arisen as early in evolution as in unicellular/prokaryotic organisms. Based on these assumptions, we hypothesize that aggressive phenotypes found in malignant cells may be related to acquired unicellular behavior, launched within a tumor when viral and prokaryotic homologs are overexpressed performing likely robust functions. The ensemble of these expressed viral and prokaryotic close homologs in the proteome of a tumor tissue gives them advantage over normal cells. To assess the hypothesis validity, sequences of human proteins involved in apoptosis, energetic metabolism, cell mobility and adhesion, chemo- and radio-resistance were aligned to homologs present in other life forms, excluding all eukaryotes, using PSI-BLAST, with further corroboration from data available in the literature. The analysis revealed that selected sequences of proteins involved in apoptosis and tumor suppression (as p53 and pRB) scored non-significant (E-value>0.001) with prokaryotic homologs; on the other hand, human proteins involved in cellular chemo- and radio-resistance scored highly significant with prokaryotic and viral homologs (as catalase, E-value=zero). We inferred that such upregulated and/or functionally activated proteins in aggressive malignant cells represent a toolbox of modern human homologs evolved from a similar key set that have granted survival of ancient prokaryotes against extremely harsh environments. According to what has been discussed along this analysis, high mutation rates usually hit hotspots in important conserved protein domains, allowing uncontrolled expansion of more resistant, death-evading malignant clones. That is the case of point mutations in key viral proteins affording viruses escape to chemotherapy, and human homologs of such retroviral

Porcine parvovirus: DNA sequence and genome organization.

PubMed

Ranz, A I; Manclús, J J; Díaz-Aroca, E; Casal, J I

1989-10-01

We have determined the nucleotide sequence of an almost full-length clone of porcine parvovirus (PPV). The sequence is 4973 nucleotides (nt) long. The 3' end of virion DNA shows a Y-shaped configuration homologous to rodent parvoviruses. The 5' end of virion DNA shows a repetition of 127 nt at the carboxy terminus of the capsid proteins. The overall organization of the PPV genome is similar to those of other autonomous parvoviruses. There are two large open reading frames (ORFs) that almost entirely cover the genome, both located in the same frame of the complementary strand. The left ORF encodes the non-structural protein NS1 and the right ORF encodes the capsid proteins (VP1, VP2 and VP3). Promoter analysis, location of splicing sites and putative amino acid sequences for the viral proteins show a high homology of PPV with feline panleukopenia virus and canine parvoviruses (FPV and CPV) and rodent parvovirus. Therefore we conclude that PPV is related to the Kilham rat virus (KRV) group of autonomous parvoviruses formed by KRV, minute virus of mice, Lu III, H-1, FPV and CPV.

Sequence divergence of the red and green visual pigments in great apes and humans.

PubMed Central

Deeb, S S; Jorgensen, A L; Battisti, L; Iwasaki, L; Motulsky, A G

1994-01-01

We have determined the coding sequences of red and green visual pigment genes of the chimpanzee, gorilla, and orangutan. The deduced amino acid sequences of these pigments are highly homologous to the equivalent human pigments. None of the amino acid differences occurred at sites that were previously shown to influence pigment absorption characteristics. Therefore, we predict the spectra of red and green pigments of the apes to have wavelengths of maximum absorption that differ by < 2 nm from the equivalent human pigments and that color vision in these nonhuman primates will be very similar, if not identical, to that in humans. A total of 14 within-species polymorphisms (6 involving silent substitutions) were observed in the coding sequences of the red and green pigment genes of the great apes. Remarkably, the polymorphisms at 6 of these sites had been observed in human populations, suggesting that they predated the evolution of higher primates. Alleles at polymorphic sites were often shared between the red and green pigment genes. The average synonymous rate of divergence of red from green sequences was approximately 1/10th that estimated for other proteins of higher primates, indicating the involvement of gene conversion in generating these polymorphisms. The high degree of homology and juxtaposition of these two genes on the X chromosome has promoted unequal recombination and/or gene conversion that led to sequence homogenization. However, natural selection operated to maintain the degree of separation in peak absorbance between the red and green pigments that resulted in optimal chromatic discrimination. This represents a unique case of molecular coevolution between two homologous genes that functionally interact at the behavioral level. PMID:8041777

Characterization and Nucleotide Sequence of CARB-6, a New Carbenicillin-Hydrolyzing β-Lactamase from Vibrio cholerae

PubMed Central

Choury, Danièle; Aubert, Gérald; Szajnert, Marie-France; Azibi, Kemal; Delpech, Marc; Paul, Gérard

1999-01-01

A clinical strain of Vibrio cholerae non-O1 non-O139 isolated in France produced a new β-lactamase with a pI of 5.35. The purified enzyme, with a molecular mass of 33,000 Da, was characterized. Its kinetic constants show it to be a carbenicillin-hydrolyzing enzyme comparable to the five previously reported CARB β-lactamases and to SAR-1, another carbenicillin-hydrolyzing β-lactamase that has a pI of 4.9 and that is produced by a V. cholerae strain from Tanzania. This β-lactamase is designated CARB-6, and the gene for CARB-6 could not be transferred to Escherichia coli K-12 by conjugation. The nucleotide sequence of the structural gene was determined by direct sequencing of PCR-generated fragments from plasmid DNA with four pairs of primers covering the whole sequence of the reference CARB-3 gene. The gene encodes a 288-amino-acid protein that shares 94% homology with the CARB-1, CARB-2, and CARB-3 enzymes, 93% homology with the Proteus mirabilis N29 enzyme, and 86.5% homology with the CARB-4 enzyme. The sequence of CARB-6 differs from those of CARB-3, CARB-2, CARB-1, N29, and CARB-4 at 15, 16, 17, 19, and 37 amino acid positions, respectively. All these mutations are located in the C-terminal region of the sequence and at the surface of the molecule, according to the crystal structure of the Staphylococcus aureus PC-1 β-lactamase. PMID:9925522

Streptomyces griseus streptomycin phosphotransferase: expression of its gene in Escherichia coli and sequence homology with other antibiotic phosphotransferases and with eukaryotic protein kinases.

PubMed

Lim, C K; Smith, M C; Petty, J; Baumberg, S; Wootton, J C

1989-12-01

The aphD gene of Streptomyces griseus, encoding a streptomycin 6-phosphotransferase (SPH), was sub-cloned in the pBR322-based expression vector pRK9 (which contains the Serratia marcescens trp promoter) with selection for expression of streptomycin resistance in Escherichia coli. Two hybrid plasmids, pCKL631 and pCKL711, were isolated which conferred resistance. Both contained a approximately 2 kbp fragment already suspected to include aphD. The properties of in vitro deletion derivatives of these plasmids were consistent with the presumed location of aphD. In vitro deletion of a sequence including most of the trp promoter largely, but not quite completely, abolished the ability of the plasmid to confer streptomycin resistance, confirming that expression was indeed principally from the trp promoter. A polypeptide of approximately 34.5 kDa was present in minicells containing plasmids that conferred streptomycin resistance, but was absent when the plasmids contained in vitro deletions removing streptomycin resistance. Part of the fragment was sequenced and an open reading frame corresponding to aphD identified. A computer-assisted comparison of the deduced SPH sequence with those of other antibiotic phosphotransferases suggested a common structure A-B-C-D-E, where B and D were conserved between all sequences compared while A, C and E divided between the streptomycin and hygromycin B phosphotransferases on one hand and kanamycin/neomycin ones on the other. A composite sequence data base was searched for homologues to consensus matrices constructed from five approximately 12-residue subsequences within blocks B and D. For one subsequence, corresponding to the N-terminal portion of block D, those sequences from the database that yielded the highest homology scores comprised almost entirely either antibiotic phosphotransferases or eukaryotic protein kinases. Possible evolutionary implications of this homology, previously described by other groups, are discussed.

Phenolic acid esterases, coding sequences and methods

DOEpatents

Blum, David L.; Kataeva, Irina; Li, Xin-Liang; Ljungdahl, Lars G.

2002-01-01

Described herein are four phenolic acid esterases, three of which correspond to domains of previously unknown function within bacterial xylanases, from XynY and XynZ of Clostridium thermocellum and from a xylanase of Ruminococcus. The fourth specifically exemplified xylanase is a protein encoded within the genome of Orpinomyces PC-2. The amino acids of these polypeptides and nucleotide sequences encoding them are provided. Recombinant host cells, expression vectors and methods for the recombinant production of phenolic acid esterases are also provided.

Identification of random nucleic acid sequence aberrations using dual capture probes which hybridize to different chromosome regions

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

1998-01-01

A method is provided for detecting nucleic acid sequence aberrations using two immobilization steps. According to the method, a nucleic acid sequence aberration is detected by detecting nucleic acid sequences having both a first nucleic acid sequence type (e.g., from a first chromosome) and a second nucleic acid sequence type (e.g., from a second chromosome), the presence of the first and the second nucleic acid sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. In the method, immobilization of a first hybridization probe is used to isolate a first set of nucleic acids in the sample which contain the first nucleic acid sequence type. Immobilization of a second hybridization probe is then used to isolate a second set of nucleic acids from within the first set of nucleic acids which contain the second nucleic acid sequence type. The second set of nucleic acids are then detected, their presence indicating the presence of a nucleic acid sequence aberration.

The semaphorontic view of homology

PubMed Central

Assis, Leandro C.S.; Rieppel, Olivier

2015-01-01

ABSTRACT The relation of homology is generally characterized as an identity relation, or alternatively as a correspondence relation, both of which are transitive. We use the example of the ontogenetic development and evolutionary origin of the gnathostome jaw to discuss identity and transitivity of the homology relation under the transformationist and emergentist paradigms respectively. Token identity and consequent transitivity of homology relations are shown to be requirements that are too strong to allow the origin of genuine evolutionary novelties. We consequently introduce the concept of compositional identity that is grounded in relations prevailing between parts (organs and organ systems) of a whole (organism). We recognize an ontogenetic identity of parts within a whole throughout the sequence of successive developmental stages of those parts: this is an intra‐organismal character identity maintained throughout developmental trajectory. Correspondingly, we recognize a phylogenetic identity of homologous parts within two or more organisms of different species: this is an inter‐species character identity maintained throughout evolutionary trajectory. These different dimensions of character identity—ontogenetic (through development) and phylogenetic (via shared evolutionary history)—break the transitivity of homology relations. Under the transformationist paradigm, the relation of homology reigns over the entire character (‐state) transformation series, and thus encompasses the plesiomorphic as well as the apomorphic condition of form. In contrast, genuine evolutionary novelties originate not through transformation of ancestral characters (‐states), but instead through deviating developmental trajectories that result in alternate characters. Under the emergentist paradigm, homology is thus synonymous with synapomorphy. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 578–587, 2015. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and

Identification of random nucleic acid sequence aberrations using dual capture probes which hybridize to different chromosome regions

DOEpatents

Lucas, J.N.; Straume, T.; Bogen, K.T.

1998-03-24

A method is provided for detecting nucleic acid sequence aberrations using two immobilization steps. According to the method, a nucleic acid sequence aberration is detected by detecting nucleic acid sequences having both a first nucleic acid sequence type (e.g., from a first chromosome) and a second nucleic acid sequence type (e.g., from a second chromosome), the presence of the first and the second nucleic acid sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. In the method, immobilization of a first hybridization probe is used to isolate a first set of nucleic acids in the sample which contain the first nucleic acid sequence type. Immobilization of a second hybridization probe is then used to isolate a second set of nucleic acids from within the first set of nucleic acids which contain the second nucleic acid sequence type. The second set of nucleic acids are then detected, their presence indicating the presence of a nucleic acid sequence aberration. 14 figs.

Homology modeling of Homo sapiens lipoic acid synthase: Substrate docking and insights on its binding mode.

PubMed

Krishnamoorthy, Ezhilarasi; Hassan, Sameer; Hanna, Luke Elizabeth; Padmalayam, Indira; Rajaram, Rama; Viswanathan, Vijay

2017-05-07

Lipoic acid synthase (LIAS) is an iron-sulfur cluster mitochondrial enzyme which catalyzes the final step in the de novo pathway for the biosynthesis of lipoic acid, a potent antioxidant. Recently there has been significant interest in its role in metabolic diseases and its deficiency in LIAS expression has been linked to conditions such as diabetes, atherosclerosis and neonatal-onset epilepsy, suggesting a strong inverse correlation between LIAS reduction and disease status. In this study we use a bioinformatics approach to predict its structure, which would be helpful to understanding its role. A homology model for LIAS protein was generated using X-ray crystallographic structure of Thermosynechococcus elongatus BP-1 (PDB ID: 4U0P). The predicted structure has 93% of the residues in the most favour region of Ramachandran plot. The active site of LIAS protein was mapped and docked with S-Adenosyl Methionine (SAM) using GOLD software. The LIAS-SAM complex was further refined using molecular dynamics simulation within the subsite 1 and subsite 3 of the active site. To the best of our knowledge, this is the first study to report a reliable homology model of LIAS protein. This study will facilitate a better understanding mode of action of the enzyme-substrate complex for future studies in designing drugs that can target LIAS protein. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nucleic and Amino Acid Sequences Support Structure-Based Viral Classification.

PubMed

Sinclair, Robert M; Ravantti, Janne J; Bamford, Dennis H

2017-04-15

Viral capsids ensure viral genome integrity by protecting the enclosed nucleic acids. Interactions between the genome and capsid and between individual capsid proteins (i.e., capsid architecture) are intimate and are expected to be characterized by strong evolutionary conservation. For this reason, a capsid structure-based viral classification has been proposed as a way to bring order to the viral universe. The seeming lack of sufficient sequence similarity to reproduce this classification has made it difficult to reject structural convergence as the basis for the classification. We reinvestigate whether the structure-based classification for viral coat proteins making icosahedral virus capsids is in fact supported by previously undetected sequence similarity. Since codon choices can influence nascent protein folding cotranslationally, we searched for both amino acid and nucleotide sequence similarity. To demonstrate the sensitivity of the approach, we identify a candidate gene for the pandoravirus capsid protein. We show that the structure-based classification is strongly supported by amino acid and also nucleotide sequence similarities, suggesting that the similarities are due to common descent. The correspondence between structure-based and sequence-based analyses of the same proteins shown here allow them to be used in future analyses of the relationship between linear sequence information and macromolecular function, as well as between linear sequence and protein folds. IMPORTANCE Viral capsids protect nucleic acid genomes, which in turn encode capsid proteins. This tight coupling of protein shell and nucleic acids, together with strong functional constraints on capsid protein folding and architecture, leads to the hypothesis that capsid protein-coding nucleotide sequences may retain signatures of ancient viral evolution. We have been able to show that this is indeed the case, using the major capsid proteins of viruses forming icosahedral capsids. Importantly

Nucleic and Amino Acid Sequences Support Structure-Based Viral Classification

PubMed Central

Sinclair, Robert M.; Ravantti, Janne J.

2017-01-01

ABSTRACT Viral capsids ensure viral genome integrity by protecting the enclosed nucleic acids. Interactions between the genome and capsid and between individual capsid proteins (i.e., capsid architecture) are intimate and are expected to be characterized by strong evolutionary conservation. For this reason, a capsid structure-based viral classification has been proposed as a way to bring order to the viral universe. The seeming lack of sufficient sequence similarity to reproduce this classification has made it difficult to reject structural convergence as the basis for the classification. We reinvestigate whether the structure-based classification for viral coat proteins making icosahedral virus capsids is in fact supported by previously undetected sequence similarity. Since codon choices can influence nascent protein folding cotranslationally, we searched for both amino acid and nucleotide sequence similarity. To demonstrate the sensitivity of the approach, we identify a candidate gene for the pandoravirus capsid protein. We show that the structure-based classification is strongly supported by amino acid and also nucleotide sequence similarities, suggesting that the similarities are due to common descent. The correspondence between structure-based and sequence-based analyses of the same proteins shown here allow them to be used in future analyses of the relationship between linear sequence information and macromolecular function, as well as between linear sequence and protein folds. IMPORTANCE Viral capsids protect nucleic acid genomes, which in turn encode capsid proteins. This tight coupling of protein shell and nucleic acids, together with strong functional constraints on capsid protein folding and architecture, leads to the hypothesis that capsid protein-coding nucleotide sequences may retain signatures of ancient viral evolution. We have been able to show that this is indeed the case, using the major capsid proteins of viruses forming icosahedral capsids

Overcoming Sequence Misalignments with Weighted Structural Superposition

PubMed Central

Khazanov, Nickolay A.; Damm-Ganamet, Kelly L.; Quang, Daniel X.; Carlson, Heather A.

2012-01-01

An appropriate structural superposition identifies similarities and differences between homologous proteins that are not evident from sequence alignments alone. We have coupled our Gaussian-weighted RMSD (wRMSD) tool with a sequence aligner and seed extension (SE) algorithm to create a robust technique for overlaying structures and aligning sequences of homologous proteins (HwRMSD). HwRMSD overcomes errors in the initial sequence alignment that would normally propagate into a standard RMSD overlay. SE can generate a corrected sequence alignment from the improved structural superposition obtained by wRMSD. HwRMSD’s robust performance and its superiority over standard RMSD are demonstrated over a range of homologous proteins. Its better overlay results in corrected sequence alignments with good agreement to HOMSTRAD. Finally, HwRMSD is compared to established structural alignment methods: FATCAT, SSM, CE, and Dalilite. Most methods are comparable at placing residue pairs within 2 Å, but HwRMSD places many more residue pairs within 1 Å, providing a clear advantage. Such high accuracy is essential in drug design, where small distances can have a large impact on computational predictions. This level of accuracy is also needed to correct sequence alignments in an automated fashion, especially for omics-scale analysis. HwRMSD can align homologs with low sequence identity and large conformational differences, cases where both sequence-based and structural-based methods may fail. The HwRMSD pipeline overcomes the dependency of structural overlays on initial sequence pairing and removes the need to determine the best sequence-alignment method, substitution matrix, and gap parameters for each unique pair of homologs. PMID:22733542

The limits of protein sequence comparison?

PubMed Central

Pearson, William R; Sierk, Michael L

2010-01-01

Modern sequence alignment algorithms are used routinely to identify homologous proteins, proteins that share a common ancestor. Homologous proteins always share similar structures and often have similar functions. Over the past 20 years, sequence comparison has become both more sensitive, largely because of profile-based methods, and more reliable, because of more accurate statistical estimates. As sequence and structure databases become larger, and comparison methods become more powerful, reliable statistical estimates will become even more important for distinguishing similarities that are due to homology from those that are due to analogy (convergence). The newest sequence alignment methods are more sensitive than older methods, but more accurate statistical estimates are needed for their full power to be realized. PMID:15919194

Homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8

PubMed Central

Garba, Lawal; Mohamad Yussoff, Mohamad Ariff; Abd Halim, Khairul Bariyyah; Ishak, Siti Nor Hasmah; Mohamad Ali, Mohd Shukuri; Oslan, Siti Nurbaya

2018-01-01

Membrane-bound fatty acid desaturases perform oxygenated desaturation reactions to insert double bonds within fatty acyl chains in regioselective and stereoselective manners. The Δ9-fatty acid desaturase strictly creates the first double bond between C9 and 10 positions of most saturated substrates. As the three-dimensional structures of the bacterial membrane fatty acid desaturases are not available, relevant information about the enzymes are derived from their amino acid sequences, site-directed mutagenesis and domain swapping in similar membrane-bound desaturases. The cold-tolerant Pseudomonas sp. AMS8 was found to produce high amount of monounsaturated fatty acids at low temperature. Subsequently, an active Δ9-fatty acid desaturase was isolated and functionally expressed in Escherichia coli. In this paper we report homology modeling and docking studies of a Δ9-fatty acid desaturase from a Cold-tolerant Pseudomonas sp. AMS8 for the first time to the best of our knowledge. Three dimensional structure of the enzyme was built using MODELLER version 9.18 using a suitable template. The protein model contained the three conserved-histidine residues typical for all membrane-bound desaturase catalytic activity. The structure was subjected to energy minimization and checked for correctness using Ramachandran plots and ERRAT, which showed a good quality model of 91.6 and 65.0%, respectively. The protein model was used to preform MD simulation and docking of palmitic acid using CHARMM36 force field in GROMACS Version 5 and Autodock tool Version 4.2, respectively. The docking simulation with the lowest binding energy, −6.8 kcal/mol had a number of residues in close contact with the docked palmitic acid namely, Ile26, Tyr95, Val179, Gly180, Pro64, Glu203, His34, His206, His71, Arg182, Thr85, Lys98 and His177. Interestingly, among the binding residues are His34, His71 and His206 from the first, second, and third conserved histidine motif, respectively, which constitute

Sequence similarities and evolutionary relationships of microbial, plant and animal alpha-amylases.

PubMed

Janecek, S

1994-09-01

Amino acid sequence comparison of 37 alpha-amylases from microbial, plant and animal sources was performed to identify their mutual sequence similarities in addition to the five already described conserved regions. These sequence regions were examined from structure/function and evolutionary perspectives. An unrooted evolutionary tree of alpha-amylases was constructed on a subset of 55 residues from the alignment of sequence similarities along with conserved regions. The most important new information extracted from the tree was as follows: (a) the close evolutionary relationship of Alteromonas haloplanctis alpha-amylase (thermolabile enzyme from an antarctic psychrotroph) with the already known group of homologous alpha-amylases from streptomycetes, Thermomonospora curvata, insects and mammals, and (b) the remarkable 40.1% identity between starch-saccharifying Bacillus subtilis alpha-amylase and the enzyme from the ruminal bacterium Butyrivibrio fibrisolvens, an alpha-amylase with an unusually large polypeptide chain (943 residues in the mature enzyme). Due to a very high degree of similarity, the whole amino acid sequences of three groups of alpha-amylases, namely (a) fungi and yeasts, (b) plants, and (c) A. haloplanctis, streptomycetes, T. curvata, insects and mammals, were aligned independently and their unrooted distance trees were calculated using these alignments. Possible rooting of the trees was also discussed. Based on the knowledge of the location of the five disulfide bonds in the structure of pig pancreatic alpha-amylase, the possible disulfide bridges were established for each of these groups of homologous alpha-amylases.

Lion (Panthera leo) and cheetah (Acinonyx jubatus) IFN-gamma sequences.

PubMed

Maas, Miriam; Van Rhijn, Ildiko; Allsopp, Maria T E P; Rutten, Victor P M G

2010-04-15

Cloning and sequencing of the full length lion and cheetah interferon-gamma (IFN-gamma) transcript will enable the expression of the recombinant cytokine, to be used for production of monoclonal antibodies and to set up lion and cheetah-specific IFN-gamma ELISAs. These are relevant in blood-based diagnosis of bovine tuberculosis, an important threat to lions in the Kruger National Park. Alignment of nucleotide and amino acid sequences of lion and cheetah and that of domestic cats showed homologies of 97-100%. Copyright 2009 Elsevier B.V. All rights reserved.

Homology groups for particles on one-connected graphs

NASA Astrophysics Data System (ADS)

MaciÄ Żek, Tomasz; Sawicki, Adam

2017-06-01

We present a mathematical framework for describing the topology of configuration spaces for particles on one-connected graphs. In particular, we compute the homology groups over integers for different classes of one-connected graphs. Our approach is based on some fundamental combinatorial properties of the configuration spaces, Mayer-Vietoris sequences for different parts of configuration spaces, and some limited use of discrete Morse theory. As one of the results, we derive the closed-form formulae for ranks of the homology groups for indistinguishable particles on tree graphs. We also give a detailed discussion of the second homology group of the configuration space of both distinguishable and indistinguishable particles. Our motivation is the search for new kinds of quantum statistics.

Comparative sequence analysis of a region on human chromosome 13q14, frequently deleted in B-cell chronic lymphocytic leukemia, and its homologous region on mouse chromosome 14.

PubMed

Kapanadze, B; Makeeva, N; Corcoran, M; Jareborg, N; Hammarsund, M; Baranova, A; Zabarovsky, E; Vorontsova, O; Merup, M; Gahrton, G; Jansson, M; Yankovsky, N; Einhorn, S; Oscier, D; Grandér, D; Sangfelt, O

2000-12-15

Previous studies have indicated the presence of a putative tumor suppressor gene on human chromosome 13q14, commonly deleted in patients with B-cell chronic lymphocytic leukemia (B-CLL). We have recently identified a minimally deleted region encompassing parts of two adjacent genes, termed LEU1 and LEU2 (leukemia-associated genes 1 and 2), and several additional transcripts. In addition, 50 kb centromeric to this region we have identified another gene, LEU5/RFP2. To elucidate further the complex genomic organization of this region, we have identified, mapped, and sequenced the homologous region in the mouse. Fluorescence in situ hybridization analysis demonstrated that the region maps to mouse chromosome 14. The overall organization and gene order in this region were found to be highly conserved in the mouse. Sequence comparison between the human deletion hotspot region and its homologous mouse region revealed a high degree of sequence conservation with an overall score of 74%. However, our data also show that in terms of transcribed sequences, only two of those, human LEU2 and LEU5/RFP2, are clearly conserved, strengthening the case for these genes as putative candidate B-CLL tumor suppressor genes.

Cyclic azole-homologated peptides from Marine sponges.

PubMed

Molinski, Tadeusz F

2017-12-19

This review discusses the chemistry of cyclic azole-homologated peptides (AHPs) from the marine sponges, Theonella swinhoei, other Theonella species, Calyx spp. and Plakina jamaicensis. The origin, distribution of AHPs and molecular structure elucidations of AHPs are described followed by their biosynthesis, bioactivity, and synthetic efforts towards their total synthesis. Reports of partial and total synthesis of AHPs extend beyond peptide coupling reactions and include creative construction of the non-proteinogenic amino acid components, mainly the homologated heteroaromatic and α-keto-β-amino acids. A useful conclusion is drawn regarding AHPs: despite their rarity, exotic structures and the potent protease inhibitory properties of some members, their synthesis is under-developed and beckons solutions for outstanding problems towards their efficient assembly.

Clustering evolving proteins into homologous families.

PubMed

Chan, Cheong Xin; Mahbob, Maisarah; Ragan, Mark A

2013-04-08

Clustering sequences into groups of putative homologs (families) is a critical first step in many areas of comparative biology and bioinformatics. The performance of clustering approaches in delineating biologically meaningful families depends strongly on characteristics of the data, including content bias and degree of divergence. New, highly scalable methods have recently been introduced to cluster the very large datasets being generated by next-generation sequencing technologies. However, there has been little systematic investigation of how characteristics of the data impact the performance of these approaches. Using clusters from a manually curated dataset as reference, we examined the performance of a widely used graph-based Markov clustering algorithm (MCL) and a greedy heuristic approach (UCLUST) in delineating protein families coded by three sets of bacterial genomes of different G+C content. Both MCL and UCLUST generated clusters that are comparable to the reference sets at specific parameter settings, although UCLUST tends to under-cluster compositionally biased sequences (G+C content 33% and 66%). Using simulated data, we sought to assess the individual effects of sequence divergence, rate heterogeneity, and underlying G+C content. Performance decreased with increasing sequence divergence, decreasing among-site rate variation, and increasing G+C bias. Two MCL-based methods recovered the simulated families more accurately than did UCLUST. MCL using local alignment distances is more robust across the investigated range of sequence features than are greedy heuristics using distances based on global alignment. Our results demonstrate that sequence divergence, rate heterogeneity and content bias can individually and in combination affect the accuracy with which MCL and UCLUST can recover homologous protein families. For application to data that are more divergent, and exhibit higher among-site rate variation and/or content bias, MCL may often be the better

Ancient DNA sequence revealed by error-correcting codes.

PubMed

Brandão, Marcelo M; Spoladore, Larissa; Faria, Luzinete C B; Rocha, Andréa S L; Silva-Filho, Marcio C; Palazzo, Reginaldo

2015-07-10

A previously described DNA sequence generator algorithm (DNA-SGA) using error-correcting codes has been employed as a computational tool to address the evolutionary pathway of the genetic code. The code-generated sequence alignment demonstrated that a residue mutation revealed by the code can be found in the same position in sequences of distantly related taxa. Furthermore, the code-generated sequences do not promote amino acid changes in the deviant genomes through codon reassignment. A Bayesian evolutionary analysis of both code-generated and homologous sequences of the Arabidopsis thaliana malate dehydrogenase gene indicates an approximately 1 MYA divergence time from the MDH code-generated sequence node to its paralogous sequences. The DNA-SGA helps to determine the plesiomorphic state of DNA sequences because a single nucleotide alteration often occurs in distantly related taxa and can be found in the alternative codon patterns of noncanonical genetic codes. As a consequence, the algorithm may reveal an earlier stage of the evolution of the standard code.

Ancient DNA sequence revealed by error-correcting codes

PubMed Central

Brandão, Marcelo M.; Spoladore, Larissa; Faria, Luzinete C. B.; Rocha, Andréa S. L.; Silva-Filho, Marcio C.; Palazzo, Reginaldo

2015-01-01

A previously described DNA sequence generator algorithm (DNA-SGA) using error-correcting codes has been employed as a computational tool to address the evolutionary pathway of the genetic code. The code-generated sequence alignment demonstrated that a residue mutation revealed by the code can be found in the same position in sequences of distantly related taxa. Furthermore, the code-generated sequences do not promote amino acid changes in the deviant genomes through codon reassignment. A Bayesian evolutionary analysis of both code-generated and homologous sequences of the Arabidopsis thaliana malate dehydrogenase gene indicates an approximately 1 MYA divergence time from the MDH code-generated sequence node to its paralogous sequences. The DNA-SGA helps to determine the plesiomorphic state of DNA sequences because a single nucleotide alteration often occurs in distantly related taxa and can be found in the alternative codon patterns of noncanonical genetic codes. As a consequence, the algorithm may reveal an earlier stage of the evolution of the standard code. PMID:26159228

The site-specific ribosomal insertion element type II of Bombyx mori (R2Bm) contains the coding sequence for a reverse transcriptase-like enzyme.

PubMed Central

Burke, W D; Calalang, C C; Eickbush, T H

1987-01-01

Two classes of DNA elements interrupt a fraction of the rRNA repeats of Bombyx mori. We have analyzed by genomic blotting and sequence analysis one class of these elements which we have named R2. These elements occupy approximately 9% of the rDNA units of B. mori and appear to be homologous to the type II rDNA insertions detected in Drosophila melanogaster. Approximately 25 copies of R2 exist within the B. mori genome, of which at least 20 are located at a precise location within otherwise typical rDNA units. Nucleotide sequence analysis has revealed that the 4.2-kilobase-pair R2 element has a single large open reading frame, occupying over 82% of the total length of the element. The central region of this 1,151-amino-acid open reading frame shows homology to the reverse transcriptase enzymes found in retroviruses and certain transposable elements. Amino acid homology of this region is highest to the mobile line 1 elements of mammals, followed by the mitochondrial type II introns of fungi, and the pol gene of retroviruses. Less homology exists with transposable elements of D. melanogaster and Saccharomyces cerevisiae. Two additional regions of sequence homology between L1 and R2 elements were also found outside the reverse transcriptase region. We suggest that the R2 elements are retrotransposons that are site specific in their insertion into the genome. Such mobility would enable these elements to occupy a small fraction of the rDNA units of B. mori despite their continual elimination from the rDNA locus by sequence turnover. Images PMID:2439905

Primary structure of rat cardiac beta-adrenergic and muscarinic cholinergic receptors obtained by automated DNA sequence analysis: further evidence for a multigene family.

PubMed Central

Gocayne, J; Robinson, D A; FitzGerald, M G; Chung, F Z; Kerlavage, A R; Lentes, K U; Lai, J; Wang, C D; Fraser, C M; Venter, J C

1987-01-01

Two cDNA clones, lambda RHM-MF and lambda RHB-DAR, encoding the muscarinic cholinergic receptor and the beta-adrenergic receptor, respectively, have been isolated from a rat heart cDNA library. The cDNA clones were characterized by restriction mapping and automated DNA sequence analysis utilizing fluorescent dye primers. The rat heart muscarinic receptor consists of 466 amino acids and has a calculated molecular weight of 51,543. The rat heart beta-adrenergic receptor consists of 418 amino acids and has a calculated molecular weight of 46,890. The two cardiac receptors have substantial amino acid homology (27.2% identity, 50.6% with favored substitutions). The rat cardiac beta receptor has 88.0% homology (92.5% with favored substitutions) with the human brain beta receptor and the rat cardiac muscarinic receptor has 94.6% homology (97.6% with favored substitutions) with the porcine cardiac muscarinic receptor. The muscarinic cholinergic and beta-adrenergic receptors appear to be as conserved as hemoglobin and cytochrome c but less conserved than histones and are clearly members of a multigene family. These data support our hypothesis, based upon biochemical and immunological evidence, that suggests considerable structural homology and evolutionary conservation between adrenergic and muscarinic cholinergic receptors. To our knowledge, this is the first report utilizing automated DNA sequence analysis to determine the structure of a gene. Images PMID:2825184

Primary structure of rat cardiac beta-adrenergic and muscarinic cholinergic receptors obtained by automated DNA sequence analysis: further evidence for a multigene family.

PubMed

Gocayne, J; Robinson, D A; FitzGerald, M G; Chung, F Z; Kerlavage, A R; Lentes, K U; Lai, J; Wang, C D; Fraser, C M; Venter, J C

1987-12-01

Two cDNA clones, lambda RHM-MF and lambda RHB-DAR, encoding the muscarinic cholinergic receptor and the beta-adrenergic receptor, respectively, have been isolated from a rat heart cDNA library. The cDNA clones were characterized by restriction mapping and automated DNA sequence analysis utilizing fluorescent dye primers. The rat heart muscarinic receptor consists of 466 amino acids and has a calculated molecular weight of 51,543. The rat heart beta-adrenergic receptor consists of 418 amino acids and has a calculated molecular weight of 46,890. The two cardiac receptors have substantial amino acid homology (27.2% identity, 50.6% with favored substitutions). The rat cardiac beta receptor has 88.0% homology (92.5% with favored substitutions) with the human brain beta receptor and the rat cardiac muscarinic receptor has 94.6% homology (97.6% with favored substitutions) with the porcine cardiac muscarinic receptor. The muscarinic cholinergic and beta-adrenergic receptors appear to be as conserved as hemoglobin and cytochrome c but less conserved than histones and are clearly members of a multigene family. These data support our hypothesis, based upon biochemical and immunological evidence, that suggests considerable structural homology and evolutionary conservation between adrenergic and muscarinic cholinergic receptors. To our knowledge, this is the first report utilizing automated DNA sequence analysis to determine the structure of a gene.

The catalytic chain of human complement subcomponent C1r. Purification and N-terminal amino acid sequences of the major cyanogen bromide-cleavage fragments.

PubMed

Arlaud, G J; Gagnon, J; Porter, R R

1982-01-01

1. The a- and b-chains of reduced and alkylated human complement subcomponent C1r were separated by high-pressure gel-permeation chromatography and isolated in good yield and in pure form. 2. CNBr cleavage of C1r b-chain yielded eight major peptides, which were purified by gel filtration and high-pressure reversed-phase chromatography. As determined from the sum of their amino acid compositions, these peptides accounted for a minimum molecular weight of 28 000, close to the value 29 100 calculated from the whole b-chain. 3. N-Terminal sequence determinations of C1r b-chain and its CNBr-cleavage peptides allowed the identification of about two-thirds of the amino acids of C1r b-chain. From our results, and on the basis of homology with other serine proteinases, an alignment of the eight CNBr-cleavage peptides from C1r b-chain is proposed. 4. The residues forming the 'charge-relay' system of the active site of serine proteinases (His-57, Asp-102 and Ser-195 in the chymotrypsinogen numbering) are found in the corresponding regions of C1r b-chain, and the amino acid sequence around these residues has been determined. 5. The N-terminal sequence of C1r b-chain has been extended to residue 60 and reveals that C1r b-chain lacks the 'histidine loop', a disulphide bond that is present in all other known serine proteinases.

Conservation of coevolving protein interfaces bridges prokaryote–eukaryote homologies in the twilight zone

PubMed Central

Rodriguez-Rivas, Juan; Marsili, Simone; Juan, David; Valencia, Alfonso

2016-01-01

Protein–protein interactions are fundamental for the proper functioning of the cell. As a result, protein interaction surfaces are subject to strong evolutionary constraints. Recent developments have shown that residue coevolution provides accurate predictions of heterodimeric protein interfaces from sequence information. So far these approaches have been limited to the analysis of families of prokaryotic complexes for which large multiple sequence alignments of homologous sequences can be compiled. We explore the hypothesis that coevolution points to structurally conserved contacts at protein–protein interfaces, which can be reliably projected to homologous complexes with distantly related sequences. We introduce a domain-centered protocol to study the interplay between residue coevolution and structural conservation of protein–protein interfaces. We show that sequence-based coevolutionary analysis systematically identifies residue contacts at prokaryotic interfaces that are structurally conserved at the interface of their eukaryotic counterparts. In turn, this allows the prediction of conserved contacts at eukaryotic protein–protein interfaces with high confidence using solely mutational patterns extracted from prokaryotic genomes. Even in the context of high divergence in sequence (the twilight zone), where standard homology modeling of protein complexes is unreliable, our approach provides sequence-based accurate information about specific details of protein interactions at the residue level. Selected examples of the application of prokaryotic coevolutionary analysis to the prediction of eukaryotic interfaces further illustrate the potential of this approach. PMID:27965389

Conservation of coevolving protein interfaces bridges prokaryote-eukaryote homologies in the twilight zone.

PubMed

Rodriguez-Rivas, Juan; Marsili, Simone; Juan, David; Valencia, Alfonso

2016-12-27

Protein-protein interactions are fundamental for the proper functioning of the cell. As a result, protein interaction surfaces are subject to strong evolutionary constraints. Recent developments have shown that residue coevolution provides accurate predictions of heterodimeric protein interfaces from sequence information. So far these approaches have been limited to the analysis of families of prokaryotic complexes for which large multiple sequence alignments of homologous sequences can be compiled. We explore the hypothesis that coevolution points to structurally conserved contacts at protein-protein interfaces, which can be reliably projected to homologous complexes with distantly related sequences. We introduce a domain-centered protocol to study the interplay between residue coevolution and structural conservation of protein-protein interfaces. We show that sequence-based coevolutionary analysis systematically identifies residue contacts at prokaryotic interfaces that are structurally conserved at the interface of their eukaryotic counterparts. In turn, this allows the prediction of conserved contacts at eukaryotic protein-protein interfaces with high confidence using solely mutational patterns extracted from prokaryotic genomes. Even in the context of high divergence in sequence (the twilight zone), where standard homology modeling of protein complexes is unreliable, our approach provides sequence-based accurate information about specific details of protein interactions at the residue level. Selected examples of the application of prokaryotic coevolutionary analysis to the prediction of eukaryotic interfaces further illustrate the potential of this approach.

Homology of pendrin, sodium-iodide symporter and apical iodide transporter.

PubMed

Benvenga, Salvatore; Guarneri, Fabrizio

2018-06-01

We observed local homology between human pendrin and sodium/iodide symporter (NIS), that was absent in the NIS-homologous sodium/monocarboxylate transporter or apical iodide transporter (AIT) which, however, does not transport iodide. Thus, we analyzed the full proteins. They shared 63 identical and 66 similar residues (overall homology 14.4%, but 21% when omitting intervening sequences of 15 or more residues). Pendrin was more homologous to NIS (25%) than AIT (20%), particularly in the STAS domain (sulfate transporter and antisigma factor antagonist). Homology was concentrated in 11 segments, with 3/11 involving the STAS domain. In 9/11, homology was greater with NIS (45-58.3%) than with AIT (8.3-42.3%); in 4 of these 9 segments, homology was comparable to or greater than that between NIS and AIT (8.3-52.6%). Pendrin residues which are mutated in Pendred's syndrome are identical to those in the aligned position of NIS and AIT. Hypothyroidism-associated pendrin mutations almost always fall within 4/11 segments. These are the first data that show homology between pendrin and NIS, and topographic relationships between pendrin mutations and the hypothyroid phenotype of PDS.

New steroid 5alpha-reductase type I (SRD5A1) homologous sequences on human chromosomes 6 and 8.

PubMed

Eminović, I; Liović, M; Prezelj, J; Kocijancic, A; Rozman, D; Komel, R

2001-01-01

To date, two genes encoding 5alpha-reductase isoenzymes are known (type I, type II), and one type I pseudogene. The divergent localization of these genes and the still not fully understood function of the encoded enzymes as well as the perplexing results we obtained after sequencing PCR-amplified SRD5A1 gene fragments (out of genomic DNA), made us assume that, in addition to the known SRD5A1 gene, one or more different human 5alpha-reductase type I coding genes may exist. Our research provide the first evidence for the existence of two new SRD5A1 related, previously unidentified sequences in the human genome. These sequences which were localized to chromosomes 6 and 8 are highly homologous (> 99%) to SRD5A1, and also do not contain any deletions or insertions that are otherwise a characteristic of the SRD5API pseudogene. Our results imply that these sequences may be either coding parts of yet unknown, active SRD5A1 genes, and/or of previously unidentified pseudogenes. These findings additionally support data of Chen et al. who confirmed the existence of various SRD5A1 proteins in cultured human skin cells.

Nucleic acid sequence detection using multiplexed oligonucleotide PCR

DOEpatents

Nolan, John P [Santa Fe, NM; White, P Scott [Los Alamos, NM

2006-12-26

Methods for rapidly detecting single or multiple sequence alleles in a sample nucleic acid are described. Provided are all of the oligonucleotide pairs capable of annealing specifically to a target allele and discriminating among possible sequences thereof, and ligating to each other to form an oligonucleotide complex when a particular sequence feature is present (or, alternatively, absent) in the sample nucleic acid. The design of each oligonucleotide pair permits the subsequent high-level PCR amplification of a specific amplicon when the oligonucleotide complex is formed, but not when the oligonucleotide complex is not formed. The presence or absence of the specific amplicon is used to detect the allele. Detection of the specific amplicon may be achieved using a variety of methods well known in the art, including without limitation, oligonucleotide capture onto DNA chips or microarrays, oligonucleotide capture onto beads or microspheres, electrophoresis, and mass spectrometry. Various labels and address-capture tags may be employed in the amplicon detection step of multiplexed assays, as further described herein.

Cloning of Giardia lamblia heat shock protein HSP70 homologs: implications regarding origin of eukaryotic cells and of endoplasmic reticulum.

PubMed Central

Gupta, R S; Aitken, K; Falah, M; Singh, B

1994-01-01

The genes for two different 70-kDa heat shock protein (HSP70) homologs have been cloned and sequenced from the protozoan Giardia lamblia. On the basis of their sequence features, one of these genes corresponds to the cytoplasmic form of HSP70. The second gene, on the basis of its characteristic N-terminal hydrophobic signal sequence and C-terminal endoplasmic reticulum (ER) retention sequence (Lys-Asp-Glu-Leu), is the equivalent of ER-resident GRP78 or the Bip family of proteins. Phylogenetic trees based on HSP70 sequences show that G. lamblia homologs show the deepest divergence among eukaryotic species. The identification of a GRP78 or Bip homolog in G. lamblia strongly suggests the existence of ER in this ancient eukaryote. Detailed phylogenetic analyses of HSP70 sequences by boot-strap neighbor-joining and maximum-parsimony methods show that the cytoplasmic and ER homologs form distinct subfamilies that evolved from a common eukaryotic ancestor by gene duplication that occurred very early in the evolution of eukaryotic cells. It is postulated that because of the essential "molecular chaperone" function of these proteins in translocation of other proteins across membranes, duplication of their genes accompanied the evolution of ER or nucleus in the eukaryotic cell ancestor. The presence in all eukaryotic cytoplasmic HSP70 homologs (including the cognate, heat-induced, and ER forms) of a number of autapomorphic sequence signatures that are not present in any prokaryotic or organellar homologs provides strong evidence regarding the monophyletic nature of eukaryotic lineage. Further, all eukaryotic HSP70 homologs share in common with the Gram-negative group of eubacteria a number of sequence features that are not present in any archaebacterium or Gram-positive bacterium, indicating their evolution from this group of organisms. Some implications of these findings regarding the evolution of eukaryotic cells and ER are discussed. Images PMID:8159675

The cDNA sequence of mouse Pgp-1 and homology to human CD44 cell surface antigen and proteoglycan core/link proteins.

PubMed

Wolffe, E J; Gause, W C; Pelfrey, C M; Holland, S M; Steinberg, A D; August, J T

1990-01-05

We describe the isolation and sequencing of a cDNA encoding mouse Pgp-1. An oligonucleotide probe corresponding to the NH2-terminal sequence of the purified protein was synthesized by the polymerase chain reaction and used to screen a mouse macrophage lambda gt11 library. A cDNA clone with an insert of 1.2 kilobases was selected and sequenced. In Northern blot analysis, only cells expressing Pgp-1 contained mRNA species that hybridized with this Pgp-1 cDNA. The nucleotide sequence of the cDNA has a single open reading frame that yields a protein-coding sequence of 1076 base pairs followed by a 132-base pair 3'-untranslated sequence that includes a putative polyadenylation signal but no poly(A) tail. The translated sequence comprises a 13-amino acid signal peptide followed by a polypeptide core of 345 residues corresponding to an Mr of 37,800. Portions of the deduced amino acid sequence were identical to those obtained by amino acid sequence analysis from the purified glycoprotein, confirming that the cDNA encodes Pgp-1. The predicted structure of Pgp-1 includes an NH2-terminal extracellular domain (residues 14-265), a transmembrane domain (residues 266-286), and a cytoplasmic tail (residues 287-358). Portions of the mouse Pgp-1 sequence are highly similar to that of the human CD44 cell surface glycoprotein implicated in cell adhesion. The protein also shows sequence similarity to the proteoglycan tandem repeat sequences found in cartilage link protein and cartilage proteoglycan core protein which are thought to be involved in binding to hyaluronic acid.

Seq2Logo: a method for construction and visualization of amino acid binding motifs and sequence profiles including sequence weighting, pseudo counts and two-sided representation of amino acid enrichment and depletion

PubMed Central

Thomsen, Martin Christen Frølund; Nielsen, Morten

2012-01-01

Seq2Logo is a web-based sequence logo generator. Sequence logos are a graphical representation of the information content stored in a multiple sequence alignment (MSA) and provide a compact and highly intuitive representation of the position-specific amino acid composition of binding motifs, active sites, etc. in biological sequences. Accurate generation of sequence logos is often compromised by sequence redundancy and low number of observations. Moreover, most methods available for sequence logo generation focus on displaying the position-specific enrichment of amino acids, discarding the equally valuable information related to amino acid depletion. Seq2logo aims at resolving these issues allowing the user to include sequence weighting to correct for data redundancy, pseudo counts to correct for low number of observations and different logotype representations each capturing different aspects related to amino acid enrichment and depletion. Besides allowing input in the format of peptides and MSA, Seq2Logo accepts input as Blast sequence profiles, providing easy access for non-expert end-users to characterize and identify functionally conserved/variable amino acids in any given protein of interest. The output from the server is a sequence logo and a PSSM. Seq2Logo is available at http://www.cbs.dtu.dk/biotools/Seq2Logo (14 May 2012, date last accessed). PMID:22638583

Sequence of the fhuE outer-membrane receptor gene of Escherichia coli K12 and properties of mutants.

PubMed

Sauer, M; Hantke, K; Braun, V

1990-03-01

The fhuE gene of Escherichia coli codes for an outer-membrane receptor protein required for the uptake of iron(III) via coprogen, ferrioxamine B and rhodotorulic acid. The amino acid sequence, deduced from the nucleotide sequence, consisted of 729 residues. The mature form, composed of 693 residues, has a calculated molecular weight of 77,453, which agrees with the molecular weight of 76,000 determined by polyacrylamide gel electrophoresis. The FhuE protein contains four regions of homology with other TonB-dependent receptors. A valine to proline exchange in the 'TonB box' abolished transport activity. Phenotypic revertants with substitutions of arginine, glutamine, or leucine at the valine position exhibited increasing iron-coprogen transport rates. Point mutations resulting in the replacement of glycine (127) in the second homology region with either alanine, aspartate, valine, asparagine or histidine exhibited decreased transport rates (listed in descending order). A truncated FhuE protein lacking 24 amino acids at the C-terminal end was exported to the periplasm but failed to be inserted into the outer membrane.

Hydrophobic cluster analysis of G protein-coupled receptors: a powerful tool to derive structural and functional information from 2D-representation of protein sequences.

PubMed

Lentes, K U; Mathieu, E; Bischoff, R; Rasmussen, U B; Pavirani, A

1993-01-01

Current methods for comparative analyses of protein sequences are 1D-alignments of amino acid sequences based on the maximization of amino acid identity (homology) and the prediction of secondary structure elements. This method has a major drawback once the amino acid identity drops below 20-25%, since maximization of a homology score does not take into account any structural information. A new technique called Hydrophobic Cluster Analysis (HCA) has been developed by Lemesle-Varloot et al. (Biochimie 72, 555-574), 1990). This consists of comparing several sequences simultaneously and combining homology detection with secondary structure analysis. HCA is primarily based on the detection and comparison of structural segments constituting the hydrophobic core of globular protein domains, with or without transmembrane domains. We have applied HCA to the analysis of different families of G-protein coupled receptors, such as catecholamine receptors as well as peptide hormone receptors. Utilizing HCA the thrombin receptor, a new and as yet unique member of the family of G-protein coupled receptors, can be clearly classified as being closely related to the family of neuropeptide receptors rather than to the catecholamine receptors for which the shape of the hydrophobic clusters and the length of their third cytoplasmic loop are very different. Furthermore, the potential of HCA to predict relationships between new putative and already characterized members of this family of receptors will be presented.

New acute transforming feline retovirus with fms homology specifies a C-terminally truncated version of the c-fms protein that is different from SM-feline sarcoma virus v-fms protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Besmer, P.; Lader, E.; George, P.C.

1986-10-01

The HZ5-feline sarcoma virus (FeSV) is a new acute transforming feline retrovirus which was isolated from a multicentric fibrosarcoma of a domestic cat. The HZ5-FeSV transforms fibroblasts in vitro and is replication defective. A biologically active integrated HZ5-FeSV provirus was molecularly cloned from cellular DNA of HZ5-FeSV-infected FRE-3A rat cells. The HZ5-FeSV has oncogene homology with the fms sequences of the SM-FeSV. The genome organization of the 8.6-kilobase HZ5-FeSV provirus is 5' ..delta..gag-fms-..delta..pol-..delta..env 3'. The HZ5- and SM-FeSVs display indistinguishable in vitro transformation characteristics, and the structures of the gag-fms transforming genes in the two viruses are very similar. Inmore » the HZ5-FeSV and the SM-FeSV, identical c-fms and feline leukemia virus p10 sequences form the 5' gag-fms junction. With regard to v-fms the two viruses are homologous up to 11 amino acids before the C terminus of the SM-FeSV v-fms protein. In HZ5-FeSV a segment of 362 nucleotides then follows before the 3' recombination site with feline leukemia virus pol. The new 3' v-fms sequence encodes 27 amino acids before reaching a TGA termination signal. The relationship of this sequence with the recently characterized human c-fms sequence has been examined. The 3' HZ5-FeSV v-fms sequence is homologous with 3' c-fms sequences. A frameshift mutation (11-base-pair deletion) was found in the C-terminal fms coding sequence of the HZ5-FeSV. As a result, the HZ5-FeSV v-fms protein is predicted to be a C-terminally truncated version of c-fms. This frameshift mutation may determine the oncogenic properties of v-fms in the HZ5-FeSV.« less

Inverse statistical physics of protein sequences: a key issues review.

PubMed

Cocco, Simona; Feinauer, Christoph; Figliuzzi, Matteo; Monasson, Rémi; Weigt, Martin

2018-03-01

In the course of evolution, proteins undergo important changes in their amino acid sequences, while their three-dimensional folded structure and their biological function remain remarkably conserved. Thanks to modern sequencing techniques, sequence data accumulate at unprecedented pace. This provides large sets of so-called homologous, i.e. evolutionarily related protein sequences, to which methods of inverse statistical physics can be applied. Using sequence data as the basis for the inference of Boltzmann distributions from samples of microscopic configurations or observables, it is possible to extract information about evolutionary constraints and thus protein function and structure. Here we give an overview over some biologically important questions, and how statistical-mechanics inspired modeling approaches can help to answer them. Finally, we discuss some open questions, which we expect to be addressed over the next years.

Inverse statistical physics of protein sequences: a key issues review

NASA Astrophysics Data System (ADS)

Cocco, Simona; Feinauer, Christoph; Figliuzzi, Matteo; Monasson, Rémi; Weigt, Martin

2018-03-01

In the course of evolution, proteins undergo important changes in their amino acid sequences, while their three-dimensional folded structure and their biological function remain remarkably conserved. Thanks to modern sequencing techniques, sequence data accumulate at unprecedented pace. This provides large sets of so-called homologous, i.e. evolutionarily related protein sequences, to which methods of inverse statistical physics can be applied. Using sequence data as the basis for the inference of Boltzmann distributions from samples of microscopic configurations or observables, it is possible to extract information about evolutionary constraints and thus protein function and structure. Here we give an overview over some biologically important questions, and how statistical-mechanics inspired modeling approaches can help to answer them. Finally, we discuss some open questions, which we expect to be addressed over the next years.

Organic acid-tolerant microorganisms and uses thereof for producing organic acids

DOEpatents

Pfleger, Brian Frederick; Begemann, Matthew Brett

2014-05-06

Organic acid-tolerant microorganisms and methods of using same. The organic acid-tolerant microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid (3HP), acrylic acid, and propionic acid. Further modifications to the microorganisms such as increasing expression of malonyl-CoA reductase and/or acetyl-CoA carboxylase provide or increase the ability of the microorganisms to produce 3HP. Methods of generating an organic acid with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers include replacing acsA or homologs thereof in cells with genes of interest and selecting for the cells comprising the genes of interest with amounts of organic acids effective to inhibit growth of cells harboring acsA or the homologs.

Molecular cloning in Arabidopsis thaliana of a new protein phosphatase 2C (PP2C) with homology to ABI1 and ABI2.

PubMed

Rodriguez, P L; Leube, M P; Grill, E

1998-11-01

We report the cloning of both the cDNA and the corresponding genomic sequence of a new PP2C from Arabidopsis thaliana, named AtP2C-HA (for homology to ABI1/ABI2). The AtP2C-HA cDNA contains an open reading frame of 1536 bp and encodes a putative protein of 511 amino acids with a predicted molecular mass of 55.7 kDa. The AtP2C-HA protein is composed of two domains, a C-terminal PP2C catalytic domain and a N-terminal extension of ca. 180 amino acid residues. The deduced amino acid sequence is 55% and 54% identical to ABI1 and ABI2, respectively. Comparison of the genomic structure of the ABI1, ABI2 and AtP2C-HA genes suggests that they belong to a multigene family. The expression of the AtP2C-HA gene is up-regulated by abscisic acid (ABA) treatment.

The 86-kilodalton antigen from Schistosoma mansoni is a heat-shock protein homologous to yeast HSP-90.

PubMed

Johnson, K S; Wells, K; Bock, J V; Nene, V; Taylor, D W; Cordingley, J S

1989-08-01

We report the sequence of a cDNA clone encoding an 86-kDa polypeptide antigen (p86) from Schistosoma mansoni. Fusion proteins made in Escherichia coli are recognized by human infection sera. The reading frame of this antigen is highly homologous to those of the large heat-shock proteins of Saccharomyces cerevisiae (HSP90) and Drosophila melanogaster (HSP83). mRNA encoding p86 increases in response to heat shock of adult worms, as does HSP70. Comparisons of the sequences of HSP70 and HSP83 homologues show that these two families of heat-shock proteins are not significantly related except for the last four amino acid residues, which are Glu-Glu-Val-Asp in every case. This sequence is not found at the carboxy terminus of any other protein in the current databases.

Nucleotide sequencing and serological evidence that the recently recognized deer tick virus is a genotype of Powassan virus.

PubMed

Beasley, D W; Suderman, M T; Holbrook, M R; Barrett, A D

2001-11-05

Deer tick virus (DTV) is a recently recognized North American virus isolated from Ixodes dammini ticks. Nucleotide sequencing of fragments of structural and non-structural protein genes suggested that this virus was most closely related to the tick-borne flavivirus Powassan (POW), which causes potentially fatal encephalitis in humans. To determine whether DTV represents a new and distinct member of the Flavivirus genus of the family Flaviviridae, we sequenced the structural protein genes and 5' and 3' non-coding regions of this virus. In addition, we compared the reactivity of DTV and POW in hemagglutination inhibition tests with a panel of polyclonal and monoclonal antisera, and performed cross-neutralization experiments using anti-DTV antisera. Nucleotide sequencing revealed a high degree of homology between DTV and POW at both nucleotide (>80% homology) and amino acid (>90% homology) levels, and the two viruses were indistinguishable in serological assays and mouse neuroinvasiveness. On the basis of these results, we suggest that DTV should be classified as a genotype of POW virus.

AlloRep: A Repository of Sequence, Structural and Mutagenesis Data for the LacI/GalR Transcription Regulators.

PubMed

Sousa, Filipa L; Parente, Daniel J; Shis, David L; Hessman, Jacob A; Chazelle, Allen; Bennett, Matthew R; Teichmann, Sarah A; Swint-Kruse, Liskin

2016-02-22

Protein families evolve functional variation by accumulating point mutations at functionally important amino acid positions. Homologs in the LacI/GalR family of transcription regulators have evolved to bind diverse DNA sequences and allosteric regulatory molecules. In addition to playing key roles in bacterial metabolism, these proteins have been widely used as a model family for benchmarking structural and functional prediction algorithms. We have collected manually curated sequence alignments for >3000 sequences, in vivo phenotypic and biochemical data for >5750 LacI/GalR mutational variants, and noncovalent residue contact networks for 65 LacI/GalR homolog structures. Using this rich data resource, we compared the noncovalent residue contact networks of the LacI/GalR subfamilies to design and experimentally validate an allosteric mutant of a synthetic LacI/GalR repressor for use in biotechnology. The AlloRep database (freely available at www.AlloRep.org) is a key resource for future evolutionary studies of LacI/GalR homologs and for benchmarking computational predictions of functional change. Copyright © 2015 Elsevier Ltd. All rights reserved.

HasF, a TolC-homolog of Serratia marcescens, is involved in energy-dependent efflux.

PubMed

Kumar, Ayush; Worobec, Elizabeth A

2005-06-01

A tolC-like gene (hasF) was identified upon scanning the incomplete database of the S. marcescens genome. This gene was amplified using PCR and cloned in the pUC18 vector to yield pUCHF. Sequencing of the S. marcescens tolC-like hasF gene and subsequent amino acid sequence prediction revealed approximately 80% amino acid homology with the Escherichia coli TolC. A tolC-deficient strain of E. coli (BL923) containing pUCHF/hasF was analyzed for susceptibility to fluoroquinolones (ciprofloxacin, norfloxacin, and ofloxacin), chloramphenicol, sodium dodecyl sulfate (SDS), and ethidium bromide. Antibiotic susceptibility assays of the E. coli tolC-deficient mutant BL923 demonstrated a 64-fold increase in resistance to SDS and ethidium bromide upon introduction of the S. marcescens tolC-like hasF gene. No change was observed for susceptibility to fluoroquinolones and chloramphenicol. Ethidium bromide accumulation assays performed using E. coli BL923:pUCHF established the role of the S. marcescens hasF gene product in proton gradient-dependent efflux.

A new acute transforming feline retrovirus with fms homology specifies a C-terminally truncated version of the c-fms protein that is different from SM-feline sarcoma virus v-fms protein.

PubMed Central

Besmer, P; Lader, E; George, P C; Bergold, P J; Qiu, F H; Zuckerman, E E; Hardy, W D

1986-01-01

The HZ5-feline sarcoma virus (FeSV) is a new acute transforming feline retrovirus which was isolated from a multicentric fibrosarcoma of a domestic cat. The HZ5-FeSV transforms fibroblasts in vitro and is replication defective. A biologically active integrated HZ5-FeSV provirus was molecularly cloned from cellular DNA of HZ5-FeSV-infected FRE-3A rat cells. The HZ5-FeSV has oncogene homology with the fms sequences of the SM-FeSV. The genome organization of the 8.6-kilobase HZ5-FeSV provirus is 5' delta gag-fms-delta pol-delta env 3'. The HZ5-and SM-FeSVs display indistinguishable in vitro transformation characteristics, and the structures of the gag-fms transforming genes in the two viruses are very similar. In the HZ5-FeSV and the SM-FeSV, identical c-fms and feline leukemia virus p10 sequences form the 5' gag-fms junction. With regard to v-fms the two viruses are homologous up to 11 amino acids before the C terminus of the SM-FeSV v-fms protein. In HZ5-FeSV a segment of 362 nucleotides then follows before the 3' recombination site with feline leukemia virus pol. The new 3' v-fms sequence encodes 27 amino acids before reaching a TGA termination signal. The relationship of this sequence with the recently characterized human c-fms sequence has been examined. The 3' HZ5-FeSV v-fms sequence is homologous with 3' c-fms sequences. A frameshift mutation (11-base-pair deletion) was found in the C-terminal fms coding sequence of the HZ5-FeSV. As a result, the HZ5-FeSV v-fms protein is predicted to be a C-terminally truncated version of c-fms. This frameshift mutation may determine the oncogenic properties of v-fms in the HZ5-FeSV. Images PMID:3018286

RAD25 (SSL2), the yeast homolog of the human xeroderma pigmentosum group B DNA repair gene, is essential for viability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, E.; Prakash, L.; Guzder, S.N.

1992-12-01

Xeroderma pigmentosum (XP) patients are extremely sensitive to ultraviolet (UV) light and suffer from a high incidence of skin cancers, due to a defect in nucleotide excision repair. The disease is genetically heterogeneous, and seven complementation groups, A-G, have been identified. Homologs of human excision repair genes ERCC1, XPDC/ERCC2, and XPAC have been identified in the yeast Saccharomyces cerevisiae. Since no homolog of human XPBC/ERCC3 existed among the known yeast genes, we cloned the yeast homolog by using XPBC cDNA as a hybridization probe. The yeast homolog, RAD25 (SSL2), encodes a protein of 843 amino acids (M[sub r] 95,356). Themore » RAD25 (SSL2)- and XPCX-encoded proteins share 55% identical and 72% conserved amino acid residues, and the two proteins resemble one another in containing the conserved DNA helicase sequence motifs. A nonsense mutation at codon 799 that deletes the 45 C-terminal amino acid residues in RAD25 (SSL2) confers UV sensitivity. This mutation shows epistasis with genes in the excision repair group, whereas a synergistic increase in UN sensitivity occurs when it is combined with mutations in genes in other DNA repair pathways, indicating that RAD25 (SSL2) functions in excision repair but not in other repair pathways. We also show that RAD25 (SSL2) is an essential gene. A mutation of the Lys[sup 392] residue to arginine in the conserved Walker type A nucleotide-binding motif is lethal, suggesting an essential role of the putative RAD 25 (SSL2) ATPase/DNA helicase activity in viability. 40 refs., 3 figs., 1 tab.« less

WEB-server for search of a periodicity in amino acid and nucleotide sequences

NASA Astrophysics Data System (ADS)

E Frenkel, F.; Skryabin, K. G.; Korotkov, E. V.

2017-12-01

A new web server (http://victoria.biengi.ac.ru/splinter/login.php) was designed and developed to search for periodicity in nucleotide and amino acid sequences. The web server operation is based upon a new mathematical method of searching for multiple alignments, which is founded on the position weight matrices optimization, as well as on implementation of the two-dimensional dynamic programming. This approach allows the construction of multiple alignments of the indistinctly similar amino acid and nucleotide sequences that accumulated more than 1.5 substitutions per a single amino acid or a nucleotide without performing the sequences paired comparisons. The article examines the principles of the web server operation and two examples of studying amino acid and nucleotide sequences, as well as information that could be obtained using the web server.

Detection and isolation of nucleic acid sequences using a bifunctional hybridization probe

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

2000-01-01

A method for detecting and isolating a target sequence in a sample of nucleic acids is provided using a bifunctional hybridization probe capable of hybridizing to the target sequence that includes a detectable marker and a first complexing agent capable of forming a binding pair with a second complexing agent. A kit is also provided for detecting a target sequence in a sample of nucleic acids using a bifunctional hybridization probe according to this method.

Nucleotide sequence of a complementary DNA encoding pea cytosolic copper/zinc superoxide dismutase. [Pisum sativum L

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, D.A.; Zilinskas, B.A.

1991-08-01

The authors now report the nucleotide sequence of the cytosolic Cu/Zn SOD cloned from a {lambda}gt11 cDNA library constructed from mRNA extracted from leaves of 7- to 10-d pea seedlings (Pisum sativum L.). The clone was isolated using a 22-base synthetic oligonucleotide complementary to the amino acid sequence CGIIGLQG. This sequence, found at the protein's carboxy terminus, is highly conserved among plant cytosolic Cu/Zn SODs but not chloroplastic Cu/Zn SODs. The 738-base pair sequence contains an open reading frame specifying 152 codons and a predicted M{sub r} of 18,024 D. The deduced amino acid sequence is highly homologous (79-82% identity)more » with the sequences of other known plant cytosolic Cu/Zn SODs but less highly conserved (63-65%) when compared with several chloroplastic Cu/Zn SODs including pea (10).« less

Whole genome analysis of CRISPR Cas9 sgRNA off-target homologies via an efficient computational algorithm.

PubMed

Zhou, Hong; Zhou, Michael; Li, Daisy; Manthey, Joseph; Lioutikova, Ekaterina; Wang, Hong; Zeng, Xiao

2017-11-17

The beauty and power of the genome editing mechanism, CRISPR Cas9 endonuclease system, lies in the fact that it is RNA-programmable such that Cas9 can be guided to any genomic loci complementary to a 20-nt RNA, single guide RNA (sgRNA), to cleave double stranded DNA, allowing the introduction of wanted mutations. Unfortunately, it has been reported repeatedly that the sgRNA can also guide Cas9 to off-target sites where the DNA sequence is homologous to sgRNA. Using human genome and Streptococcus pyogenes Cas9 (SpCas9) as an example, this article mathematically analyzed the probabilities of off-target homologies of sgRNAs and discovered that for large genome size such as human genome, potential off-target homologies are inevitable for sgRNA selection. A highly efficient computationl algorithm was developed for whole genome sgRNA design and off-target homology searches. By means of a dynamically constructed sequence-indexed database and a simplified sequence alignment method, this algorithm achieves very high efficiency while guaranteeing the identification of all existing potential off-target homologies. Via this algorithm, 1,876,775 sgRNAs were designed for the 19,153 human mRNA genes and only two sgRNAs were found to be free of off-target homology. By means of the novel and efficient sgRNA homology search algorithm introduced in this article, genome wide sgRNA design and off-target analysis were conducted and the results confirmed the mathematical analysis that for a sgRNA sequence, it is almost impossible to escape potential off-target homologies. Future innovations on the CRISPR Cas9 gene editing technology need to focus on how to eliminate the Cas9 off-target activity.

Exploring representations of protein structure for automated remote homology detection and mapping of protein structure space

PubMed Central

2014-01-01

Background Due to rapid sequencing of genomes, there are now millions of deposited protein sequences with no known function. Fast sequence-based comparisons allow detecting close homologs for a protein of interest to transfer functional information from the homologs to the given protein. Sequence-based comparison cannot detect remote homologs, in which evolution has adjusted the sequence while largely preserving structure. Structure-based comparisons can detect remote homologs but most methods for doing so are too expensive to apply at a large scale over structural databases of proteins. Recently, fragment-based structural representations have been proposed that allow fast detection of remote homologs with reasonable accuracy. These representations have also been used to obtain linearly-reducible maps of protein structure space. It has been shown, as additionally supported from analysis in this paper that such maps preserve functional co-localization of the protein structure space. Methods Inspired by a recent application of the Latent Dirichlet Allocation (LDA) model for conducting structural comparisons of proteins, we propose higher-order LDA-obtained topic-based representations of protein structures to provide an alternative route for remote homology detection and organization of the protein structure space in few dimensions. Various techniques based on natural language processing are proposed and employed to aid the analysis of topics in the protein structure domain. Results We show that a topic-based representation is just as effective as a fragment-based one at automated detection of remote homologs and organization of protein structure space. We conduct a detailed analysis of the information content in the topic-based representation, showing that topics have semantic meaning. The fragment-based and topic-based representations are also shown to allow prediction of superfamily membership. Conclusions This work opens exciting venues in designing novel

Substitution of a single amino acid residue in the aromatic/arginine selectivity filter alters the transport profiles of tonoplast aquaporin homologs.

PubMed

Azad, Abul Kalam; Yoshikawa, Naoki; Ishikawa, Takahiro; Sawa, Yoshihiro; Shibata, Hitoshi

2012-01-01

Aquaporins are integral membrane proteins that facilitate the transport of water and some small solutes across cellular membranes. X-ray crystallography of aquaporins indicates that four amino acids constitute an aromatic/arginine (ar/R) pore constriction known as the selectivity filter. On the basis of these four amino acids, tonoplast aquaporins called tonoplast intrinsic proteins (TIPs) are divided into three groups in Arabidopsis. Herein, we describe the characterization of two group I TIP1s (TgTIP1;1 and TgTIP1;2) from tulip (Tulipa gesneriana). TgTIP1;1 and TgTIP1;2 have a novel isoleucine in loop E (LE2 position) of the ar/R filter; the residue at LE2 is a valine in all group I TIPs from model plants. The homologs showed mercury-sensitive water channel activity in a fast kinetics swelling assay upon heterologous expression in Pichia pastoris. Heterologous expression of both homologs promoted the growth of P. pastoris on ammonium or urea as sole sources of nitrogen and decreased growth and survival in the presence of H(2)O(2). TgTIP1;1- and TgTIP1;2-mediated H(2)O(2) conductance was demonstrated further by a fluorescence assay. Substitutions in the ar/R selectivity filter of TgTIP1;1 showed that mutants that mimicked the ar/R constriction of group I TIPs could conduct the same substrates that were transported by wild-type TgTIP1;1. In contrast, mutants that mimicked group II TIPs showed no evidence of urea or H(2)O(2) conductance. These results suggest that the amino acid residue at LE2 position is critical for the transport selectivity of the TIP homologs and group I TIPs might have a broader spectrum of substrate selectivity than group II TIPs. Copyright © 2011 Elsevier B.V. All rights reserved.

Nucleotide Sequence and Genetic Structure of a Novel Carbaryl Hydrolase Gene (cehA) from Rhizobium sp. Strain AC100

PubMed Central

Hashimoto, Masayuki; Fukui, Mitsuru; Hayano, Kouichi; Hayatsu, Masahito

2002-01-01

Rhizobium sp. strain AC100, which is capable of degrading carbaryl (1-naphthyl-N-methylcarbamate), was isolated from soil treated with carbaryl. This bacterium hydrolyzed carbaryl to 1-naphthol and methylamine. Carbaryl hydrolase from the strain was purified to homogeneity, and its N-terminal sequence, molecular mass (82 kDa), and enzymatic properties were determined. The purified enzyme hydrolyzed 1-naphthyl acetate and 4-nitrophenyl acetate indicating that the enzyme is an esterase. We then cloned the carbaryl hydrolase gene (cehA) from the plasmid DNA of the strain and determined the nucleotide sequence of the 10-kb region containing cehA. No homologous sequences were found by a database homology search using the nucleotide and deduced amino acid sequences of the cehA gene. Six open reading frames including the cehA gene were found in the 10-kb region, and sequencing analysis shows that the cehA gene is flanked by two copies of insertion sequence-like sequence, suggesting that it makes part of a composite transposon. PMID:11872471

MollDE: a homology modeling framework you can click with.

PubMed

Canutescu, Adrian A; Dunbrack, Roland L

2005-06-15

Molecular Integrated Development Environment (MolIDE) is an integrated application designed to provide homology modeling tools and protocols under a uniform, user-friendly graphical interface. Its main purpose is to combine the most frequent modeling steps in a semi-automatic, interactive way, guiding the user from the target protein sequence to the final three-dimensional protein structure. The typical basic homology modeling process is composed of building sequence profiles of the target sequence family, secondary structure prediction, sequence alignment with PDB structures, assisted alignment editing, side-chain prediction and loop building. All of these steps are available through a graphical user interface. MolIDE's user-friendly and streamlined interactive modeling protocol allows the user to focus on the important modeling questions, hiding from the user the raw data generation and conversion steps. MolIDE was designed from the ground up as an open-source, cross-platform, extensible framework. This allows developers to integrate additional third-party programs to MolIDE. http://dunbrack.fccc.edu/molide/molide.php rl_dunbrack@fccc.edu.

Sequence space and the ongoing expansion of the protein universe.

PubMed

Povolotskaya, Inna S; Kondrashov, Fyodor A

2010-06-17

The need to maintain the structural and functional integrity of an evolving protein severely restricts the repertoire of acceptable amino-acid substitutions. However, it is not known whether these restrictions impose a global limit on how far homologous protein sequences can diverge from each other. Here we explore the limits of protein evolution using sequence divergence data. We formulate a computational approach to study the rate of divergence of distant protein sequences and measure this rate for ancient proteins, those that were present in the last universal common ancestor. We show that ancient proteins are still diverging from each other, indicating an ongoing expansion of the protein sequence universe. The slow rate of this divergence is imposed by the sparseness of functional protein sequences in sequence space and the ruggedness of the protein fitness landscape: approximately 98 per cent of sites cannot accept an amino-acid substitution at any given moment but a vast majority of all sites may eventually be permitted to evolve when other, compensatory, changes occur. Thus, approximately 3.5 x 10(9) yr has not been enough to reach the limit of divergent evolution of proteins, and for most proteins the limit of sequence similarity imposed by common function may not exceed that of random sequences.

Investigating homology between proteins using energetic profiles.

PubMed

Wrabl, James O; Hilser, Vincent J

2010-03-26

Accumulated experimental observations demonstrate that protein stability is often preserved upon conservative point mutation. In contrast, less is known about the effects of large sequence or structure changes on the stability of a particular fold. Almost completely unknown is the degree to which stability of different regions of a protein is generally preserved throughout evolution. In this work, these questions are addressed through thermodynamic analysis of a large representative sample of protein fold space based on remote, yet accepted, homology. More than 3,000 proteins were computationally analyzed using the structural-thermodynamic algorithm COREX/BEST. Estimated position-specific stability (i.e., local Gibbs free energy of folding) and its component enthalpy and entropy were quantitatively compared between all proteins in the sample according to all-vs.-all pairwise structural alignment. It was discovered that the local stabilities of homologous pairs were significantly more correlated than those of non-homologous pairs, indicating that local stability was indeed generally conserved throughout evolution. However, the position-specific enthalpy and entropy underlying stability were less correlated, suggesting that the overall regional stability of a protein was more important than the thermodynamic mechanism utilized to achieve that stability. Finally, two different types of statistically exceptional evolutionary structure-thermodynamic relationships were noted. First, many homologous proteins contained regions of similar thermodynamics despite localized structure change, suggesting a thermodynamic mechanism enabling evolutionary fold change. Second, some homologous proteins with extremely similar structures nonetheless exhibited different local stabilities, a phenomenon previously observed experimentally in this laboratory. These two observations, in conjunction with the principal conclusion that homologous proteins generally conserved local stability, may

Identification and characterization of a triacylglycerol lipase in Arabidopsis homologous to mammalian acid lipases.

PubMed

El-Kouhen, Karim; Blangy, Stéphanie; Ortiz, Emilia; Gardies, Anne-Marie; Ferté, Natalie; Arondel, Vincent

2005-11-07

Triacylglycerol (TAG) lipases have been thoroughly characterized in mammals and microorganisms. By contrast, very little is known on plant TAG lipases. An Arabidopsis cDNA called AtLip1 (At2g15230), which exhibits strong homology to lysosomal acid lipase, was found to drive the synthesis of an active TAG lipase when expressed in the baculovirus system. The lipase had a maximal activity at pH 6 and the specific activity was estimated to be about 45 micromol min(-1) mg(-1) protein using triolein as a substrate. Knock-out mutant analysis showed no phenotype during germination indicating that this enzyme is fully dispensable for TAG storage breakdown during germination. Northern blot analyses indicated that the transcript is present in all tissues tested.

Soil amino acid composition across a boreal forest successional sequence

Treesearch

Nancy R. Werdin-Pfisterer; Knut Kielland; Richard D. Boone

2009-01-01

Soil amino acids are important sources of organic nitrogen for plant nutrition, yet few studies have examined which amino acids are most prevalent in the soil. In this study, we examined the composition, concentration, and seasonal patterns of soil amino acids across a primary successional sequence encompassing a natural gradient of plant productivity and soil...

Preferential amino acid sequences in alumina-catalyzed peptide bond formation.

PubMed

Bujdák, J; Rode, B M

2002-05-21

The catalytic effect of activated alumina on amino acid condensation was investigated. The readiness of amino acids to form peptide sequences was estimated on the basis of the yield of dipeptides and was found to decrease in the order glycine (Gly), alanine (Ala), leucine (Leu), valine (Val), proline (Pro). For example, approximately 15% Gly was converted to the dipeptide (Gly(2)), 5% to cyclic anhydride (cyc(Gly(2))) and small amounts of tri- (Gly(3)) and tetrapeptide (Gly(4)) were formed after 28 days. On the other hand, only trace amounts of Pro(2) were formed from proline under the same conditions. Preferential formation of certain sequences was observed in the mixed reaction systems containing two amino acids. For example, almost ten times more Gly-Val than Val-Gly was formed in the Gly+Val reaction system. The preferred sequences can be explained on the basis of an inductive effect that side groups have on the nucleophilicity and electrophilicity, respectively, of the amino and carboxyl groups. A comparison with published data of amino acid reactions in other reaction systems revealed that the main trends of preferential sequence formation were the same as those described for the salt-induced peptide formation (SIPF) reaction. The results of this work and other previously published papers show that alumina and related mineral surfaces might have played a crucial role in the prebiotic formation of the first peptides on the primitive earth.

Complete Unique Genome Sequence, Expression Profile, and Salivary Gland Tissue Tropism of the Herpesvirus 7 Homolog in Pigtailed Macaques.

PubMed

Staheli, Jeannette P; Dyen, Michael R; Deutsch, Gail H; Basom, Ryan S; Fitzgibbon, Matthew P; Lewis, Patrick; Barcy, Serge

2016-08-01

Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses and are highly prevalent in the human population. Roseolovirus reactivation in an immunocompromised host can cause severe pathologies. While the pathogenic potential of HHV-7 is unclear, it can reactivate HHV-6 from latency and thus contributes to severe pathological conditions associated with HHV-6. Because of the ubiquitous nature of roseoloviruses, their roles in such interactions and the resulting pathological consequences have been difficult to study. Furthermore, the lack of a relevant animal model for HHV-7 infection has hindered a better understanding of its contribution to roseolovirus-associated diseases. Using next-generation sequencing analysis, we characterized the unique genome of an uncultured novel pigtailed macaque roseolovirus. Detailed genomic analysis revealed the presence of gene homologs to all 84 known HHV-7 open reading frames. Phylogenetic analysis confirmed that the virus is a macaque homolog of HHV-7, which we have provisionally named Macaca nemestrina herpesvirus 7 (MneHV7). Using high-throughput RNA sequencing, we observed that the salivary gland tissue samples from nine different macaques had distinct MneHV7 gene expression patterns and that the overall number of viral transcripts correlated with viral loads in parotid gland tissue and saliva. Immunohistochemistry staining confirmed that, like HHV-7, MneHV7 exhibits a natural tropism for salivary gland ductal cells. We also observed staining for MneHV7 in peripheral nerve ganglia present in salivary gland tissues, suggesting that HHV-7 may also have a tropism for the peripheral nervous system. Our data demonstrate that MneHV7-infected macaques represent a relevant animal model that may help clarify the causality between roseolovirus reactivation and diseases. Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses. We have recently discovered that pigtailed macaques are naturally

Complete Unique Genome Sequence, Expression Profile, and Salivary Gland Tissue Tropism of the Herpesvirus 7 Homolog in Pigtailed Macaques

PubMed Central

Staheli, Jeannette P.; Dyen, Michael R.; Deutsch, Gail H.; Basom, Ryan S.; Fitzgibbon, Matthew P.; Lewis, Patrick

2016-01-01

ABSTRACT Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses and are highly prevalent in the human population. Roseolovirus reactivation in an immunocompromised host can cause severe pathologies. While the pathogenic potential of HHV-7 is unclear, it can reactivate HHV-6 from latency and thus contributes to severe pathological conditions associated with HHV-6. Because of the ubiquitous nature of roseoloviruses, their roles in such interactions and the resulting pathological consequences have been difficult to study. Furthermore, the lack of a relevant animal model for HHV-7 infection has hindered a better understanding of its contribution to roseolovirus-associated diseases. Using next-generation sequencing analysis, we characterized the unique genome of an uncultured novel pigtailed macaque roseolovirus. Detailed genomic analysis revealed the presence of gene homologs to all 84 known HHV-7 open reading frames. Phylogenetic analysis confirmed that the virus is a macaque homolog of HHV-7, which we have provisionally named Macaca nemestrina herpesvirus 7 (MneHV7). Using high-throughput RNA sequencing, we observed that the salivary gland tissue samples from nine different macaques had distinct MneHV7 gene expression patterns and that the overall number of viral transcripts correlated with viral loads in parotid gland tissue and saliva. Immunohistochemistry staining confirmed that, like HHV-7, MneHV7 exhibits a natural tropism for salivary gland ductal cells. We also observed staining for MneHV7 in peripheral nerve ganglia present in salivary gland tissues, suggesting that HHV-7 may also have a tropism for the peripheral nervous system. Our data demonstrate that MneHV7-infected macaques represent a relevant animal model that may help clarify the causality between roseolovirus reactivation and diseases. IMPORTANCE Human herpesvirus 6A (HHV-6A), HHV-6B, and HHV-7 are classified as roseoloviruses. We have recently discovered that pigtailed

37 CFR 1.821 - Nucleotide and/or amino acid sequence disclosures in patent applications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Nucleotide and/or amino acid... Biotechnology Invention Disclosures Application Disclosures Containing Nucleotide And/or Amino Acid Sequences § 1.821 Nucleotide and/or amino acid sequence disclosures in patent applications. (a) Nucleotide and...

37 CFR 1.821 - Nucleotide and/or amino acid sequence disclosures in patent applications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Nucleotide and/or amino acid... Biotechnology Invention Disclosures Application Disclosures Containing Nucleotide And/or Amino Acid Sequences § 1.821 Nucleotide and/or amino acid sequence disclosures in patent applications. (a) Nucleotide and...

Identification of MicroRNAs in Helicoverpa armigera and Spodoptera litura Based on Deep Sequencing and Homology Analysis

PubMed Central

Ge, Xie; Zhang, Yong; Jiang, Jianhao; Zhong, Yi; Yang, Xiaonan; Li, Zhiqian; Huang, Yongping; Tan, Anjiang

2013-01-01

The current identification of microRNAs (miRNAs) in insects is largely dependent on genome sequences. However, the lack of available genome sequences inhibits the identification of miRNAs in various insect species. In this study, we used a miRNA database of the silkworm Bombyx mori as a reference to identify miRNAs in Helicoverpa armigera and Spodoptera litura using deep sequencing and homology analysis. Because all three species belong to the Lepidoptera, the experiment produced reliable results. Our study identified 97 and 91 conserved miRNAs in H. armigera and S. litura, respectively. Using the genome of B. mori and BAC sequences of H. armigera as references, 1 novel miRNA and 8 novel miRNA candidates were identified in H. armigera, and 4 novel miRNA candidates were identified in S. litura. An evolutionary analysis revealed that most of the identified miRNAs were insect-specific, and more than 20 miRNAs were Lepidoptera-specific. The investigation of the expression patterns of miR-2a, miR-34, miR-2796-3p and miR-11 revealed their potential roles in insect development. miRNA target prediction revealed that conserved miRNA target sites exist in various genes in the 3 species. Conserved miRNA target sites for the Hsp90 gene among the 3 species were validated in the mammalian 293T cell line using a dual-luciferase reporter assay. Our study provides a new approach with which to identify miRNAs in insects lacking genome information and contributes to the functional analysis of insect miRNAs. PMID:23289012

Rapid Hypothesis Testing with Candida albicans through Gene Disruption with Short Homology Regions

PubMed Central

Wilson, R. Bryce; Davis, Dana; Mitchell, Aaron P.

1999-01-01

Disruption of newly identified genes in the pathogen Candida albicans is a vital step in determination of gene function. Several gene disruption methods described previously employ long regions of homology flanking a selectable marker. Here, we describe disruption of C. albicans genes with PCR products that have 50 to 60 bp of homology to a genomic sequence on each end of a selectable marker. We used the method to disrupt two known genes, ARG5 and ADE2, and two sequences newly identified through the Candida genome project, HRM101 and ENX3. HRM101 and ENX3 are homologous to genes in the conserved RIM101 (previously called RIM1) and PacC pathways of Saccharomyces cerevisiae and Aspergillus nidulans. We show that three independent hrm101/hrm101 mutants and two independent enx3/enx3 mutants are defective in filamentation on Spider medium. These observations argue that HRM101 and ENX3 sequences are indeed portions of genes and that the respective gene products have related functions. PMID:10074081

Universal sequence map (USM) of arbitrary discrete sequences

PubMed Central

2002-01-01

Background For over a decade the idea of representing biological sequences in a continuous coordinate space has maintained its appeal but not been fully realized. The basic idea is that any sequence of symbols may define trajectories in the continuous space conserving all its statistical properties. Ideally, such a representation would allow scale independent sequence analysis – without the context of fixed memory length. A simple example would consist on being able to infer the homology between two sequences solely by comparing the coordinates of any two homologous units. Results We have successfully identified such an iterative function for bijective mappingψ of discrete sequences into objects of continuous state space that enable scale-independent sequence analysis. The technique, named Universal Sequence Mapping (USM), is applicable to sequences with an arbitrary length and arbitrary number of unique units and generates a representation where map distance estimates sequence similarity. The novel USM procedure is based on earlier work by these and other authors on the properties of Chaos Game Representation (CGR). The latter enables the representation of 4 unit type sequences (like DNA) as an order free Markov Chain transition table. The properties of USM are illustrated with test data and can be verified for other data by using the accompanying web-based tool:http://bioinformatics.musc.edu/~jonas/usm/. Conclusions USM is shown to enable a statistical mechanics approach to sequence analysis. The scale independent representation frees sequence analysis from the need to assume a memory length in the investigation of syntactic rules. PMID:11895567

Identification of a human src homology 2-containing protein-tyrosine-phosphatase: a putative homolog of Drosophila corkscrew.

PubMed Central

Freeman, R M; Plutzky, J; Neel, B G

1992-01-01

src homology 2 (SH2) domains direct binding to specific phosphotyrosyl proteins. Recently, SH2-containing protein-tyrosine-phosphatases (PTPs) were identified. Using degenerate oligonucleotides and the PCR, we have cloned a cDNA for an additional PTP, SH-PTP2, which contains two SH2 domains and is expressed ubiquitously. When expressed in Escherichia coli, SH-PTP2 displays tyrosine-specific phosphatase activity. Strong sequence similarity between SH-PTP2 and the Drosophila gene corkscrew (csw) and their similar patterns of expression suggest that SH-PTP2 is the human corkscrew homolog. Sequence comparisons between SH-PTP2, SH-PTP1, corkscrew, and other SH2-containing proteins suggest the existence of a subfamily of SH2 domains found specifically in PTPs, whereas comparison of the PTP domains of the SH2-containing PTPs with other tyrosine phosphatases suggests the existence of a subfamily of PTPs containing SH2 domains. Since corkscrew, a member of the terminal class signal transduction pathway, acts in concert with D-raf to positively transduce the signal generated by the receptor tyrosine kinase torso, these findings suggest several mechanisms by which SH-PTP2 may participate in mammalian signal transduction. Images PMID:1280823

[Cloning and sequence analysis of 55 K protein of egg drop syndrome virus].

PubMed

Zhu, L; Jin, Q; Zeng, L

1999-06-30

For understanding the characteristics of genomic structure of egg drop syndrome virus(EDSV). Nucleic acid was extracted using routine method from weak virulent strain AA-2 of EDSV isolated from Chinese sick hens. Construction of the whole genomic library was by hydrolysis with Hind III, strand encoding 55 K gene locating in Hind III--A segment was sequenced and analyzed. The open reading frame has a length of 1,014 nt and codes a polypeptide of 337 amino acids with molecular weight of 38,200. Analysis of the amino acid sequence revealed a homology from 25.5%-32.4% to the 55 K protein of human adenovirus types 2, 12, 40, canine adenovirus and fowl adenoviruses of group 1, whereas to ovine adenovirus is 46.4%. The genomic structure of EDSV has some relationship with adenoviruses.

Evolutionary distance from human homologs reflects allergenicity of animal food proteins.

PubMed

Jenkins, John A; Breiteneder, Heimo; Mills, E N Clare

2007-12-01

In silico analysis of allergens can identify putative relationships among protein sequence, structure, and allergenic properties. Such systematic analysis reveals that most plant food allergens belong to a restricted number of protein superfamilies, with pollen allergens behaving similarly. We have investigated the structural relationships of animal food allergens and their evolutionary relatedness to human homologs to define how closely a protein must resemble a human counterpart to lose its allergenic potential. Profile-based sequence homology methods were used to classify animal food allergens into Pfam families, and in silico analyses of their evolutionary and structural relationships were performed. Animal food allergens could be classified into 3 main families--tropomyosins, EF-hand proteins, and caseins--along with 14 minor families each composed of 1 to 3 allergens. The evolutionary relationships of each of these allergen superfamilies showed that in general, proteins with a sequence identity to a human homolog above approximately 62% were rarely allergenic. Single substitutions in otherwise highly conserved regions containing IgE epitopes in EF-hand parvalbumins may modulate allergenicity. These data support the premise that certain protein structures are more allergenic than others. Contrasting with plant food allergens, animal allergens, such as the highly conserved tropomyosins, challenge the capability of the human immune system to discriminate between foreign and self-proteins. Such immune responses run close to becoming autoimmune responses. Exploiting the closeness between animal allergens and their human homologs in the development of recombinant allergens for immunotherapy will need to consider the potential for developing unanticipated autoimmune responses.

The complete amino acid sequence of human skeletal-muscle fructose-bisphosphate aldolase.

PubMed Central

Freemont, P S; Dunbar, B; Fothergill-Gilmore, L A

1988-01-01

The complete amino acid sequence of human skeletal-muscle fructose-bisphosphate aldolase, comprising 363 residues, was determined. The sequence was deduced by automated sequencing of CNBr-cleavage, o-iodosobenzoic acid-cleavage, trypsin-digest and staphylococcal-proteinase-digest fragments. Comparison of the sequence with other class I aldolase sequences shows that the mammalian muscle isoenzyme is one of the most highly conserved enzymes known, with only about 2% of the residues changing per 100 million years. Non-mammalian aldolases appear to be evolving at the same rate as other glycolytic enzymes, with about 4% of the residues changing per 100 million years. Secondary-structure predictions are analysed in an accompanying paper [Sawyer, Fothergill-Gilmore & Freemont (1988) Biochem. J. 249, 789-793]. PMID:3355497

Homology difference analysis of invasive mealybug species Phenacoccus solenopsis Tinsley in Southern China with COI gene sequence variability.

PubMed

Wu, F Z; Ma, J; Hu, X N; Zeng, L

2015-02-01

The mealybug species Phenacoccus solenopsis (P. solenopsis) has caused much agricultural damage since its recent invasion in China. However, the source of this invasion remains unclear. This study uses molecular methods to clarify the relationships among different population of P. solenopsis from China, USA, Pakistan, India, and Vietnam to determine the geographic origin of the introduction of this species into China. P. solenopsis samples were collected from 25 different locations in three provinces of Southern China. Samples from the USA, Pakistan, and Vietnam were also obtained. Parts of the mitochondrial genes for cytochrome oxidase I (COI) were sequenced for each sample. Homologous DNA sequences of the samples from the USA and India were downloaded from Gen Bank. Two haplotypes were found in China. The first was from most samples from the Guangdong, Guangxi, and Hainan populations in the China and Pakistan groups, and the second from a few samples from the Guangdong, Guangxi, Hainan populations in the China, Pakistan, India, and Vietnam groups. As shown in the maximum likelihood of trees constructed using the COI sequences, these samples belonged to two clades. Phylogenetic analysis suggested that most P. solenopsis mealybugs in Southern China are probably closely related to populations in Pakistan. The variation, relationship, expansion, and probable geographic origin of P. solenopsis mealybugs in Southern China are also discussed.

Molecular cloning and nucleotide sequence of the alpha and beta subunits of allophycocyanin from the cyanelle genome of Cyanophora paradoxa.

PubMed Central

Bryant, D A; de Lorimier, R; Lambert, D H; Dubbs, J M; Stirewalt, V L; Stevens, S E; Porter, R D; Tam, J; Jay, E

1985-01-01

The genes for the alpha- and beta-subunit apoproteins of allophycocyanin (AP) were isolated from the cyanelle genome of Cyanophora paradoxa and subjected to nucleotide sequence analysis. The AP beta-subunit apoprotein gene was localized to a 7.8-kilobase-pair Pst I restriction fragment from cyanelle DNA by hybridization with a tetradecameric oligonucleotide probe. Sequence analysis using that oligonucleotide and its complement as primers for the dideoxy chain-termination sequencing method confirmed the presence of both AP alpha- and beta-subunit genes on this restriction fragment. Additional oligonucleotide primers were synthesized as sequencing progressed and were used to determine rapidly the nucleotide sequence of a 1336-base-pair region of this cloned fragment. This strategy allowed the sequencing to be completed without a detailed restriction map and without extensive and time-consuming subcloning. The sequenced region contains two open reading frames whose deduced amino acid sequences are 81-85% homologous to cyanobacterial and red algal AP subunits whose amino acid sequences have been determined. The two open reading frames are in the same orientation and are separated by 39 base pairs. AP alpha is 5' to AP beta and both coding sequences are preceded by a polypurine, Shine-Dalgarno-type sequence. Sequences upstream from AP alpha closely resemble the Escherichia coli consensus promoter sequences and also show considerable homology to promoter sequences for several chloroplast-encoded psbA genes. A 56-base-pair palindromic sequence downstream from the AP beta gene could play a role in the termination of transcription or translation. The allophycocyanin apoprotein subunit genes are located on the large single-copy region of the cyanelle genome. PMID:2987916

Chromosome specific repetitive DNA sequences

DOEpatents

Moyzis, Robert K.; Meyne, Julianne

1991-01-01

A method is provided for determining specific nucleotide sequences useful in forming a probe which can identify specific chromosomes, preferably through in situ hybridization within the cell itself. In one embodiment, chromosome preferential nucleotide sequences are first determined from a library of recombinant DNA clones having families of repetitive sequences. Library clones are identified with a low homology with a sequence of repetitive DNA families to which the first clones respectively belong and variant sequences are then identified by selecting clones having a pattern of hybridization with genomic DNA dissimilar to the hybridization pattern shown by the respective families. In another embodiment, variant sequences are selected from a sequence of a known repetitive DNA family. The selected variant sequence is classified as chromosome specific, chromosome preferential, or chromosome nonspecific. Sequences which are classified as chromosome preferential are further sequenced and regions are identified having a low homology with other regions of the chromosome preferential sequence or with known sequences of other family me This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

Characterization of tannase protein sequences of bacteria and fungi: an in silico study.

PubMed

Banerjee, Amrita; Jana, Arijit; Pati, Bikash R; Mondal, Keshab C; Das Mohapatra, Pradeep K

2012-04-01

The tannase protein sequences of 149 bacteria and 36 fungi were retrieved from NCBI database. Among them only 77 bacterial and 31 fungal tannase sequences were taken which have different amino acid compositions. These sequences were analysed for different physical and chemical properties, superfamily search, multiple sequence alignment, phylogenetic tree construction and motif finding to find out the functional motif and the evolutionary relationship among them. The superfamily search for these tannase exposed the occurrence of proline iminopeptidase-like, biotin biosynthesis protein BioH, O-acetyltransferase, carboxylesterase/thioesterase 1, carbon-carbon bond hydrolase, haloperoxidase, prolyl oligopeptidase, C-terminal domain and mycobacterial antigens families and alpha/beta hydrolase superfamily. Some bacterial and fungal sequence showed similarity with different families individually. The multiple sequence alignment of these tannase protein sequences showed conserved regions at different stretches with maximum homology from amino acid residues 389-469 and 482-523 which could be used for designing degenerate primers or probes specific for tannase producing bacterial and fungal species. Phylogenetic tree showed two different clusters; one has only bacteria and another have both fungi and bacteria showing some relationship between these different genera. Although in second cluster near about all fungal species were found together in a corner which indicates the sequence level similarity among fungal genera. The distributions of fourteen motifs analysis revealed Motif 1 with a signature amino acid sequence of 29 amino acids, i.e. GCSTGGREALKQAQRWPHDYDGIIANNPA, was uniformly observed in 83.3 % of studied tannase sequences representing its participation with the structure and enzymatic function.

Assessment of Homology Templates and an Anesthetic Binding Site within the γ-Aminobutyric Acid Receptor

PubMed Central

Bertaccini, Edward J.; Yoluk, Ozge; Lindahl, Erik R.; Trudell, James R.

2013-01-01

Background Anesthetics mediate portions of their activity via modulation of the γ-aminobutyric acid receptor (GABAaR). While its molecular structure remains unknown, significant progress has been made towards understanding its interactions with anesthetics via molecular modeling. Methods The structure of the torpedo acetylcholine receptor (nAChRα), the structures of the α4 and β2 subunits of the human nAChR, the structures of the eukaryotic glutamate-gated chloride channel (GluCl), and the prokaryotic pH sensing channels, from Gloeobacter violaceus and Erwinia chrysanthemi, were aligned with the SAlign and 3DMA algorithms. A multiple sequence alignment from these structures and those of the GABAaR was performed with ClustalW. The Modeler and Rosetta algorithms independently created three-dimensional constructs of the GABAaR from the GluCl template. The CDocker algorithm docked a congeneric series of propofol derivatives into the binding pocket and scored calculated binding affinities for correlation with known GABAaR potentiation EC50’s. Results Multiple structure alignments of templates revealed a clear consensus of residue locations relevant to anesthetic effects except for torpedo nAChR. Within the GABAaR models generated from GluCl, the residues notable for modulating anesthetic action within transmembrane segments 1, 2, and 3 converged on the intersubunit interface between alpha and beta subunits. Docking scores of a propofol derivative series into this binding site showed strong linear correlation with GABAaR potentiation EC50. Conclusion Consensus structural alignment based on homologous templates revealed an intersubunit anesthetic binding cavity within the transmembrane domain of the GABAaR, which showed correlation of ligand docking scores with experimentally measured GABAaR potentiation. PMID:23770602

Assessment of homology templates and an anesthetic binding site within the γ-aminobutyric acid receptor.

PubMed

Bertaccini, Edward J; Yoluk, Ozge; Lindahl, Erik R; Trudell, James R

2013-11-01

Anesthetics mediate portions of their activity via modulation of the γ-aminobutyric acid receptor (GABAaR). Although its molecular structure remains unknown, significant progress has been made toward understanding its interactions with anesthetics via molecular modeling. The structure of the torpedo acetylcholine receptor (nAChRα), the structures of the α4 and β2 subunits of the human nAChR, the structures of the eukaryotic glutamate-gated chloride channel (GluCl), and the prokaryotic pH-sensing channels, from Gloeobacter violaceus and Erwinia chrysanthemi, were aligned with the SAlign and 3DMA algorithms. A multiple sequence alignment from these structures and those of the GABAaR was performed with ClustalW. The Modeler and Rosetta algorithms independently created three-dimensional constructs of the GABAaR from the GluCl template. The CDocker algorithm docked a congeneric series of propofol derivatives into the binding pocket and scored calculated binding affinities for correlation with known GABAaR potentiation EC50s. Multiple structure alignments of templates revealed a clear consensus of residue locations relevant to anesthetic effects except for torpedo nAChR. Within the GABAaR models generated from GluCl, the residues notable for modulating anesthetic action within transmembrane segments 1, 2, and 3 converged on the intersubunit interface between α and β subunits. Docking scores of a propofol derivative series into this binding site showed strong linear correlation with GABAaR potentiation EC50. Consensus structural alignment based on homologous templates revealed an intersubunit anesthetic binding cavity within the transmembrane domain of the GABAaR, which showed a correlation of ligand docking scores with experimentally measured GABAaR potentiation.

Sequences Of Amino Acids For Human Serum Albumin

NASA Technical Reports Server (NTRS)

Carter, Daniel C.

1992-01-01

Sequences of amino acids defined for use in making polypeptides one-third to one-sixth as large as parent human serum albumin molecule. Smaller, chemically stable peptides have diverse applications including service as artificial human serum and as active components of biosensors and chromatographic matrices. In applications involving production of artificial sera from new sequences, little or no concern about viral contaminants. Smaller genetically engineered polypeptides more easily expressed and produced in large quantities, making commercial isolation and production more feasible and profitable.

MetaGO: Predicting Gene Ontology of Non-homologous Proteins Through Low-Resolution Protein Structure Prediction and Protein-Protein Network Mapping.

PubMed

Zhang, Chengxin; Zheng, Wei; Freddolino, Peter L; Zhang, Yang

2018-03-10

Homology-based transferal remains the major approach to computational protein function annotations, but it becomes increasingly unreliable when the sequence identity between query and template decreases below 30%. We propose a novel pipeline, MetaGO, to deduce Gene Ontology attributes of proteins by combining sequence homology-based annotation with low-resolution structure prediction and comparison, and partner's homology-based protein-protein network mapping. The pipeline was tested on a large-scale set of 1000 non-redundant proteins from the CAFA3 experiment. Under the stringent benchmark conditions where templates with >30% sequence identity to the query are excluded, MetaGO achieves average F-measures of 0.487, 0.408, and 0.598, for Molecular Function, Biological Process, and Cellular Component, respectively, which are significantly higher than those achieved by other state-of-the-art function annotations methods. Detailed data analysis shows that the major advantage of the MetaGO lies in the new functional homolog detections from partner's homology-based network mapping and structure-based local and global structure alignments, the confidence scores of which can be optimally combined through logistic regression. These data demonstrate the power of using a hybrid model incorporating protein structure and interaction networks to deduce new functional insights beyond traditional sequence homology-based referrals, especially for proteins that lack homologous function templates. The MetaGO pipeline is available at http://zhanglab.ccmb.med.umich.edu/MetaGO/. Copyright © 2018. Published by Elsevier Ltd.

Comparative characterization of random-sequence proteins consisting of 5, 12, and 20 kinds of amino acids

PubMed Central

Tanaka, Junko; Doi, Nobuhide; Takashima, Hideaki; Yanagawa, Hiroshi

2010-01-01

Screening of functional proteins from a random-sequence library has been used to evolve novel proteins in the field of evolutionary protein engineering. However, random-sequence proteins consisting of the 20 natural amino acids tend to aggregate, and the occurrence rate of functional proteins in a random-sequence library is low. From the viewpoint of the origin of life, it has been proposed that primordial proteins consisted of a limited set of amino acids that could have been abundantly formed early during chemical evolution. We have previously found that members of a random-sequence protein library constructed with five primitive amino acids show high solubility (Doi et al., Protein Eng Des Sel 2005;18:279–284). Although such a library is expected to be appropriate for finding functional proteins, the functionality may be limited, because they have no positively charged amino acid. Here, we constructed three libraries of 120-amino acid, random-sequence proteins using alphabets of 5, 12, and 20 amino acids by preselection using mRNA display (to eliminate sequences containing stop codons and frameshifts) and characterized and compared the structural properties of random-sequence proteins arbitrarily chosen from these libraries. We found that random-sequence proteins constructed with the 12-member alphabet (including five primitive amino acids and positively charged amino acids) have higher solubility than those constructed with the 20-member alphabet, though other biophysical properties are very similar in the two libraries. Thus, a library of moderate complexity constructed from 12 amino acids may be a more appropriate resource for functional screening than one constructed from 20 amino acids. PMID:20162614

An ectromelia virus profilin homolog interacts with cellular tropomyosin and viral A-type inclusion protein.

PubMed

Butler-Cole, Christine; Wagner, Mary J; Da Silva, Melissa; Brown, Gordon D; Burke, Robert D; Upton, Chris

2007-07-24

Profilins are critical to cytoskeletal dynamics in eukaryotes; however, little is known about their viral counterparts. In this study, a poxviral profilin homolog, ectromelia virus strain Moscow gene 141 (ECTV-PH), was investigated by a variety of experimental and bioinformatics techniques to characterize its interactions with cellular and viral proteins. Profilin-like proteins are encoded by all orthopoxviruses sequenced to date, and share over 90% amino acid (aa) identity. Sequence comparisons show highest similarity to mammalian type 1 profilins; however, a conserved 3 aa deletion in mammalian type 3 and poxviral profilins suggests that these homologs may be more closely related. Structural analysis shows that ECTV-PH can be successfully modelled onto both the profilin 1 crystal structure and profilin 3 homology model, though few of the surface residues thought to be required for binding actin, poly(L-proline), and PIP2 are conserved. Immunoprecipitation and mass spectrometry identified two proteins that interact with ECTV-PH within infected cells: alpha-tropomyosin, a 38 kDa cellular actin-binding protein, and the 84 kDa product of vaccinia virus strain Western Reserve (VACV-WR) 148, which is the truncated VACV counterpart of the orthopoxvirus A-type inclusion (ATI) protein. Western and far-western blots demonstrated that the interaction with alpha-tropomyosin is direct, and immunofluorescence experiments suggest that ECTV-PH and alpha-tropomyosin may colocalize to structures that resemble actin tails and cellular protrusions. Sequence comparisons of the poxviral ATI proteins show that although full-length orthologs are only present in cowpox and ectromelia viruses, an ~ 700 aa truncated ATI protein is conserved in over 90% of sequenced orthopoxviruses. Immunofluorescence studies indicate that ECTV-PH localizes to cytoplasmic inclusion bodies formed by both truncated and full-length versions of the viral ATI protein. Furthermore, colocalization of ECTV-PH and

37 CFR 1.822 - Symbols and format to be used for nucleotide and/or amino acid sequence data.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for nucleotide and/or amino acid sequence data. 1.822 Section 1.822 Patents, Trademarks, and... Amino Acid Sequences § 1.822 Symbols and format to be used for nucleotide and/or amino acid sequence data. (a) The symbols and format to be used for nucleotide and/or amino acid sequence data shall...

Evaluation of targeted exome sequencing for 28 protein-based blood group systems, including the homologous gene systems, for blood group genotyping.

PubMed

Schoeman, Elizna M; Lopez, Genghis H; McGowan, Eunike C; Millard, Glenda M; O'Brien, Helen; Roulis, Eileen V; Liew, Yew-Wah; Martin, Jacqueline R; McGrath, Kelli A; Powley, Tanya; Flower, Robert L; Hyland, Catherine A

2017-04-01

Blood group single nucleotide polymorphism genotyping probes for a limited range of polymorphisms. This study investigated whether massively parallel sequencing (also known as next-generation sequencing), with a targeted exome strategy, provides an extended blood group genotype and the extent to which massively parallel sequencing correctly genotypes in homologous gene systems, such as RH and MNS. Donor samples (n = 28) that were extensively phenotyped and genotyped using single nucleotide polymorphism typing, were analyzed using the TruSight One Sequencing Panel and MiSeq platform. Genes for 28 protein-based blood group systems, GATA1, and KLF1 were analyzed. Copy number variation analysis was used to characterize complex structural variants in the GYPC and RH systems. The average sequencing depth per target region was 66.2 ± 39.8. Each sample harbored on average 43 ± 9 variants, of which 10 ± 3 were used for genotyping. For the 28 samples, massively parallel sequencing variant sequences correctly matched expected sequences based on single nucleotide polymorphism genotyping data. Copy number variation analysis defined the Rh C/c alleles and complex RHD hybrids. Hybrid RHD*D-CE-D variants were correctly identified, but copy number variation analysis did not confidently distinguish between D and CE exon deletion versus rearrangement. The targeted exome sequencing strategy employed extended the range of blood group genotypes detected compared with single nucleotide polymorphism typing. This single-test format included detection of complex MNS hybrid cases and, with copy number variation analysis, defined RH hybrid genes along with the RHCE*C allele hitherto difficult to resolve by variant detection. The approach is economical compared with whole-genome sequencing and is suitable for a red blood cell reference laboratory setting. © 2017 AABB.

37 CFR 1.823 - Requirements for nucleotide and/or amino acid sequences as part of the application.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and/or amino acid sequences as part of the application. 1.823 Section 1.823 Patents, Trademarks, and... Amino Acid Sequences § 1.823 Requirements for nucleotide and/or amino acid sequences as part of the... incorporation-by-reference of the Sequence Listing as required by § 1.52(e)(5). The presentation of the...

37 CFR 1.823 - Requirements for nucleotide and/or amino acid sequences as part of the application.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and/or amino acid sequences as part of the application. 1.823 Section 1.823 Patents, Trademarks, and... Amino Acid Sequences § 1.823 Requirements for nucleotide and/or amino acid sequences as part of the... incorporation-by-reference of the Sequence Listing as required by § 1.52(e)(5). The presentation of the...

37 CFR 1.823 - Requirements for nucleotide and/or amino acid sequences as part of the application.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and/or amino acid sequences as part of the application. 1.823 Section 1.823 Patents, Trademarks, and... Amino Acid Sequences § 1.823 Requirements for nucleotide and/or amino acid sequences as part of the... incorporation-by-reference of the Sequence Listing as required by § 1.52(e)(5). The presentation of the...

37 CFR 1.823 - Requirements for nucleotide and/or amino acid sequences as part of the application.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and/or amino acid sequences as part of the application. 1.823 Section 1.823 Patents, Trademarks, and... Amino Acid Sequences § 1.823 Requirements for nucleotide and/or amino acid sequences as part of the... incorporation-by-reference of the Sequence Listing as required by § 1.52(e)(5). The presentation of the...

37 CFR 1.823 - Requirements for nucleotide and/or amino acid sequences as part of the application.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and/or amino acid sequences as part of the application. 1.823 Section 1.823 Patents, Trademarks, and... Amino Acid Sequences § 1.823 Requirements for nucleotide and/or amino acid sequences as part of the... incorporation-by-reference of the Sequence Listing as required by § 1.52(e)(5). The presentation of the...

Girardia dorotocephala transcriptome sequence, assembly, and validation through characterization of piwi homologs and stem cell progeny markers.

PubMed

Almazan, Eugene Matthew P; Lesko, Sydney L; Markey, Michael P; Rouhana, Labib

2018-01-15

Planarian flatworms are popular models for the study of regeneration and stem cell biology in vivo. Technical advances and increased availability of genetic information have fueled the discovery of molecules responsible for stem cell pluripotency and regeneration in flatworms. Unfortunately, most of the planarian research performed worldwide utilizes species that are not natural habitants of North America, which limits their availability to newcomer laboratories and impedes their distribution for educational activities. In order to circumvent these limitations and increase the genetic information available for comparative studies, we sequenced the transcriptome of Girardia dorotocephala, a planarian species pandemic and commercially available in North America. A total of 254,802,670 paired sequence reads were obtained from RNA extracted from intact individuals, regenerating fragments, as well as freshly excised auricles of a clonal line of G. dorotocephala (MA-C2), and used for de novo assembly of its transcriptome. The resulting transcriptome draft was validated through functional analysis of genetic markers of stem cells and their progeny in G. dorotocephala. Akin to orthologs in other planarian species, G. dorotocephala Piwi1 (GdPiwi1) was found to be a robust marker of the planarian stem cell population and GdPiwi2 an essential component for stem cell-driven regeneration. Identification of G. dorotocephala homologs of the early stem cell descendent marker PROG-1 revealed a family of lysine-rich proteins expressed during epithelial cell differentiation. Sequences from the MA-C2 transcriptome were found to be 98-99% identical to nucleotide sequences from G. dorotocephala populations with different chromosomal number, demonstrating strong conservation regardless of karyotype evolution. Altogether, this work establishes G. dorotocephala as a viable and accessible option for analysis of gene function in North America. Copyright © 2017 The Authors. Published by

Girardia dorotocephala transcriptome sequence, assembly, and validation through characterization of piwi homologs and stem cell progeny markers

PubMed Central

Almazan, Eugene Matthew P.; Lesko, Sydney L.; Markey, Michael P.; Rouhana, Labib

2017-01-01

Planarian flatworms are popular models for the study of regeneration and stem cell biology in vivo. Technical advances and increased availability of genetic information have fueled the discovery of molecules responsible for stem cell pluripotency and regeneration in flatworms. Unfortunately, most of the planarian research performed worldwide utilizes species that are not natural habitants of North America, which limits their availability to newcomer laboratories and impedes their distribution for educational activities. In order to circumvent these limitations and increase the genetic information available for comparative studies, we sequenced the transcriptome of Girardia dorotocephala, a planarian species pandemic and commercially available in North America. A total of 254,802,670 paired sequence reads were obtained from RNA extracted from intact individuals, regenerating fragments, as well as freshly excised auricles of a clonal line of G. dorotocephala (MA-C2), and used for de novo assembly of its transcriptome. The resulting transcriptome draft was validated through functional analysis of genetic markers of stem cells and their progeny in G. dorotocephala. Akin to orthologs in other planarian species, G. dorotocephala Piwi1 (GdPiwi1) was found to be a robust marker of the planarian stem cell population and GdPiwi2 an essential component for stem cell-driven regeneration. Identification of G. dorotocephala homologs of the early stem cell descendent marker PROG-1 revealed a family of lysine-rich proteins expressed during epithelial cell differentiation. Sequences from the MA-C2 transcriptome were found to be 98–99% identical to nucleotide sequences from G. dorotocephala populations with different chromosomal number, demonstrating strong conservation regardless of karyotype evolution. Altogether, this work establishes G. dorotocephala as a viable and accessible option for analysis of gene function in North America. PMID:28774726

Nucleotide sequence analysis of the gene encoding the Deinococcus radiodurans surface protein, derived amino acid sequence, and complementary protein chemical studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, J.; Peters, M.; Lottspeich, F.

1987-11-01

The complete nucleotide sequence of the gene encoding the surface (hexagonally packed intermediate (HPI))-layer polypeptide of Deinococcus radiodurans Sark was determined and found to encode a polypeptide of 1036 amino acids. Amino acid sequence analysis of about 30% of the residues revealed that the mature polypeptide consists of at least 978 amino acids. The N terminus was blocked to Edman degradation. The results of proteolytic modification of the HPI layer in situ and M/sub r/ estimations of the HPI polypeptide expressed in Escherichia coli indicated that there is a leader sequence. The N-terminal region contained a very high percentage (29%)more » of threonine and serine, including a cluster of nine consecutive serine or threonine residues, whereas a stretch near the C terminus was extremely rich in aromatic amino acids (29%). The protein contained at least two disulfide bridges, as well as tightly bound reducing sugars and fatty acids.« less

Sequencing, Analysis, and Annotation of Expressed Sequence Tags for Camelus dromedarius

PubMed Central

Al-Swailem, Abdulaziz M.; Shehata, Maher M.; Abu-Duhier, Faisel M.; Al-Yamani, Essam J.; Al-Busadah, Khalid A.; Al-Arawi, Mohammed S.; Al-Khider, Ali Y.; Al-Muhaimeed, Abdullah N.; Al-Qahtani, Fahad H.; Manee, Manee M.; Al-Shomrani, Badr M.; Al-Qhtani, Saad M.; Al-Harthi, Amer S.; Akdemir, Kadir C.; Otu, Hasan H.

2010-01-01

Despite its economical, cultural, and biological importance, there has not been a large scale sequencing project to date for Camelus dromedarius. With the goal of sequencing complete DNA of the organism, we first established and sequenced camel EST libraries, generating 70,272 reads. Following trimming, chimera check, repeat masking, cluster and assembly, we obtained 23,602 putative gene sequences, out of which over 4,500 potentially novel or fast evolving gene sequences do not carry any homology to other available genomes. Functional annotation of sequences with similarities in nucleotide and protein databases has been obtained using Gene Ontology classification. Comparison to available full length cDNA sequences and Open Reading Frame (ORF) analysis of camel sequences that exhibit homology to known genes show more than 80% of the contigs with an ORF>300 bp and ∼40% hits extending to the start codons of full length cDNAs suggesting successful characterization of camel genes. Similarity analyses are done separately for different organisms including human, mouse, bovine, and rat. Accompanying web portal, CAGBASE (http://camel.kacst.edu.sa/), hosts a relational database containing annotated EST sequences and analysis tools with possibility to add sequences from public domain. We anticipate our results to provide a home base for genomic studies of camel and other comparative studies enabling a starting point for whole genome sequencing of the organism. PMID:20502665

A Comprehensive Strategy for Accurate Mutation Detection of the Highly Homologous PMS2.

PubMed

Li, Jianli; Dai, Hongzheng; Feng, Yanming; Tang, Jia; Chen, Stella; Tian, Xia; Gorman, Elizabeth; Schmitt, Eric S; Hansen, Terah A A; Wang, Jing; Plon, Sharon E; Zhang, Victor Wei; Wong, Lee-Jun C

2015-09-01

Germline mutations in the DNA mismatch repair gene PMS2 underlie the cancer susceptibility syndrome, Lynch syndrome. However, accurate molecular testing of PMS2 is complicated by a large number of highly homologous sequences. To establish a comprehensive approach for mutation detection of PMS2, we have designed a strategy combining targeted capture next-generation sequencing (NGS), multiplex ligation-dependent probe amplification, and long-range PCR followed by NGS to simultaneously detect point mutations and copy number changes of PMS2. Exonic deletions (E2 to E9, E5 to E9, E8, E10, E14, and E1 to E15), duplications (E11 to E12), and a nonsense mutation, p.S22*, were identified. Traditional multiplex ligation-dependent probe amplification and Sanger sequencing approaches cannot differentiate the origin of the exonic deletions in the 3' region when PMS2 and PMS2CL share identical sequences as a result of gene conversion. Our approach allows unambiguous identification of mutations in the active gene with a straightforward long-range-PCR/NGS method. Breakpoint analysis of multiple samples revealed that recurrent exon 14 deletions are mediated by homologous Alu sequences. Our comprehensive approach provides a reliable tool for accurate molecular analysis of genes containing multiple copies of highly homologous sequences and should improve PMS2 molecular analysis for patients with Lynch syndrome. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Finding similar nucleotide sequences using network BLAST searches.

PubMed

Ladunga, Istvan

2009-06-01

The Basic Local Alignment Search Tool (BLAST) is a keystone of bioinformatics due to its performance and user-friendliness. Beginner and intermediate users will learn how to design and submit blastn and Megablast searches on the Web pages at the National Center for Biotechnology Information. We map nucleic acid sequences to genomes, find identical or similar mRNA, expressed sequence tag, and noncoding RNA sequences, and run Megablast searches, which are much faster than blastn. Understanding results is assisted by taxonomy reports, genomic views, and multiple alignments. We interpret expected frequency thresholds, biological significance, and statistical significance. Weak hits provide no evidence, but hints for further analyses. We find genes that may code for homologous proteins by translated BLAST. We reduce false positives by filtering out low-complexity regions. Parsed BLAST results can be integrated into analysis pipelines. Links in the output connect to Entrez, PUBMED, structural, sequence, interaction, and expression databases. This facilitates integration with a wide spectrum of biological knowledge.

Restriction and Sequence Alterations Affect DNA Uptake Sequence-Dependent Transformation in Neisseria meningitidis

PubMed Central

Ambur, Ole Herman; Frye, Stephan A.; Nilsen, Mariann; Hovland, Eirik; Tønjum, Tone

2012-01-01

Transformation is a complex process that involves several interactions from the binding and uptake of naked DNA to homologous recombination. Some actions affect transformation favourably whereas others act to limit it. Here, meticulous manipulation of a single type of transforming DNA allowed for quantifying the impact of three different mediators of meningococcal transformation: NlaIV restriction, homologous recombination and the DNA Uptake Sequence (DUS). In the wildtype, an inverse relationship between the transformation frequency and the number of NlaIV restriction sites in DNA was observed when the transforming DNA harboured a heterologous region for selection (ermC) but not when the transforming DNA was homologous with only a single nucleotide heterology. The influence of homologous sequence in transforming DNA was further studied using plasmids with a small interruption or larger deletions in the recombinogenic region and these alterations were found to impair transformation frequency. In contrast, a particularly potent positive driver of DNA uptake in Neisseria sp. are short DUS in the transforming DNA. However, the molecular mechanism(s) responsible for DUS specificity remains unknown. Increasing the number of DUS in the transforming DNA was here shown to exert a positive effect on transformation. Furthermore, an influence of variable placement of DUS relative to the homologous region in the donor DNA was documented for the first time. No effect of altering the orientation of DUS was observed. These observations suggest that DUS is important at an early stage in the recognition of DNA, but does not exclude the existence of more than one level of DUS specificity in the sequence of events that constitute transformation. New knowledge on the positive and negative drivers of transformation may in a larger perspective illuminate both the mechanisms and the evolutionary role(s) of one of the most conserved mechanisms in nature: homologous recombination. PMID

Directed alteration of Saccharomyces cerevisiae mitochondrial DNA by biolistic transformation and homologous recombination.

PubMed

Bonnefoy, Nathalie; Fox, Thomas D

2007-01-01

Saccharomyces cerevisiae is currently the only species in which genetic transformation of mitochondria can be used to generate a wide variety of defined alterations in mitochondrial deoxyribonucleic acid (mtDNA). DNA sequences can be delivered into yeast mitochondria by microprojectile bombardment (biolistic transformation) and subsequently incorporated into mtDNA by the highly active homologous recombination machinery present in the organelle. Although transformation frequencies are relatively low, the availability of strong mitochondrial selectable markers for the yeast system, both natural and synthetic, makes the isolation of transformants routine. The strategies and procedures reviewed here allow the researcher to insert defined mutations into endogenous mitochondrial genes and to insert new genes into mtDNA. These methods provide powerful in vivo tools for the study of mitochondrial biology.

MultiSeq: unifying sequence and structure data for evolutionary analysis

PubMed Central

Roberts, Elijah; Eargle, John; Wright, Dan; Luthey-Schulten, Zaida

2006-01-01

Background Since the publication of the first draft of the human genome in 2000, bioinformatic data have been accumulating at an overwhelming pace. Currently, more than 3 million sequences and 35 thousand structures of proteins and nucleic acids are available in public databases. Finding correlations in and between these data to answer critical research questions is extremely challenging. This problem needs to be approached from several directions: information science to organize and search the data; information visualization to assist in recognizing correlations; mathematics to formulate statistical inferences; and biology to analyze chemical and physical properties in terms of sequence and structure changes. Results Here we present MultiSeq, a unified bioinformatics analysis environment that allows one to organize, display, align and analyze both sequence and structure data for proteins and nucleic acids. While special emphasis is placed on analyzing the data within the framework of evolutionary biology, the environment is also flexible enough to accommodate other usage patterns. The evolutionary approach is supported by the use of predefined metadata, adherence to standard ontological mappings, and the ability for the user to adjust these classifications using an electronic notebook. MultiSeq contains a new algorithm to generate complete evolutionary profiles that represent the topology of the molecular phylogenetic tree of a homologous group of distantly related proteins. The method, based on the multidimensional QR factorization of multiple sequence and structure alignments, removes redundancy from the alignments and orders the protein sequences by increasing linear dependence, resulting in the identification of a minimal basis set of sequences that spans the evolutionary space of the homologous group of proteins. Conclusion MultiSeq is a major extension of the Multiple Alignment tool that is provided as part of VMD, a structural visualization program for

Amino acid sequence of tyrosinase from Neurospora crassa.

PubMed Central

Lerch, K

1978-01-01

The amino-acid sequence of tyrosinase from Neurospora crassa (monophenol,dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) is reported. This copper-containing oxidase consists of a single polypeptide chain of 407 amino acids. The primary structure was determined by automated and manual sequence analysis on fragments produced by cleavage with cyanogen bromide and on peptides obtained by digestion with trypsin, pepsin, thermolysin, or chymotrypsin. The amino terminus of the protein is acetylated and the single cysteinyl residue 96 is covalently linked via a thioether bridge to histidyl residue 94. The formation and the possible role of this unusual structure in Neurospora tyrosinase is discussed. Dye-sensitized photooxidation of apotyrosinase and active-site-directed inactivation of the native enzyme indicate the possible involvement of histidyl residues 188, 192, 289, and 305 or 306 as ligands to the active-site copper as well as in the catalytic mechanism of this monooxygenase. PMID:151279

The primary structure of rat liver ribosomal protein L37. Homology with yeast and bacterial ribosomal proteins.

PubMed

Lin, A; McNally, J; Wool, I G

1983-09-10

The covalent structure of the rat liver 60 S ribosomal subunit protein L37 was determined. Twenty-four tryptic peptides were purified and the sequence of each was established; they accounted for all 111 residues of L37. The sequence of the first 30 residues of L37, obtained previously by automated Edman degradation of the intact protein, provided the alignment of the first 9 tryptic peptides. Three peptides (CN1, CN2, and CN3) were produced by cleavage of protein L37 with cyanogen bromide. The sequence of CN1 (65 residues) was established from the sequence of secondary peptides resulting from cleavage with trypsin and chymotrypsin. The sequence of CN1 in turn served to order tryptic peptides 1 through 14. The sequence of CN2 (15 residues) was determined entirely by a micromanual procedure and allowed the alignment of tryptic peptides 14 through 18. The sequence of the NH2-terminal 28 amino acids of CN3 (31 residues) was determined; in addition the complete sequences of the secondary tryptic and chymotryptic peptides were done. The sequence of CN3 provided the order of tryptic peptides 18 through 24. Thus the sequence of the three cyanogen bromide peptides also accounted for the 111 residues of protein L37. The carboxyl-terminal amino acids were identified after carboxypeptidase A treatment. There is a disulfide bridge between half-cystinyl residues at positions 40 and 69. Rat liver ribosomal protein L37 is homologous with yeast YP55 and with Escherichia coli L34. Moreover, there is a segment of 17 residues in rat L37 that occurs, albeit with modifications, in yeast YP55 and in E. coli S4, L20, and L34.

Molecular cloning and sequence analysis of full-length growth hormone cDNAs from six important economic fishes.

PubMed

Zhang, Jing-Nan; Song, Ping; Hu, Jia-Rui; Mo, Sai-Jun; Peng, Mao-Yu; Zhou, Wei; Zou, Ji-Xing; Hu, Yin-Chang

2005-01-01

In this study,the full-length cDNAs of GH (Growth Hormone) gene was isolated from six important economic fishes, Siniperca kneri, Epinephelus coioides, Monopterus albus, Silurus asotus, Misgurnus anguillicaudatus and Carassius auratus gibelio Bloch. It is the first time to clone these GH sequences except E. coioides GH. The lengths of the above cDNAs are as follows: 953 bp, 1 023 bp, 825 bp, 1 082 bp, 1 154 bp and 1 180 bp. Each sequence includes an ORF of about 600 bp which encodes a protein of about 200 amino acid: S. kneri, E. coioides and M. albus GHs of 204 amino acid, S. asotus GH of 200 amino acid, M. anguillicaudatus and C. auratus gibelio GHs of 210 amino acid. Then detailed sequence analysis of the six GHs with many other fish sequences was performed. The six sequences all showed high homology to other sequences, especially to sequences within the same order, and many conserved residues were identified, most localized in five domains. The phylogenetic trees (MP and NJ) of many fish GH ORF sequences (including the new six) with Amia calva as outgroup were generally resolved and largely congruent with the morphology-based tree though some incongruities were observed, suggesting GH ORF should be paid more attention to in teleostean phylogeny.

Better Understanding of Homologous Recombination through a 12-Week Laboratory Course for Undergraduates Majoring in Biotechnology

ERIC Educational Resources Information Center

Li, Ming; Shen, Xiaodong; Zhao, Yan; Hu, Xiaomei; Hu, Fuquan; Rao, Xiancai

2017-01-01

Homologous recombination, a central concept in biology, is defined as the exchange of DNA strands between two similar or identical nucleotide sequences. Unfortunately, undergraduate students majoring in biotechnology often experience difficulties in understanding the molecular basis of homologous recombination. In this study, we developed and…

Mapping neurofibromatosis 1 homologous loci by fluorescence in situ hybridization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Viskochil, D.; Breidenbach, H.H.; Cawthon, R.

Neurofibromatosis 1 maps to chromosome band 17q11.2 and the NF1 gene is comprised of 59 exons that span approximately 335 kb of genomic DNA. In order to further analyze the structure of NF1 from exons 2 through 27b, we isolated a number of cosmid and bacteriophage P-1 genomic clones using NF1-exon probes under high-stringency hybridization conditions. Using tagged, intron-based primers and DNA from various clones as a template, we PCR-amplified and sequenced individual NF1 exons. The exon sequences in PCR products from several genomic clones differed from the exon sequence derived from cloned NF1 cDNAs. Clones with variant sequences weremore » mapped by fluorescence in situ hybridization under high-stringency conditions. Three clones mapped to chromosome band 15q11.2, one mapped to 14q11.2, one mapped to both 2q14.1-14.3 and 14q11.2, one mapped to 2q33-34, and one mapped to both 18q11.2 and 21q21. Even though some PCR-product sequences retained proper splice junctions and open reading frames, we have yet to identify cDNAs that correspond to the variant exon sequences. We are now sequencing clones that map to NF1-homologous loci in order to develop discriminating primer pairs for the exclusive amplification of NF1-specific sequences in our efforts to develop a comprehensive NF1 mutation screen using genomic DNA as template. The role of NF1-homologous sequences may play in neurofibromatosis 1 is not clear.« less

Comparative analyses of putative toxin gene homologs from an Old World viper, Daboia russelii

PubMed Central

Krishnan, Neeraja M.

2017-01-01

Availability of snake genome sequences has opened up exciting areas of research on comparative genomics and gene diversity. One of the challenges in studying snake genomes is the acquisition of biological material from live animals, especially from the venomous ones, making the process cumbersome and time-consuming. Here, we report comparative sequence analyses of putative toxin gene homologs from Russell’s viper (Daboia russelii) using whole-genome sequencing data obtained from shed skin. When compared with the major venom proteins in Russell’s viper studied previously, we found 45–100% sequence similarity between the venom proteins and their putative homologs in the skin. Additionally, comparative analyses of 20 putative toxin gene family homologs provided evidence of unique sequence motifs in nerve growth factor (NGF), platelet derived growth factor (PDGF), Kunitz/Bovine pancreatic trypsin inhibitor (Kunitz BPTI), cysteine-rich secretory proteins, antigen 5, andpathogenesis-related1 proteins (CAP) and cysteine-rich secretory protein (CRISP). In those derived proteins, we identified V11 and T35 in the NGF domain; F23 and A29 in the PDGF domain; N69, K2 and A5 in the CAP domain; and Q17 in the CRISP domain to be responsible for differences in the largest pockets across the protein domain structures in crotalines, viperines and elapids from the in silico structure-based analysis. Similarly, residues F10, Y11 and E20 appear to play an important role in the protein structures across the kunitz protein domain of viperids and elapids. Our study highlights the usefulness of shed skin in obtaining good quality high-molecular weight DNA for comparative genomic studies, and provides evidence towards the unique features and evolution of putative venom gene homologs in vipers. PMID:29230357

Vital Roles of the Second DNA-binding Site of Rad52 Protein in Yeast Homologous Recombination*

PubMed Central

Arai, Naoto; Kagawa, Wataru; Saito, Kengo; Shingu, Yoshinori; Mikawa, Tsutomu; Kurumizaka, Hitoshi; Shibata, Takehiko

2011-01-01

RecA/Rad51 proteins are essential in homologous DNA recombination and catalyze the ATP-dependent formation of D-loops from a single-stranded DNA and an internal homologous sequence in a double-stranded DNA. RecA and Rad51 require a “recombination mediator” to overcome the interference imposed by the prior binding of single-stranded binding protein/replication protein A to the single-stranded DNA. Rad52 is the prototype of recombination mediators, and the human Rad52 protein has two distinct DNA-binding sites: the first site binds to single-stranded DNA, and the second site binds to either double- or single-stranded DNA. We previously showed that yeast Rad52 extensively stimulates Rad51-catalyzed D-loop formation even in the absence of replication protein A, by forming a 2:1 stoichiometric complex with Rad51. However, the precise roles of Rad52 and Rad51 within the complex are unknown. In the present study, we constructed yeast Rad52 mutants in which the amino acid residues corresponding to the second DNA-binding site of the human Rad52 protein were replaced with either alanine or aspartic acid. We found that the second DNA-binding site is important for the yeast Rad52 function in vivo. Rad51-Rad52 complexes consisting of these Rad52 mutants were defective in promoting the formation of D-loops, and the ability of the complex to associate with double-stranded DNA was specifically impaired. Our studies suggest that Rad52 within the complex associates with double-stranded DNA to assist Rad51-mediated homologous pairing. PMID:21454474

Homology modeling and prediction of the amino acid residues participating in the transfer of acetyl-CoA to arylalkylamine by the N-acetyltransferase from Chryseobacterium sp.

PubMed

Takenaka, Shinji; Ozeki, Takahiro; Tanaka, Kosei; Yoshida, Ken-Ichi

2017-11-01

To predict the amino acid residues playing important roles in acetyl-CoA and substrate binding and to study the acetyl group transfer mechanism of Chryseobacterium sp. 5-3B N-acetyltransferase (5-3B NatA). A 3-dimensional homology model of 5-3B NatA was constructed to compare the theoretical structure of this compound with the structures of previously reported proteins belonging to the bacterial GCN5 N-acetyltransferase family. Homology modeling of the 5-3B NatA structure and a characterization of the enzyme's kinetic parameters identified the essential amino acid residues involved in binding and acetyl-group transfer. 126 Leu, 132 Leu, and 135 Lys were implicated in the binding of phosphopantothenic acid, and 100 Tyr and 131 Lys in that of adenosyl biphosphate. The data supported the participation of 83 Glu and 133 Tyr in catalyzing acetyl-group transfer to L-2-phenylglycine. 5-3B NatA catalyzes the enantioselective N-acetylation of L-2-phenylglycine via a ternary complex comprising the enzyme, acetyl-CoA, and the substrate.

Nanopores and nucleic acids: prospects for ultrarapid sequencing

NASA Technical Reports Server (NTRS)

Deamer, D. W.; Akeson, M.

2000-01-01

DNA and RNA molecules can be detected as they are driven through a nanopore by an applied electric field at rates ranging from several hundred microseconds to a few milliseconds per molecule. The nanopore can rapidly discriminate between pyrimidine and purine segments along a single-stranded nucleic acid molecule. Nanopore detection and characterization of single molecules represents a new method for directly reading information encoded in linear polymers. If single-nucleotide resolution can be achieved, it is possible that nucleic acid sequences can be determined at rates exceeding a thousand bases per second.

Identification of the homolog of cell-counting factor in the cellular slime mold Dictyostelium discoideum.

PubMed

Okuwa, Takako; Katayama, Takahiro; Takano, Akinori; Yasukawa, Hiroo

2002-10-01

Genes for the cell-counting factors in Dictyostelium discoideum, countin and countin2, are considered to control the size of the multicellular structure of this organism. A novel gene, countin3, that is homologous to countin and countin2 genes (49 and 39% identity in amino acid sequence, respectively) was identified in the D. discoideum genome. The expression of countin3 was observed in the vegetatively growing cells, decreased in the aggregating stage, increased in the mid-developmental stage and decreased again in subsequent stages. This expression pattern is different from that of countin and countin2. The distinct expression kinetics of three genes suggests that they would have unique roles in size control of D. discoideum.

Sequencing BPS spectra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gukov, Sergei; Nawata, Satoshi; Saberi, Ingmar

In this article, we provide both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explainmore » from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincar e polynomials in numerous examples. Among these structural properties is a novel "sliding" property, which can be explained by using (re fined) modular S-matrix. This leads to the identi fication of modular transformations in Chern-Simons theory and 3d N = 2 theory via the 3d/3d correspondence. In conclusion, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.« less

Sequencing BPS spectra

DOE PAGES

Gukov, Sergei; Nawata, Satoshi; Saberi, Ingmar; ...

2016-03-02

In this article, we provide both a detailed study of color-dependence of link homologies, as realized in physics as certain spaces of BPS states, and a broad study of the behavior of BPS states in general. We consider how the spectrum of BPS states varies as continuous parameters of a theory are perturbed. This question can be posed in a wide variety of physical contexts, and we answer it by proposing that the relationship between unperturbed and perturbed BPS spectra is described by a spectral sequence. These general considerations unify previous applications of spectral sequence techniques to physics, and explainmore » from a physical standpoint the appearance of many spectral sequences relating various link homology theories to one another. We also study structural properties of colored HOMFLY homology for links and evaluate Poincar e polynomials in numerous examples. Among these structural properties is a novel "sliding" property, which can be explained by using (re fined) modular S-matrix. This leads to the identi fication of modular transformations in Chern-Simons theory and 3d N = 2 theory via the 3d/3d correspondence. In conclusion, we introduce the notion of associated varieties as classical limits of recursion relations of colored superpolynomials of links, and study their properties.« less

PubDNA Finder: a web database linking full-text articles to sequences of nucleic acids.

PubMed

García-Remesal, Miguel; Cuevas, Alejandro; Pérez-Rey, David; Martín, Luis; Anguita, Alberto; de la Iglesia, Diana; de la Calle, Guillermo; Crespo, José; Maojo, Víctor

2010-11-01

PubDNA Finder is an online repository that we have created to link PubMed Central manuscripts to the sequences of nucleic acids appearing in them. It extends the search capabilities provided by PubMed Central by enabling researchers to perform advanced searches involving sequences of nucleic acids. This includes, among other features (i) searching for papers mentioning one or more specific sequences of nucleic acids and (ii) retrieving the genetic sequences appearing in different articles. These additional query capabilities are provided by a searchable index that we created by using the full text of the 176 672 papers available at PubMed Central at the time of writing and the sequences of nucleic acids appearing in them. To automatically extract the genetic sequences occurring in each paper, we used an original method we have developed. The database is updated monthly by automatically connecting to the PubMed Central FTP site to retrieve and index new manuscripts. Users can query the database via the web interface provided. PubDNA Finder can be freely accessed at http://servet.dia.fi.upm.es:8080/pubdnafinder

Expression of the Pasteurella haemolytica leukotoxin is inhibited by a locus that encodes an ATP-binding cassette homolog.

PubMed Central

Highlander, S K; Wickersham, E A; Garza, O; Weinstock, G M

1993-01-01

Multicopy and single-copy chromosomal fusions between the Pasteurella haemolytica leukotoxin regulatory region and the Escherichia coli beta-galactosidase gene have been constructed. These fusions were used as reporters to identify and isolate regulators of leukotoxin expression from a P. haemolytica cosmid library. A cosmid clone, which inhibited leukotoxin expression from multicopy and single-copy protein fusions, was isolated and found to contain the complete leukotoxin gene cluster plus additional upstream sequences. The locus responsible for inhibition of expression from leukotoxin-beta-galactosidase fusions was mapped within these upstream sequences, by transposon mutagenesis with Tn5, and its DNA sequence was determined. The inhibitory activity was found to be associated with a predicted 440-amino-acid reading frame (lapA) that lies within a four-gene arginine transport locus. LapA is predicted to be the nucleotide-binding component of this transport system and shares homology with the Clp family of proteases. Images PMID:8359916

Homologies between the amino acid sequences of some vertebrate peptide hormones and peptides isolated from invertebrate sources.

PubMed

De Loof, A; Schoofs, L

1990-01-01

1. The 4K-prothoracicotropic hormone (PTTH) or bombyxin and the melanization-reddish coloration hormone of the silkworm Bombyx mori resemble insulin and insulin-like growth factors. 2. The family of adipokinetic/red pigment concentrating hormones has some similarity with glucagon. 3. Members of the FMRFamide family are found in vertebrates as well as in invertebrates. 4. In Locusta, a molecule immunologically and biologically related to amphibian melanophore stimulating hormone has been partially characterized. 5. Enkephalins and enkephalin-related peptides occur in insects and other invertebrates. 6. Peptides belonging to the tachykinin family have been isolated from molluscan (Octopus) salivary glands and from insect nervous tissue (Locusta migratoria). 7. Invertebrate arginine-vasotocin homologs have been isolated from an insect (Locusta migratoria) and from a mollusc (Conus). 8. In Leucophaea, Locusta and Drosophila, peptides resembling those of the vertebrate gastrin/cholecystokinin family have been identified. 9. As the number of different neuro-/gut peptides with possible function(s) as hormone, neurotransmitter or neuromodulator is now estimated to be of the order of a few hundred, more similarities will probably show up in the near future.

Molecular association of normal alkanoic acids with their thallium(I) salts: a new homologous series of fatty acid metal soaps.

PubMed

Fernández-García, M; García, M V; Redondo, M I; Cheda, J A; Fernández-García, M; Westrum, E F; Fernández-Martín, F

1997-02-01

A new homologous series of thallium(I) hydrogen dialkanoates, fatty acid thallium soaps, from the dipropane up to the ditetradecane is reported for the first time. This association with 1:1 stoichiometry is the only one exhibited by the thallium derivatives. They have been prepared by solidification of molten mixtures with equimolar proportions of acid and corresponding neutral salt, through crystallization from an anhydrous ethanolic solution of the mixture has also been successful in getting pure compounds with largest chain lengths. Vibrational spectroscopies clearly characterize these crystalline compounds as very strong hydrogen bonding systems. Assignations of active modes in proton and carbon nuclear magnetic resonance spectrometry (NMR) (in ethanol) and infrared (IR) and Raman spectra (in solid state) are reported. According to X-ray diffraction (XRD) they have monomolecular lamellar structures with the acyl chains arranged up and down to the cation/H-bond network in a methyl-to-methyl fashion, and vertically oriented to the basal plane. The acyl chains present all-trans conformation and alternating configuration (perpendicular orthorhombic subcell), like the beta'-phases of other kinds of lipids. Lamellar thickness is reported for the six room-temperature crystalline members. The molecular compounds present polymorphism, one crystal/crystal transition at temperatures close to the peritectical melting. Phase transition thermodynamics are also given and discussed with respect to their acid and salt parents. Their incongruent melting involves nearly 90% of the total enthalpic increments of both constituents' melting processes, making these compounds potential thermal energy storage materials.

BLAST and FASTA similarity searching for multiple sequence alignment.

PubMed

Pearson, William R

2014-01-01

BLAST, FASTA, and other similarity searching programs seek to identify homologous proteins and DNA sequences based on excess sequence similarity. If two sequences share much more similarity than expected by chance, the simplest explanation for the excess similarity is common ancestry-homology. The most effective similarity searches compare protein sequences, rather than DNA sequences, for sequences that encode proteins, and use expectation values, rather than percent identity, to infer homology. The BLAST and FASTA packages of sequence comparison programs provide programs for comparing protein and DNA sequences to protein databases (the most sensitive searches). Protein and translated-DNA comparisons to protein databases routinely allow evolutionary look back times from 1 to 2 billion years; DNA:DNA searches are 5-10-fold less sensitive. BLAST and FASTA can be run on popular web sites, but can also be downloaded and installed on local computers. With local installation, target databases can be customized for the sequence data being characterized. With today's very large protein databases, search sensitivity can also be improved by searching smaller comprehensive databases, for example, a complete protein set from an evolutionarily neighboring model organism. By default, BLAST and FASTA use scoring strategies target for distant evolutionary relationships; for comparisons involving short domains or queries, or searches that seek relatively close homologs (e.g. mouse-human), shallower scoring matrices will be more effective. Both BLAST and FASTA provide very accurate statistical estimates, which can be used to reliably identify protein sequences that diverged more than 2 billion years ago.

Complete complementary DNA-derived amino acid sequence of canine cardiac phospholamban.

PubMed Central

Fujii, J; Ueno, A; Kitano, K; Tanaka, S; Kadoma, M; Tada, M

1987-01-01

Complementary DNA (cDNA) clones specific for phospholamban of sarcoplasmic reticulum membranes have been isolated from a canine cardiac cDNA library. The amino acid sequence deduced from the cDNA sequence indicates that phospholamban consists of 52 amino acid residues and lacks an amino-terminal signal sequence. The protein has an inferred mol wt 6,080 that is in agreement with its apparent monomeric mol wt 6,000, estimated previously by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Phospholamban contains two distinct domains, a hydrophilic region at the amino terminus (domain I) and a hydrophobic region at the carboxy terminus (domain II). We propose that domain I is localized at the cytoplasmic surface and offers phosphorylatable sites whereas domain II is anchored into the sarcoplasmic reticulum membrane. PMID:3793929

The nucleotide sequence of a segment of Trypanosoma brucei mitochondrial maxi-circle DNA that contains the gene for apocytochrome b and some unusual unassigned reading frames.

PubMed Central

Benne, R; De Vries, B F; Van den Burg, J; Klaver, B

1983-01-01

The nucleotide sequence of a 2.5-kb segment of the maxi-circle of Trypanosoma brucei mtDNA has been determined. The segment contains the gene for apocytochrome b, which displays about 25% homology at the amino acid level to the apocytochrome b gene from fungal and mammalian mtDNAs. Northern blot and S1 nuclease analyses have yielded accurate map positions of an RNA species in an area that coincides with the reading frame. The segment also contains two pairs of overlapping unassigned reading frames, which lack homology with any known mitochondrial gene or URF. The DNA sequence in these areas is AG-rich (70%), resulting in URFs with an unusually high level of glycine and charged amino acids (60%). They may not encode proteins, in spite of their size and the fact that abundant transcripts are mapped in these areas. Images PMID:6314266

Bhageerath-H: A homology/ab initio hybrid server for predicting tertiary structures of monomeric soluble proteins

PubMed Central

2014-01-01

Background The advent of human genome sequencing project has led to a spurt in the number of protein sequences in the databanks. Success of structure based drug discovery severely hinges on the availability of structures. Despite significant progresses in the area of experimental protein structure determination, the sequence-structure gap is continually widening. Data driven homology based computational methods have proved successful in predicting tertiary structures for sequences sharing medium to high sequence similarities. With dwindling similarities of query sequences, advanced homology/ ab initio hybrid approaches are being explored to solve structure prediction problem. Here we describe Bhageerath-H, a homology/ ab initio hybrid software/server for predicting protein tertiary structures with advancing drug design attempts as one of the goals. Results Bhageerath-H web-server was validated on 75 CASP10 targets which showed TM-scores ≥0.5 in 91% of the cases and Cα RMSDs ≤5Å from the native in 58% of the targets, which is well above the CASP10 water mark. Comparison with some leading servers demonstrated the uniqueness of the hybrid methodology in effectively sampling conformational space, scoring best decoys and refining low resolution models to high and medium resolution. Conclusion Bhageerath-H methodology is web enabled for the scientific community as a freely accessible web server. The methodology is fielded in the on-going CASP11 experiment. PMID:25521245

Primary structure and functional characterization of a Drosophila dopamine receptor with high homology to human D1/5 receptors.

PubMed

Gotzes, F; Balfanz, S; Baumann, A

1994-01-01

Members of the superfamily of G-protein coupled receptors share significant similarities in sequence and transmembrane architecture. We have isolated a Drosophila homologue of the mammalian dopamine receptor family using a low stringency hybridization approach. The deduced amino acid sequence is approximately 70% homologous to the human D1/D5 receptors. When expressed in HEK 293 cells, the Drosophila receptor stimulates cAMP production in response to dopamine application. This effect was mimicked by SKF 38393, a specific D1 receptor agonist, but inhibited by dopaminergic antagonists such as butaclamol and flupentixol. In situ hybridization revealed that the Drosophila dopamine receptor is highly expressed in the somata of the optic lobes. This suggests that the receptor might be involved in the processing of visual information and/or visual learning in invertebrates.

Cloning and expression of Bartonella henselae sucB gene encoding an immunogenic dihydrolipoamide succinyltransferase homologous protein.

PubMed

Kabeya, Hidenori; Maruyama, Soichi; Hirano, Kouji; Mikami, Takeshi

2003-01-01

Immunoscreening of a ZAP genomic library of Bartonella henselae strain Houston-1 expressed in Escherichia coli resulted in the isolation of a clone containing 3.5 kb BamHI genomic DNA fragment. This 3.5 kb DNA fragment was found to contain a sequence of a gene encoding a protein with significant homology to the dihydrolipoamide succinyltransferase of Brucella melitensis (sucB). Subsequent cloning and DNA sequence analysis revealed that the deduced amino acid sequence from the cloned gene showed 66.5% identity to SucB protein of B. melitensis, and 43.4 and 47.2% identities to those of Coxiella burnetii and E. coli, respectively. The gene was expressed as a His-Nus A-tagged fusion protein. The recombinant SucB protein (rSucB) was shown to be an immunoreactive protein of about 115 kDa by Western blot analysis with sera from B. henselae-immunized mice. Therefore the rSucB may be a candidate antigen for a specific serological diagnosis of B. henselae infection.

Evolutionary profiles from the QR factorization of multiple sequence alignments

PubMed Central

Sethi, Anurag; O'Donoghue, Patrick; Luthey-Schulten, Zaida

2005-01-01

We present an algorithm to generate complete evolutionary profiles that represent the topology of the molecular phylogenetic tree of the homologous group. The method, based on the multidimensional QR factorization of numerically encoded multiple sequence alignments, removes redundancy from the alignments and orders the protein sequences by increasing linear dependence, resulting in the identification of a minimal basis set of sequences that spans the evolutionary space of the homologous group of proteins. We observe a general trend that these smaller, more evolutionarily balanced profiles have comparable and, in many cases, better performance in database searches than conventional profiles containing hundreds of sequences, constructed in an iterative and computationally intensive procedure. For more diverse families or superfamilies, with sequence identity <30%, structural alignments, based purely on the geometry of the protein structures, provide better alignments than pure sequence-based methods. Merging the structure and sequence information allows the construction of accurate profiles for distantly related groups. These structure-based profiles outperformed other sequence-based methods for finding distant homologs and were used to identify a putative class II cysteinyl-tRNA synthetase (CysRS) in several archaea that eluded previous annotation studies. Phylogenetic analysis showed the putative class II CysRSs to be a monophyletic group and homology modeling revealed a constellation of active site residues similar to that in the known class I CysRS. PMID:15741270

Metagenomic ventures into outer sequence space.

PubMed

Dutilh, Bas E

Sequencing DNA or RNA directly from the environment often results in many sequencing reads that have no homologs in the database. These are referred to as "unknowns," and reflect the vast unexplored microbial sequence space of our biosphere, also known as "biological dark matter." However, unknowns also exist because metagenomic datasets are not optimally mined. There is a pressure on researchers to publish and move on, and the unknown sequences are often left for what they are, and conclusions drawn based on reads with annotated homologs. This can cause abundant and widespread genomes to be overlooked, such as the recently discovered human gut bacteriophage crAssphage. The unknowns may be enriched for bacteriophage sequences, the most abundant and genetically diverse component of the biosphere and of sequence space. However, it remains an open question, what is the actual size of biological sequence space? The de novo assembly of shotgun metagenomes is the most powerful tool to address this question.

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase.

PubMed Central

Haggarty, N W; Dunbar, B; Fothergill, L A

1983-01-01

The complete amino acid sequence of human erythrocyte diphosphoglycerate mutase, comprising 239 residues, was determined. The sequence was deduced from the four cyanogen bromide fragments, and from the peptides derived from these fragments after digestion with a number of proteolytic enzymes. Comparison of this sequence with that of the yeast glycolytic enzyme, phosphoglycerate mutase, shows that these enzymes are 47% identical. Most, but not all, of the residues implicated as being important for the activity of the glycolytic mutase are conserved in the erythrocyte diphosphoglycerate mutase. PMID:6313356

Tocopherol and tocotrienol homologs in parenteral lipid emulsions

PubMed Central

Xu, Zhidong; Harvey, Kevin A; Pavlina, Thomas M; Zaloga, Gary P; Siddiqui, Rafat A

2015-01-01

Parenteral lipid emulsions, which are made of oils from plant and fish sources, contain different types of tocopherols and tocotrienols (vitamin E homologs). The amount and types of vitamin E homologs in various lipid emulsions vary considerably and are not completely known. The objective of this analysis was to develop a quantitative method to determine levels of all vitamin E homologs in various lipid emulsions. An HPLC system was used to measure vitamin E homologs using a Pinnacle DB Silica normal phase column and an isocratic, n-hexane:1,4 dioxane (98:2) mobile phase. An optimized protocol was used to report vitamin E homolog concentrations in soybean oil-based (Intralipid®, Ivelip®, Lipofundin® N, Liposyn® III, and Liposyn® II), medium- and long-chain fatty acid-based (Lipofundin®, MCT and Structolipid®), olive oil-based (ClinOleic®), and fish oil-based (Omegaven®) and mixture of these oils-based (SMOFlipid®, Lipidem®) commercial parenteral lipid emulsions. Total content of all vitamin E homologs varied greatly between different emulsions, ranging from 57.9 to 383.9 µg/mL. Tocopherols (α, β, γ, δ) were the predominant vitamin E homologs for all emulsions, with tocotrienol content < 0.3%. In all of the soybean emulsions, except for Lipofundin® N, the predominant vitamin E homolog was γ-tocopherol, which ranged from 57–156 µg/mL. ClinOleic® predominantly contained α-tocopherol (32 µg/mL), whereas α-tocopherol content in Omegaven® was higher than most of the other lipid emulsions (230 µg/mL). Practical applications The information on the types and quantity of vitamin E homologs in various lipid emulsions will be extremely useful to physicians and healthcare personnel in selecting appropriate lipid emulsions that are exclusively used in patients with inadequate gastrointestinal function, including hospitalized and critically ill patients. Some emulsions may require vitamin E supplementation in order to meet minimal human requirements

DETERMINATE and LATE FLOWERING are two TERMINAL FLOWER1/CENTRORADIALIS homologs that control two distinct phases of flowering initiation and development in pea.

PubMed

Foucher, Fabrice; Morin, Julie; Courtiade, Juliette; Cadioux, Sandrine; Ellis, Noel; Banfield, Mark J; Rameau, Catherine

2003-11-01

Genes in the TERMINAL FLOWER1 (TFL1)/CENTRORADIALIS family are important key regulatory genes involved in the control of flowering time and floral architecture in several different plant species. To understand the functions of TFL1 homologs in pea, we isolated three TFL1 homologs, which we have designated PsTFL1a, PsTFL1b, and PsTFL1c. By genetic mapping and sequencing of mutant alleles, we demonstrate that PsTFL1a corresponds to the DETERMINATE (DET) gene and PsTFL1c corresponds to the LATE FLOWERING (LF) gene. DET acts to maintain the indeterminacy of the apical meristem during flowering, and consistent with this role, DET expression is limited to the shoot apex after floral initiation. LF delays the induction of flowering by lengthening the vegetative phase, and allelic variation at the LF locus is an important component of natural variation for flowering time in pea. The most severe class of alleles flowers early and carries either a deletion of the entire PsTFL1c gene or an amino acid substitution. Other natural and induced alleles for LF, with an intermediate flowering time phenotype, present no changes in the PsTFL1c amino acid sequence but affect LF transcript level in the shoot apex: low LF transcript levels are correlated with early flowering, and high LF transcript levels are correlated with late flowering. Thus, different TFL1 homologs control two distinct aspects of plant development in pea, whereas a single gene, TFL1, performs both functions in Arabidopsis. These results show that different species have evolved different strategies to control key developmental transitions and also that the genetic basis for natural variation in flowering time may differ among plant species.

Analysis of eight out genes in a cluster required for pectic enzyme secretion by Erwinia chrysanthemi: sequence comparison with secretion genes from other gram-negative bacteria.

PubMed Central

Lindeberg, M; Collmer, A

1992-01-01

Many extracellular proteins produced by Erwinia chrysanthemi require the out gene products for transport across the outer membrane. In a previous report (S. Y. He, M. Lindeberg, A. K. Chatterjee, and A. Collmer, Proc. Natl. Acad. Sci. USA 88:1079-1083, 1991) cosmid pCPP2006, sufficient for secretion of Erwinia chrysanthemi extracellular proteins by Escherichia coli, was partially sequenced, revealing four out genes sharing high homology with pulH through pulK from Klebsiella oxytoca. The nucleotide sequence of eight additional out genes reveals homology with pulC through pulG, pulL, pulM, pulO, and other genes involved in secretion by various gram-negative bacteria. Although signal sequences and hydrophobic regions are generally conserved between Pul and Out proteins, four out genes contain unique inserts, a pulN homolog is not present, and outO appears to be transcribed separately from outC through outM. The sequenced region was subcloned, and an additional 7.6-kb region upstream was identified as being required for secretion in E. coli. out gene homologs were found on Erwinia carotovora cosmid clone pAKC651 but were not detected in E. coli. The outC-through-outM operon is weakly induced by polygalacturonic acid and strongly expressed in the early stationary phase. The out and pul genes are highly similar in sequence, hydropathic properties, and overall arrangement but differ in both transcriptional organization and the nature of their induction. Images PMID:1429461

Biological activity of cannabichromene, its homologs and isomers.

PubMed

Turner, C E; Elsohly, M A

1981-01-01

Cannabichromene (CBC) is one of four major cannabinoids in Cannabis sativa L. and is the second most abundant cannabinoid in drug-type cannabis. Cannabichromene and some of its homologs, analogs, and isomers were evaluated for antiinflammatory, antibacterial, and antifungal activity. Antiinflammatory activity was evaluated by the carrageenan-induced rat paw edema and the erythrocyte membrane stabilization method. In both tests, CBC was superior to phenylbutazone. Antibacterial activity of CBC and its isomers and homologs was evaluated using gram-positive, gram-negative, and acid-fast bacteria. Antifungal activity was evaluated using yeast-like and filamentous fungi and a dermatophyte. Antibacterial activity was strong, and the antifungal activity was mild to moderate.

Divergence and evolution of homologous regions of Bombyx mori nuclear polyhedrosis virus.

PubMed Central

Majima, K; Kobara, R; Maeda, S

1993-01-01

Homologous regions (hrs) (hr1,hr2-left,hr2-right,hr3,hr4-left,hr 4-right, and hr5) similar to those found in the Autographa californica nuclear polyhedrosis virus (AcNPV) genome were found in the Bombyx mori NPV (BmNPV) genome. The BmNPV hrs contained two to eight repeats of a homologous nucleotide sequence which were on average about 75 bp long. All of these homologous sequence repeats contained a 26-bp-long palindrome motif with an EcoRI or EcoRI-like site at its core. The consensus sequence of the BmNPV hrs showed 95% conservation with respect to those found in AcNPV. Nucleotide sequence analysis indicated that hr2-left and hr2-right of BmNPV evolved from an ancestor similar to hr2 of AcNPV by inversion, cleavage, and ligation. The polarities of the BmNPV and AcNPV hrs were conserved except for that of hr4-left. Within hr4-right of BmNPV, four repeats of a previously underscribed palindrome motif were found. Bmhr5D, a BmNPV mutant which lacked hr5, replicated at a rate similar to that of wild-type BmNPV in BmN cells and silkworm larvae, indicating that hr5 was not essential for viral replication. After ten passages of Bmhr5D in BmN cells, no detectable changes in its genome were observed by restriction endonuclease analysis. The evolution and divergence of the BmNPV genome are also discussed. Images PMID:8230471

Quantum-Sequencing: Biophysics of quantum tunneling through nucleic acids

NASA Astrophysics Data System (ADS)

Casamada Ribot, Josep; Chatterjee, Anushree; Nagpal, Prashant

2014-03-01

Tunneling microscopy and spectroscopy has extensively been used in physical surface sciences to study quantum tunneling to measure electronic local density of states of nanomaterials and to characterize adsorbed species. Quantum-Sequencing (Q-Seq) is a new method based on tunneling microscopy for electronic sequencing of single molecule of nucleic acids. A major goal of third-generation sequencing technologies is to develop a fast, reliable, enzyme-free single-molecule sequencing method. Here, we present the unique ``electronic fingerprints'' for all nucleotides on DNA and RNA using Q-Seq along their intrinsic biophysical parameters. We have analyzed tunneling spectra for the nucleotides at different pH conditions and analyzed the HOMO, LUMO and energy gap for all of them. In addition we show a number of biophysical parameters to further characterize all nucleobases (electron and hole transition voltage and energy barriers). These results highlight the robustness of Q-Seq as a technique for next-generation sequencing.

Searching remote homology with spectral clustering with symmetry in neighborhood cluster kernels.

PubMed

Maulik, Ujjwal; Sarkar, Anasua

2013-01-01

Remote homology detection among proteins utilizing only the unlabelled sequences is a central problem in comparative genomics. The existing cluster kernel methods based on neighborhoods and profiles and the Markov clustering algorithms are currently the most popular methods for protein family recognition. The deviation from random walks with inflation or dependency on hard threshold in similarity measure in those methods requires an enhancement for homology detection among multi-domain proteins. We propose to combine spectral clustering with neighborhood kernels in Markov similarity for enhancing sensitivity in detecting homology independent of "recent" paralogs. The spectral clustering approach with new combined local alignment kernels more effectively exploits the unsupervised protein sequences globally reducing inter-cluster walks. When combined with the corrections based on modified symmetry based proximity norm deemphasizing outliers, the technique proposed in this article outperforms other state-of-the-art cluster kernels among all twelve implemented kernels. The comparison with the state-of-the-art string and mismatch kernels also show the superior performance scores provided by the proposed kernels. Similar performance improvement also is found over an existing large dataset. Therefore the proposed spectral clustering framework over combined local alignment kernels with modified symmetry based correction achieves superior performance for unsupervised remote homolog detection even in multi-domain and promiscuous domain proteins from Genolevures database families with better biological relevance. Source code available upon request. sarkar@labri.fr.

Amino acid sequence of the Amur tiger prion protein.

PubMed

Wu, Changde; Pang, Wanyong; Zhao, Deming

2006-10-01

Prion diseases are fatal neurodegenerative disorders in human and animal associated with conformational conversion of a cellular prion protein (PrP(C)) into the pathologic isoform (PrP(Sc)). Various data indicate that the polymorphisms within the open reading frame (ORF) of PrP are associated with the susceptibility and control the species barrier in prion diseases. In the present study, partial Prnp from 25 Amur tigers (tPrnp) were cloned and screened for polymorphisms. Four single nucleotide polymorphisms (T423C, A501G, C511A, A610G) were found; the C511A and A610G nucleotide substitutions resulted in the amino acid changes Lysine171Glutamine and Alanine204Threoine, respectively. The tPrnp amino acid sequence is similar to house cat (Felis catus ) and sheep, but differs significantly from other two cat Prnp sequences that were previously deposited in GenBank.

Thermal adaptation analyzed by comparison of protein sequences from mesophilic and extremely thermophilic Methanococcus species

NASA Technical Reports Server (NTRS)

Haney, P. J.; Badger, J. H.; Buldak, G. L.; Reich, C. I.; Woese, C. R.; Olsen, G. J.

1999-01-01

The genome sequence of the extremely thermophilic archaeon Methanococcus jannaschii provides a wealth of data on proteins from a thermophile. In this paper, sequences of 115 proteins from M. jannaschii are compared with their homologs from mesophilic Methanococcus species. Although the growth temperatures of the mesophiles are about 50 degrees C below that of M. jannaschii, their genomic G+C contents are nearly identical. The properties most correlated with the proteins of the thermophile include higher residue volume, higher residue hydrophobicity, more charged amino acids (especially Glu, Arg, and Lys), and fewer uncharged polar residues (Ser, Thr, Asn, and Gln). These are recurring themes, with all trends applying to 83-92% of the proteins for which complete sequences were available. Nearly all of the amino acid replacements most significantly correlated with the temperature change are the same relatively conservative changes observed in all proteins, but in the case of the mesophile/thermophile comparison there is a directional bias. We identify 26 specific pairs of amino acids with a statistically significant (P < 0.01) preferred direction of replacement.

Non-homologous isofunctional enzymes: a systematic analysis of alternative solutions in enzyme evolution.

PubMed

Omelchenko, Marina V; Galperin, Michael Y; Wolf, Yuri I; Koonin, Eugene V

2010-04-30

Evolutionarily unrelated proteins that catalyze the same biochemical reactions are often referred to as analogous - as opposed to homologous - enzymes. The existence of numerous alternative, non-homologous enzyme isoforms presents an interesting evolutionary problem; it also complicates genome-based reconstruction of the metabolic pathways in a variety of organisms. In 1998, a systematic search for analogous enzymes resulted in the identification of 105 Enzyme Commission (EC) numbers that included two or more proteins without detectable sequence similarity to each other, including 34 EC nodes where proteins were known (or predicted) to have distinct structural folds, indicating independent evolutionary origins. In the past 12 years, many putative non-homologous isofunctional enzymes were identified in newly sequenced genomes. In addition, efforts in structural genomics resulted in a vastly improved structural coverage of proteomes, providing for definitive assessment of (non)homologous relationships between proteins. We report the results of a comprehensive search for non-homologous isofunctional enzymes (NISE) that yielded 185 EC nodes with two or more experimentally characterized - or predicted - structurally unrelated proteins. Of these NISE sets, only 74 were from the original 1998 list. Structural assignments of the NISE show over-representation of proteins with the TIM barrel fold and the nucleotide-binding Rossmann fold. From the functional perspective, the set of NISE is enriched in hydrolases, particularly carbohydrate hydrolases, and in enzymes involved in defense against oxidative stress. These results indicate that at least some of the non-homologous isofunctional enzymes were recruited relatively recently from enzyme families that are active against related substrates and are sufficiently flexible to accommodate changes in substrate specificity.

Partial characterization of the lettuce infectious yellows virus genomic RNAs, identification of the coat protein gene and comparison of its amino acid sequence with those of other filamentous RNA plant viruses.

PubMed

Klaassen, V A; Boeshore, M; Dolja, V V; Falk, B W

1994-07-01

Purified virions of lettuce infectious yellows virus (LIYV), a tentative member of the closterovirus group, contained two RNAs of approximately 8500 and 7300 nucleotides (RNAs 1 and 2 respectively) and a single coat protein species with M(r) of approximately 28,000. LIYV-infected plants contained multiple dsRNAs. The two largest were the correct size for the replicative forms of LIYV virion RNAs 1 and 2. To assess the relationships between LIYV RNAs 1 and 2, cDNAs corresponding to the virion RNAs were cloned. Northern blot hybridization analysis showed no detectable sequence homology between these RNAs. A partial amino acid sequence obtained from purified LIYV coat protein was found to align in the most upstream of four complete open reading frames (ORFs) identified in a LIYV RNA 2 cDNA clone. The identity of this ORF was confirmed as the LIYV coat protein gene by immunological analysis of the gene product expressed in vitro and in Escherichia coli. Computer analysis of the LIYV coat protein amino acid sequence indicated that it belongs to a large family of proteins forming filamentous capsids of RNA plant viruses. The LIYV coat protein appears to be most closely related to the coat proteins of two closteroviruses, beet yellows virus and citrus tristeza virus.

[Cloning and bioinformatics analysis of abscisic acid 8'-hydroxylase from Pseudostellariae Radix].

PubMed

Li, Jun; Long, Deng-Kai; Zhou, Tao; Ding, Ling; Zheng, Wei; Jiang, Wei-Ke

2016-07-01

Abscisic acid 8'-hydroxylase was one of key enzymes genes in the metabolism of abscisic acid (ABA). Seven menbers of abscisic acid 8'-hydroxylase were identified from Pseudostellaria heterophylla transcriptome sequencing results by using sequence homology. The expression profiles of these genes were analyzed by transcriptome data. The coding sequence of ABA8ox1 was cloned and analyzed by informational technology. The full-length cDNA of ABA8ox1 was 1 401 bp,with 480 encoded amino acids. The predicated isoelectric point (pI) and relative molecular mass (MW) were 8.55 and 53 kDa,respectively. Transmembrane structure analysis showed that there were 21 amino acids in-side and 445 amino acids out-side. High level of transcripts can detect in bark of root and fibrous root. Multi-alignment and phylogenetic analysis both show that ABA8ox1 had a high similarity with the CYP707As from other plants,especially with AtCYP707A1 and AtCYP707A3 in Arabidopsis thaliana. These results lay a foundation for molecular mechanism of tuberous root expanding and response to adversity stress. Copyright© by the Chinese Pharmaceutical Association.

Gene Discovery through Genomic Sequencing of Brucella abortus

PubMed Central

Sánchez, Daniel O.; Zandomeni, Ruben O.; Cravero, Silvio; Verdún, Ramiro E.; Pierrou, Ester; Faccio, Paula; Diaz, Gabriela; Lanzavecchia, Silvia; Agüero, Fernán; Frasch, Alberto C. C.; Andersson, Siv G. E.; Rossetti, Osvaldo L.; Grau, Oscar; Ugalde, Rodolfo A.

2001-01-01

Brucella abortus is the etiological agent of brucellosis, a disease that affects bovines and human. We generated DNA random sequences from the genome of B. abortus strain 2308 in order to characterize molecular targets that might be useful for developing immunological or chemotherapeutic strategies against this pathogen. The partial sequencing of 1,899 clones allowed the identification of 1,199 genomic sequence surveys (GSSs) with high homology (BLAST expect value < 10−5) to sequences deposited in the GenBank databases. Among them, 925 represent putative novel genes for the Brucella genus. Out of 925 nonredundant GSSs, 470 were classified in 15 categories based on cellular function. Seven hundred GSSs showed no significant database matches and remain available for further studies in order to identify their function. A high number of GSSs with homology to Agrobacterium tumefaciens and Rhizobium meliloti proteins were observed, thus confirming their close phylogenetic relationship. Among them, several GSSs showed high similarity with genes related to nodule nitrogen fixation, synthesis of nod factors, nodulation protein symbiotic plasmid, and nodule bacteroid differentiation. We have also identified several B. abortus homologs of virulence and pathogenesis genes from other pathogens, including a homolog to both the Shda gene from Salmonella enterica serovar Typhimurium and the AidA-1 gene from Escherichia coli. Other GSSs displayed significant homologies to genes encoding components of the type III and type IV secretion machineries, suggesting that Brucella might also have an active type III secretion machinery. PMID:11159979

Isolation and characterization of an AGAMOUS homolog from Fraxinus pennsylvanica

Treesearch

Ningxia Du; Paula M. Pijut

2010-01-01

An AGAMOUS homolog (FpAG) was isolated from green ash (Fraxinus pennsylvanica) using a reverse transcriptase polymerase chain reaction method. Southern blot analysis indicated that FpAG was present as a single-copy sequence in the genome of green ash. RNA accumulated in the reproductive tissues (female...

Method for high-volume sequencing of nucleic acids: random and directed priming with libraries of oligonucleotides

DOEpatents

Studier, F. William

1995-04-18

Random and directed priming methods for determining nucleotide sequences by enzymatic sequencing techniques, using libraries of primers of lengths 8, 9 or 10 bases, are disclosed. These methods permit direct sequencing of nucleic acids as large as 45,000 base pairs or larger without the necessity for subcloning. Individual primers are used repeatedly to prime sequence reactions in many different nucleic acid molecules. Libraries containing as few as 10,000 octamers, 14,200 nonamers, or 44,000 decamers would have the capacity to determine the sequence of almost any cosmid DNA. Random priming with a fixed set of primers from a smaller library can also be used to initiate the sequencing of individual nucleic acid molecules, with the sequence being completed by directed priming with primers from the library. In contrast to random cloning techniques, a combined random and directed priming strategy is far more efficient.

Method for high-volume sequencing of nucleic acids: random and directed priming with libraries of oligonucleotides

DOEpatents

Studier, F.W.

1995-04-18

Random and directed priming methods for determining nucleotide sequences by enzymatic sequencing techniques, using libraries of primers of lengths 8, 9 or 10 bases, are disclosed. These methods permit direct sequencing of nucleic acids as large as 45,000 base pairs or larger without the necessity for subcloning. Individual primers are used repeatedly to prime sequence reactions in many different nucleic acid molecules. Libraries containing as few as 10,000 octamers, 14,200 nonamers, or 44,000 decamers would have the capacity to determine the sequence of almost any cosmid DNA. Random priming with a fixed set of primers from a smaller library can also be used to initiate the sequencing of individual nucleic acid molecules, with the sequence being completed by directed priming with primers from the library. In contrast to random cloning techniques, a combined random and directed priming strategy is far more efficient. 2 figs.

Asymmetric synthesis of α-amino acids via homologation of Ni(II) complexes of glycine Schiff bases. Part 2: aldol, Mannich addition reactions, deracemization and (S) to (R) interconversion of α-amino acids.

PubMed

Sorochinsky, Alexander E; Aceña, José Luis; Moriwaki, Hiroki; Sato, Tatsunori; Soloshonok, Vadim

2013-11-01

This review provides a comprehensive treatment of literature data dealing with asymmetric synthesis of α-amino-β-hydroxy and α,β-diamino acids via homologation of chiral Ni(II) complexes of glycine Schiff bases using aldol and Mannich-type reactions. These reactions proceed with synthetically useful chemical yields and thermodynamically controlled stereoselectivity and allow direct introduction of two stereogenic centers in a single operation with predictable stereochemical outcome. Furthermore, new application of Ni(II) complexes of α-amino acids Schiff bases for deracemization of racemic α-amino acids and (S) to (R) interconversion providing additional synthetic opportunities for preparation of enantiomerically pure α-amino acids, is also reviewed. Origin of observed diastereo-/enantioselectivity in the aldol, Mannich-type and deracemization reactions, generality and limitations of these methodologies are critically discussed.

Description of durancin TW-49M, a novel enterocin B-homologous bacteriocin in carrot-isolated Enterococcus durans QU 49.

PubMed

Hu, C-B; Zendo, T; Nakayama, J; Sonomoto, K

2008-09-01

To characterize the novel bacteriocin produced by Enterococcus durans. Enterococcus durans QU 49 was isolated from carrot and expressed bactericidal activity over 20-43 degrees C. Bacteriocins were purified to homogeneity using the three-step purification method, one of which, termed durancin TW-49M, was an enterocin B-homologous peptide with most identical residues occurring in the N-terminus. Durancin TW-49M was more tolerant in acidic than in alkali. DNA sequencing analysis revealed durancin TW-49M was translated as a prepeptide of the double-glycine type. Durancin TW-49M and enterocin B expressed similar antimicrobial spectra, in which no significant variation due to the diversity in their C-termini was observed. Durancin TW-49M, a novel nonpediocin-like class II bacteriocin, was characterized to the amino acid and genetic levels. The diverse C-terminal parts of durancin TW-49M and enterocin B were hardly to be suggested as the place determining the target cell specificity. This is the first and comprehensive study of a novel bacteriocin produced by Ent. durans. The high homology at the N-terminal halves between durancin TW-49M and enterocin B makes them suitable to study the structure-function relationship of bacteriocins and their immunity proteins.

Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

NASA Technical Reports Server (NTRS)

Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

1992-01-01

Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

Conservation of Shannon's redundancy for proteins. [information theory applied to amino acid sequences

NASA Technical Reports Server (NTRS)

Gatlin, L. L.

1974-01-01

Concepts of information theory are applied to examine various proteins in terms of their redundancy in natural originators such as animals and plants. The Monte Carlo method is used to derive information parameters for random protein sequences. Real protein sequence parameters are compared with the standard parameters of protein sequences having a specific length. The tendency of a chain to contain some amino acids more frequently than others and the tendency of a chain to contain certain amino acid pairs more frequently than other pairs are used as randomness measures of individual protein sequences. Non-periodic proteins are generally found to have random Shannon redundancies except in cases of constraints due to short chain length and genetic codes. Redundant characteristics of highly periodic proteins are discussed. A degree of periodicity parameter is derived.

Recombination–deletion between homologous cassettes in retrovirus is suppressed via a strategy of degenerate codon substitution

PubMed Central

Im, Eung Jun; Bais, Anthony J; Yang, Wen; Ma, Qiangzhong; Guo, Xiuyang; Sepe, Steven M; Junghans, Richard P

2014-01-01

Transduction and expression procedures in gene therapy protocols may optimally transfer more than a single gene to correct a defect and/or transmit new functions to recipient cells or organisms. This may be accomplished by transduction with two (or more) vectors, or, more efficiently, in a single vector. Occasionally, it may be useful to coexpress homologous genes or chimeric proteins with regions of shared homology. Retroviridae include the dominant vector systems for gene transfer (e.g., gamma-retro and lentiviruses) and are capable of such multigene expression. However, these same viruses are known for efficient recombination–deletion when domains are duplicated within the viral genome. This problem can be averted by resorting to two-vector strategies (two-chain two-vector), but at a penalty to cost, convenience, and efficiency. Employing a chimeric antigen receptor system as an example, we confirm that coexpression of two genes with homologous domains in a single gamma-retroviral vector (two-chain single-vector) leads to recombination–deletion between repeated sequences, excising the equivalent of one of the chimeric antigen receptors. Here, we show that a degenerate codon substitution strategy in the two-chain single-vector format efficiently suppressed intravector deletional loss with rescue of balanced gene coexpression by minimizing sequence homology between repeated domains and preserving the final protein sequence. PMID:25419532

Isolation of complementary DNA clones encoding pathogenesis-related proteins P and Q, two acidic chitinases from tobacco.

PubMed Central

Payne, G; Ahl, P; Moyer, M; Harper, A; Beck, J; Meins, F; Ryals, J

1990-01-01

Complementary DNA clones encoding two isoforms of the acidic endochitinase (chitinase, EC 3.2.1.14) from tobacco were isolated. Comparison of amino acid sequences deduced from the cDNA clones and the sequence of peptides derived from purified proteins show that these clones encode the pathogenesis-related proteins PR-P and PR-Q. The cDNA inserts were not homologous to either the bacterial form of chitinase or the form from cucumber but shared significant homology to the basic form of chitinase from tobacco and bean. The acidic isoforms of tobacco chitinase did not contain the amino-terminal, cysteine-rich "hevein" domain found in the basic isoforms, indicating that this domain, which binds chitin, is not essential for chitinolytic activity. The accumulation of mRNA for the pathogenesis-related proteins PR-1, PR-R, PR-P, and PR-Q in Xanthi.nc tobacco leaves following infection with tobacco mosaic virus was measured by primer extension. The results indicate that the induction of these proteins during the local necrotic lesion response to the virus is coordinated at the mRNA level. Images PMID:2296608

Analysis of the DNA sequence of a 15,500 bp fragment near the left telomere of chromosome XV from Saccharomyces cerevisiae reveals a putative sugar transporter, a carboxypeptidase homologue and two new open reading frames.

PubMed

Gamo, F J; Lafuente, M J; Casamayor, A; Ariño, J; Aldea, M; Casas, C; Herrero, E; Gancedo, C

1996-06-15

We report the sequence of a 15.5 kb DNA segment located near the left telomere of chromosome XV of Saccharomyces cerevisiae. The sequence contains nine open reading frames (ORFs) longer than 300 bp. Three of them are internal to other ones. One corresponds to the gene LGT3 that encodes a putative sugar transporter. Three adjacent ORFs were separated by two stop codons in frame. These ORFs presented homology with the gene CPS1 that encodes carboxypeptidase S. The stop codons were not found in the same sequence derived from another yeast strain. Two other ORFs without significant homology in databases were also found. One of them, O0420, is very rich in serine and threonine and presents a series of repeated or similar amino acid stretches along the sequence.

Homologous and heterologous recombination between adenovirus vector DNA and chromosomal DNA.

PubMed

Stephen, Sam Laurel; Sivanandam, Vijayshankar Ganesh; Kochanek, Stefan

2008-11-01

Adenovirus vector DNA is perceived to remain as episome following gene transfer. We quantitatively and qualitatively analysed recombination between high capacity adenoviral vector (HC-AdV) and chromosomal DNA following gene transfer in vitro. We studied homologous and heterologous recombination with a single HC-AdV carrying (i) a large genomic HPRT fragment with the HPRT CHICAGO mutation causing translational stop upon homologous recombination with the HPRT locus and (ii) a selection marker to allow for clonal selection in the event of heterologous recombination. We analysed the sequences at the junctions between vector and chromosomal DNA. In primary cells and in cell lines, the frequency of homologous recombination ranged from 2 x 10(-5) to 1.6 x 10(-6). Heterologous recombination occurred at rates between 5.5 x 10(-3) and 1.1 x 10(-4). HC-AdV DNA integrated via the termini mostly as intact molecules. Analysis of the junction sequences indicated vector integration in a relatively random manner without an obvious preference for particular chromosomal regions, but with a preference for integration into genes. Integration into protooncogenes or tumor suppressor genes was not observed. Patchy homologies between vector termini and chromosomal DNA were found at the site of integration. Although the majority of integrations had occurred without causing mutations in the chromosomal DNA, cases of nucleotide substitutions and insertions were observed. In several cases, deletions of even relative large chromosomal regions were likely. These results extend previous information on the integration patterns of adenovirus vector DNA and contribute to a risk-benefit assessment of adenovirus-mediated gene transfer.

Generation and Analysis of Expressed Sequence Tags from Olea europaea L.

PubMed Central

Ozdemir Ozgenturk, Nehir; Oruç, Fatma; Sezerman, Ugur; Kuçukural, Alper; Vural Korkut, Senay; Toksoz, Feriha; Un, Cemal

2010-01-01

Olive (Olea europaea L.) is an important source of edible oil which was originated in Near-East region. In this study, two cDNA libraries were constructed from young olive leaves and immature olive fruits for generation of ESTs to discover the novel genes and search the function of unknown genes of olive. The randomly selected 3840 colonies were sequenced for EST collection from both libraries. Readable 2228 sequences for olive leaf and 1506 sequences for olive fruit were assembled into 205 and 69 contigs, respectively, whereas 2478 were singletons. Putative functions of all 2752 differentially expressed unique sequences were designated by gene homology based on BLAST and annotated using BLAST2GO. While 1339 ESTs show no homology to the database, 2024 ESTs have homology (under 80%) with hypothetical proteins, putative proteins, expressed proteins, and unknown proteins in NCBI-GenBank. 635 EST's unique genes sequence have been identified by over 80% homology to known function in other species which were not previously described in Olea family. Only 3.1% of total EST's was shown similarity with olive database existing in NCBI. This generated EST's data and consensus sequences were submitted to NCBI as valuable source for functional genome studies of olive. PMID:21197085

Complete Amino Acid Sequence of a Copper/Zinc-Superoxide Dismutase from Ginger Rhizome.

PubMed

Nishiyama, Yuki; Fukamizo, Tamo; Yoneda, Kazunari; Araki, Tomohiro

2017-04-01

Superoxide dismutase (SOD) is an antioxidant enzyme protecting cells from oxidative stress. Ginger (Zingiber officinale) is known for its antioxidant properties, however, there are no data on SODs from ginger rhizomes. In this study, we purified SOD from the rhizome of Z. officinale (Zo-SOD) and determined its complete amino acid sequence using N terminal sequencing, amino acid analysis, and de novo sequencing by tandem mass spectrometry. Zo-SOD consists of 151 amino acids with two signature Cu/Zn-SOD motifs and has high similarity to other plant Cu/Zn-SODs. Multiple sequence alignment showed that Cu/Zn-binding residues and cysteines forming a disulfide bond, which are highly conserved in Cu/Zn-SODs, are also present in Zo-SOD. Phylogenetic analysis revealed that plant Cu/Zn-SODs clustered into distinct chloroplastic, cytoplasmic, and intermediate groups. Among them, only chloroplastic enzymes carried amino acid substitutions in the region functionally important for enzymatic activity, suggesting that chloroplastic SODs may have a function distinct from those of SODs localized in other subcellular compartments. The nucleotide sequence of the Zo-SOD coding region was obtained by reverse-translation, and the gene was synthesized, cloned, and expressed. The recombinant Zo-SOD demonstrated pH stability in the range of 5-10, which is similar to other reported Cu/Zn-SODs, and thermal stability in the range of 10-60 °C, which is higher than that for most plant Cu/Zn-SODs but lower compared to the enzyme from a Z. officinale relative Curcuma aromatica.

Protein location prediction using atomic composition and global features of the amino acid sequence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cherian, Betsy Sheena, E-mail: betsy.skb@gmail.com; Nair, Achuthsankar S.

2010-01-22

Subcellular location of protein is constructive information in determining its function, screening for drug candidates, vaccine design, annotation of gene products and in selecting relevant proteins for further studies. Computational prediction of subcellular localization deals with predicting the location of a protein from its amino acid sequence. For a computational localization prediction method to be more accurate, it should exploit all possible relevant biological features that contribute to the subcellular localization. In this work, we extracted the biological features from the full length protein sequence to incorporate more biological information. A new biological feature, distribution of atomic composition is effectivelymore » used with, multiple physiochemical properties, amino acid composition, three part amino acid composition, and sequence similarity for predicting the subcellular location of the protein. Support Vector Machines are designed for four modules and prediction is made by a weighted voting system. Our system makes prediction with an accuracy of 100, 82.47, 88.81 for self-consistency test, jackknife test and independent data test respectively. Our results provide evidence that the prediction based on the biological features derived from the full length amino acid sequence gives better accuracy than those derived from N-terminal alone. Considering the features as a distribution within the entire sequence will bring out underlying property distribution to a greater detail to enhance the prediction accuracy.« less

Microorganisms for producing organic acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pfleger, Brian Frederick; Begemann, Matthew Brett

Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

Microorganisms for producing organic acids

DOEpatents

Pfleger, Brian Frederick; Begemann, Matthew Brett

2014-09-30

Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

Searching Remote Homology with Spectral Clustering with Symmetry in Neighborhood Cluster Kernels

PubMed Central

Maulik, Ujjwal; Sarkar, Anasua

2013-01-01

Remote homology detection among proteins utilizing only the unlabelled sequences is a central problem in comparative genomics. The existing cluster kernel methods based on neighborhoods and profiles and the Markov clustering algorithms are currently the most popular methods for protein family recognition. The deviation from random walks with inflation or dependency on hard threshold in similarity measure in those methods requires an enhancement for homology detection among multi-domain proteins. We propose to combine spectral clustering with neighborhood kernels in Markov similarity for enhancing sensitivity in detecting homology independent of “recent” paralogs. The spectral clustering approach with new combined local alignment kernels more effectively exploits the unsupervised protein sequences globally reducing inter-cluster walks. When combined with the corrections based on modified symmetry based proximity norm deemphasizing outliers, the technique proposed in this article outperforms other state-of-the-art cluster kernels among all twelve implemented kernels. The comparison with the state-of-the-art string and mismatch kernels also show the superior performance scores provided by the proposed kernels. Similar performance improvement also is found over an existing large dataset. Therefore the proposed spectral clustering framework over combined local alignment kernels with modified symmetry based correction achieves superior performance for unsupervised remote homolog detection even in multi-domain and promiscuous domain proteins from Genolevures database families with better biological relevance. Source code available upon request. Contact: sarkar@labri.fr. PMID:23457439

Human retroviruses and AIDS 1996. A compilation and analysis of nucleic acid and amino acid sequences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, G.; Foley, B.; Korber, B.

1997-04-01

This compendium and the accompanying floppy diskettes are the result of an effort to compile and rapidly publish all relevant molecular data concerning the human immunodeficiency viruses (HIV) and related retroviruses. The scope of the compendium and database is best summarized by the five parts that it comprises: (1) Nuclear Acid Alignments and Sequences; (2) Amino Acid Alignments; (3) Analysis; (4) Related Sequences; and (5) Database Communications. Information within all the parts is updated throughout the year on the Web site, http://hiv-web.lanl.gov. While this publication could take the form of a review or sequence monograph, it is not so conceived.more » Instead, the literature from which the database is derived has simply been summarized and some elementary computational analyses have been performed upon the data. Interpretation and commentary have been avoided insofar as possible so that the reader can form his or her own judgments concerning the complex information. In addition to the general descriptions of the parts of the compendium, the user should read the individual introductions for each part.« less

All five host-range variants of Xanthomonas citri carry one pthA homolog with 17.5 repeats that determines pathogenicity on citrus, but none determine host-range variation.

PubMed

Al-Saadi, Abdulwahid; Reddy, Joseph D; Duan, Yong P; Brunings, Asha M; Yuan, Qiaoping; Gabriel, Dean W

2007-08-01

Citrus canker disease is caused by five groups of Xanthomonas citri strains that are distinguished primarily by host range: three from Asia (A, A*, and A(w)) and two that form a phylogenetically distinct clade and originated in South America (B and C). Every X. citri strain carries multiple DNA fragments that hybridize with pthA, which is essential for the pathogenicity of wide-host-range X. citri group A strain 3213. DNA fragments that hybridized with pthA were cloned from a representative strain from all five groups. Each strain carried one and only one pthA homolog that functionally complemented a knockout mutation of pthA in 3213. Every complementing homolog was of identical size to pthA and carried 17.5 nearly identical, direct tandem repeats, including three new genes from narrow-host-range groups C (pthC), A(w) (pthAW), and A* (pthA*). Every noncomplementing paralog was of a different size; one of these was sequenced from group A* (pthA*-2) and was found to have an intact promoter and full-length reading frame but with 15.5 repeats. None of the complementing homologs nor any of the noncomplementing paralogs conferred avirulence to 3213 on grapefruit or suppressed avirulence of a group A* strain on grapefruit. A knockout mutation of pthC in a group C strain resulted in loss of pathogenicity on lime, but the strain was unaffected in ability to elicit an HR on grapefruit. This pthC- mutant was fully complemented by pthA, pthB, or pthC. Analysis of the predicted amino-acid sequences of all functional pthA homologs and nonfunctional paralogs indicated that the specific sequence of the 17th repeat may be essential for pathogenicity of X. citri on citrus.

Diagnostics based on nucleic acid sequence variant profiling: PCR, hybridization, and NGS approaches.

PubMed

Khodakov, Dmitriy; Wang, Chunyan; Zhang, David Yu

2016-10-01

Nucleic acid sequence variations have been implicated in many diseases, and reliable detection and quantitation of DNA/RNA biomarkers can inform effective therapeutic action, enabling precision medicine. Nucleic acid analysis technologies being translated into the clinic can broadly be classified into hybridization, PCR, and sequencing, as well as their combinations. Here we review the molecular mechanisms of popular commercial assays, and their progress in translation into in vitro diagnostics. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

The complete nucleotide sequence of RNA 3 of a peach isolate of Prunus necrotic ringspot virus.

PubMed

Hammond, R W; Crosslin, J M

1995-04-01

The complete nucleotide sequence of RNA 3 of the PE-5 peach isolate of Prunus necrotic ringspot ilarvirus (PNRSV) was obtained from cloned cDNA. The RNA sequence is 1941 nucleotides and contains two open reading frames (ORFs). ORF 1 consisted of 284 amino acids with a calculated molecular weight of 31,729 Da and ORF 2 contained 224 amino acids with a calculated molecular weight of 25,018 Da. ORF 2 corresponds to the coat protein gene. Expression of ORF 2 engineered into a pTrcHis vector in Escherichia coli results in a fusion polypeptide of approximately 28 kDa which cross-reacts with PNRSV polyclonal antiserum. Analysis of the coat protein amino acid sequence reveals a putative "zinc-finger" domain at the amino-terminal portion of the protein. Two tetranucleotide AUGC motifs occur in the 3'-UTR of the RNA and may function in coat protein binding and genome activation. ORF 1 homologies to other ilarviruses and alfalfa mosaic virus are confined to limited regions of conserved amino acids. The translated amino acid sequence of the coat protein gene shows 92% similarity to one isolate of apple mosaic virus, a closely related member of the ilarvirus group of plant viruses, but only 66% similarity to the amino acid sequence of the coat protein gene of a second isolate. These relationships are also reflected at the nucleotide sequence level. These results in one instance confirm the close similarities observed at the biophysical and serological levels between these two viruses, but on the other hand call into question the nomenclature used to describe these viruses.

A draft sequence of the rice genome (Oryza sativa L. ssp. indica).

PubMed

Yu, Jun; Hu, Songnian; Wang, Jun; Wong, Gane Ka-Shu; Li, Songgang; Liu, Bin; Deng, Yajun; Dai, Li; Zhou, Yan; Zhang, Xiuqing; Cao, Mengliang; Liu, Jing; Sun, Jiandong; Tang, Jiabin; Chen, Yanjiong; Huang, Xiaobing; Lin, Wei; Ye, Chen; Tong, Wei; Cong, Lijuan; Geng, Jianing; Han, Yujun; Li, Lin; Li, Wei; Hu, Guangqiang; Huang, Xiangang; Li, Wenjie; Li, Jian; Liu, Zhanwei; Li, Long; Liu, Jianping; Qi, Qiuhui; Liu, Jinsong; Li, Li; Li, Tao; Wang, Xuegang; Lu, Hong; Wu, Tingting; Zhu, Miao; Ni, Peixiang; Han, Hua; Dong, Wei; Ren, Xiaoyu; Feng, Xiaoli; Cui, Peng; Li, Xianran; Wang, Hao; Xu, Xin; Zhai, Wenxue; Xu, Zhao; Zhang, Jinsong; He, Sijie; Zhang, Jianguo; Xu, Jichen; Zhang, Kunlin; Zheng, Xianwu; Dong, Jianhai; Zeng, Wanyong; Tao, Lin; Ye, Jia; Tan, Jun; Ren, Xide; Chen, Xuewei; He, Jun; Liu, Daofeng; Tian, Wei; Tian, Chaoguang; Xia, Hongai; Bao, Qiyu; Li, Gang; Gao, Hui; Cao, Ting; Wang, Juan; Zhao, Wenming; Li, Ping; Chen, Wei; Wang, Xudong; Zhang, Yong; Hu, Jianfei; Wang, Jing; Liu, Song; Yang, Jian; Zhang, Guangyu; Xiong, Yuqing; Li, Zhijie; Mao, Long; Zhou, Chengshu; Zhu, Zhen; Chen, Runsheng; Hao, Bailin; Zheng, Weimou; Chen, Shouyi; Guo, Wei; Li, Guojie; Liu, Siqi; Tao, Ming; Wang, Jian; Zhu, Lihuang; Yuan, Longping; Yang, Huanming

2002-04-05

We have produced a draft sequence of the rice genome for the most widely cultivated subspecies in China, Oryza sativa L. ssp. indica, by whole-genome shotgun sequencing. The genome was 466 megabases in size, with an estimated 46,022 to 55,615 genes. Functional coverage in the assembled sequences was 92.0%. About 42.2% of the genome was in exact 20-nucleotide oligomer repeats, and most of the transposons were in the intergenic regions between genes. Although 80.6% of predicted Arabidopsis thaliana genes had a homolog in rice, only 49.4% of predicted rice genes had a homolog in A. thaliana. The large proportion of rice genes with no recognizable homologs is due to a gradient in the GC content of rice coding sequences.

"De-novo" amino acid sequence elucidation of protein G'e by combined "top-down" and "bottom-up" mass spectrometry.

PubMed

Yefremova, Yelena; Al-Majdoub, Mahmoud; Opuni, Kwabena F M; Koy, Cornelia; Cui, Weidong; Yan, Yuetian; Gross, Michael L; Glocker, Michael O

2015-03-01

Mass spectrometric de-novo sequencing was applied to review the amino acid sequence of a commercially available recombinant protein G´ with great scientific and economic importance. Substantial deviations to the published amino acid sequence (Uniprot Q54181) were found by the presence of 46 additional amino acids at the N-terminus, including a so-called "His-tag" as well as an N-terminal partial α-N-gluconoylation and α-N-phosphogluconoylation, respectively. The unexpected amino acid sequence of the commercial protein G' comprised 241 amino acids and resulted in a molecular mass of 25,998.9 ± 0.2 Da for the unmodified protein. Due to the higher mass that is caused by its extended amino acid sequence compared with the original protein G' (185 amino acids), we named this protein "protein G'e." By means of mass spectrometric peptide mapping, the suggested amino acid sequence, as well as the N-terminal partial α-N-gluconoylations, was confirmed with 100% sequence coverage. After the protein G'e sequence was determined, we were able to determine the expression vector pET-28b from Novagen with the Xho I restriction enzyme cleavage site as the best option that was used for cloning and expressing the recombinant protein G'e in E. coli. A dissociation constant (K(d)) value of 9.4 nM for protein G'e was determined thermophoretically, showing that the N-terminal flanking sequence extension did not cause significant changes in the binding affinity to immunoglobulins.

Resolution of model Holliday junctions by yeast endonuclease: effect of DNA structure and sequence.

PubMed Central

Parsons, C A; Murchie, A I; Lilley, D M; West, S C

1989-01-01

The resolution of Holliday junctions in DNA involves specific cleavage at or close to the site of the junction. A nuclease from Saccharomyces cerevisiae cleaves model Holliday junctions in vitro by the introduction of nicks in regions of duplex DNA adjacent to the crossover point. In previous studies [Parsons and West (1988) Cell, 52, 621-629] it was shown that cleavage occurred within homologous arm sequences with precise symmetry across the junction. In contrast, junctions with heterologous arm sequences were cleaved asymmetrically. In this work, we have studied the effect of sequence changes and base modification upon the site of cleavage. It is shown that the specificity of cleavage is unchanged providing that perfect homology is maintained between opposing arm sequences. However, in the absence of homology, cleavage depends upon sequence context and is affected by minor changes such as base modification. These data support the proposed mechanism for cleavage of a Holliday junction, which requires homologous alignment of arm sequences in an enzyme--DNA complex as a prerequisite for symmetrical cleavage by the yeast endonuclease. Images PMID:2653810

Correlation between fibroin amino acid sequence and physical silk properties.

PubMed

Fedic, Robert; Zurovec, Michal; Sehnal, Frantisek

2003-09-12

The fiber properties of lepidopteran silk depend on the amino acid repeats that interact during H-fibroin polymerization. The aim of our research was to relate repeat composition to insect biology and fiber strength. Representative regions of the H-fibroin genes were sequenced and analyzed in three pyralid species: wax moth (Galleria mellonella), European flour moth (Ephestia kuehniella), and Indian meal moth (Plodia interpunctella). The amino acid repeats are species-specific, evidently a diversification of an ancestral region of 43 residues, and include three types of regularly dispersed motifs: modifications of GSSAASAA sequence, stretches of tripeptides GXZ where X and Z represent bulky residues, and sequences similar to PVIVIEE. No concatenations of GX dipeptide or alanine, which are typical for Bombyx silkworms and Antheraea silk moths, respectively, were found. Despite different repeat structure, the silks of G. mellonella and E. kuehniella exhibit similar tensile strength as the Bombyx and Antheraea silks. We suggest that in these latter two species, variations in the repeat length obstruct repeat alignment, but sufficiently long stretches of iterated residues get superposed to interact. In the pyralid H-fibroins, interactions of the widely separated and diverse motifs depend on the precision of repeat matching; silk is strong in G. mellonella and E. kuehniella, with 2-3 types of long homogeneous repeats, and nearly 10 times weaker in P. interpunctella, with seven types of shorter erratic repeats. The high proportion of large amino acids in the H-fibroin of pyralids has probably evolved in connection with the spinning habit of caterpillars that live in protective silk tubes and spin continuously, enlarging the tubes on one end and partly devouring the other one. The silk serves as a depot of energetically rich and essential amino acids that may be scarce in the diet.

Msh2 Blocks an Alternative Mechanism for Non-Homologous Tail Removal during Single-Strand Annealing in Saccharomyces cerevisiae

PubMed Central

Manthey, Glenn M.; Naik, Nilan; Bailis, Adam M.

2009-01-01

Chromosomal translocations are frequently observed in cells exposed to agents that cause DNA double-strand breaks (DSBs), such as ionizing radiation and chemotherapeutic drugs, and are often associated with tumors in mammals. Recently, translocation formation in the budding yeast, Saccharomyces cerevisiae, has been found to occur at high frequencies following the creation of multiple DSBs adjacent to repetitive sequences on non-homologous chromosomes. The genetic control of translocation formation and the chromosome complements of the clones that contain translocations suggest that translocation formation occurs by single-strand annealing (SSA). Among the factors important for translocation formation by SSA is the central mismatch repair (MMR) and homologous recombination (HR) factor, Msh2. Here we describe the effects of several msh2 missense mutations on translocation formation that suggest that Msh2 has separable functions in stabilizing annealed single strands, and removing non-homologous sequences from their ends. Additionally, interactions between the msh2 alleles and a null allele of RAD1, which encodes a subunit of a nuclease critical for the removal of non-homologous tails suggest that Msh2 blocks an alternative mechanism for removing these sequences. These results suggest that Msh2 plays multiple roles in the formation of chromosomal translocations following acute levels of DNA damage. PMID:19834615