Transfer RNA molecules translate the genetic code by recognizing cognate mRNA codons during protein synthesis. The anticodon wobble at position 34 and the nucleotide immediately 3' to the anticodon triplet at position 37 display a large diversity of modified nucleosides in the tRNAs of all organisms. We show that tRNA species translating 2-fold degenerate codons require a ...
PubMed
The post-transcriptional nucleoside modifications of tRNA's anticodon domain form the loop structure and dynamics required for effective and accurate recognition of synonymous codons. The N(6)-threonylcarbamoyladenosine modification at position 37 (t(6)A(37)), 3'-adjacent to the anticodon, of many tRNA species in ...
The T box mechanism is widely used in Gram-positive bacteria to regulate expression of aminoacyl-tRNA synthetase genes and genes involved in amino acid biosynthesis and uptake. Binding of a specific uncharged tRNA to a riboswitch element in the nascent transcript causes a structural change in the transcript that promotes expression of the downstream coding sequence. In most ...
PubMed Central
Transfer RNA molecules are involved in a variety of biological processes, implying complex recognition events with proteins and other RNAs. From a structural point of view, tRNAs constitute a reference system for studying RNA folding and architecture. A deeper understanding of their structural and functional properties will derive from our ability to model ...
Structural studies of ribosome complexes with bound tRNAs and release factors show considerable contacts between these factors and helix 69 (H69) of 23 S rRNA. Although biochemical and genetic studies have provided some general insights into the role of H69 in tRNA and RF selection, a detailed understanding of these contributions remains elusive. Here, we present a pre- ...
In many prokaryotes the biosynthesis of the amide aminoacyl-tRNAs, Gln-tRNAGln and Asn-tRNAAsn, proceeds by an indirect route in which mischarged Glu-tRNAGln or Asp-tRNAAsn is amidated to the correct aminoacyl-tRNA catalyzed by a tRNA-dependent amidotransferase (AdT). Two types of AdTs exist: bacteria, ...
tRNAs, like other RNAs, are subject to quality control steps during and after biosynthesis. We previously described a rapid tRNA degradation (RTD) pathway in which the 5'-3' exonucleases Rat1 and Xrn1 degrade mature tRNA(Val(AAC)) in yeast mutants lacking m(7)G and m(5)C, and mature tRNA(Ser(CGA)) in mutants lacking Um and ac(4)C. To understand how the RTD pathway selects ...
The 13 nucleotide Xenopus laevis tyrosine tRNA gene intervening sequence was into a human serine suppressor tRNA gene which lacked an intron, by site-directed mutagenesis. Analysis of the products of in vitro transcription in a HeLa cell extract indicates that the intervening sequence is accurately removed to generate a mature sized ...
Fast conformational changes of biological macromolecules such as RNA folding and DNA-protein interactions play a crucial role in their biological functions. Conformational changes are supposed to take place in the sub milliseconds to few seconds time range. The development of appropriate dynamic methods possessing both high space (one nucleotide) and time resolution is of important interest. Here, ...
NASA Astrophysics Data System (ADS)
Transfer RNA's role in decoding the genome is critical to the accuracy and efficiency of protein synthesis. Though modified nucleosides were identified in RNA 50 years ago, only recently has their importance to tRNA's ability to decode cognate and wobble codons become apparent. RNA modifications are ubiquitous. To date, some 100 different posttranslational modifications have ...
The posttranscriptional modification of RNA is a significant investment in genes, enzymes, substrates, and energy. Advances in molecular genetics and structural biology indicate strongly that modifications of tRNA's anticodon domain control gene expression. Modifications at the anticodon's wobble position are required for recognition of rarely used codons ...
While recognized that some wobble exists in the base pairing of the first base of the tRNA anticodon with the third of the codon, specific base modifications have evolved to select particular codons. This modified-wobble theory would be exemplified by a single codon recognition imposed on the anticodon by modification of the tRNA ...
The elongator (ELP) complex consisting of Elp1-6p has been indicated to play roles in multiple cellular processes. In yeast, the ELP complex has been shown to genetically interact with Uba4p/Urm1p and Kti11-13p for a function in tRNA modification. Through a Caenorhabditis elegans genetic suppressor screen and positional cloning, we discovered that loss-of-function mutations of ...
Two archaeal tRNA methyltransferases belonging to the SPOUT superfamily and displaying unexpected activities are identified. These enzymes are orthologous to the yeast Trm10p methyltransferase, which catalyses the formation of 1-methylguanosine at position 9 of tRNA. In contrast, the Trm10p orthologue from the crenarchaeon Sulfolobus acidocaldarius forms ...
While a number of aminoacyl tRNA synthetase (aaRS):tRNA pairs have been engineered to alter or expand the genetic code, only the Methanococcus jannaschii tyrosyl tRNA synthetase and tRNA have been used extensively in bacteria, limiting the types and numbers of unnatural amino acids that can be utilized at any one time to expand the ...
The genes for 22 tRNA species from Acholeplasma laidawii, belonging to the class Mollicutes (Mycoplasmas), have been cloned and sequenced. Sixteen genes are organized in 3 clusters consisting of eleven, three and two tRNA genes, respectively, and the other 6 genes exist as a single gene. The arrangement of tRNA genes in the 11-gene, ...
The selection of cognate tRNAs during translation is specified by a kinetic discrimination mechanism driven by distinct structural states of the ribosome. While the biochemical steps that drive the tRNA selection process have been carefully documented, it remains unclear how recognition of matched codon:anticodon helices in the small subunit facilitate ...
Adenosine to inosine editing at the wobble position allows decoding of multiple codons by a single tRNA. This reaction is catalyzed by adenosine deaminases acting on tRNA (ADATs) and is essential for viability. In bacteria, the anticodon-specific enzyme is a homodimer that recognizes a single tRNA substrate (tRNA(Arg)(ACG)) and can ...
Several aspects of the genetic code are reviewed. Chemical modifications of bases of the anticodon loop in the transfer RNA, suppression of tRNA by mutants. Phenotypic suppression and codon-anticodon recognition are discussed with emphasis on the accuracy...
National Technical Information Service (NTIS)
Recognition of an amino acid-imbalanced diet (IMB) is thought to occur in the anterior piriform cortex (APC) of the brain in response to a decrease in the limiting amino acid. We hypothesized that tRNA charging is decreased after ingestion of IMB and that this is part of the mechanism by which a decrease in the limiting amino acid is recognized. We ...
Among the tRNA population of the archaeal parasite Nanoarchaeum equitans are five species assembled from separate 5? and 3? tRNA halves and four species derived from tRNA precursors containing introns. In both groups an intervening sequence element must be removed during tRNA maturation. A bulge�helix�bulge ...
Among the tRNA population of the archaeal parasite Nanoarchaeum equitans are five species assembled from separate 5' and 3' tRNA halves and four species derived from tRNA precursors containing introns. In both groups an intervening sequence element must be removed during tRNA maturation. A bulge-helix-bulge (BHB) ...
In order to further elucidate the mechanism of tRNA methylase-tRNA intreaction the methylation of some individual tRNAs separately and by pairs was performed. In conditions of tRNA excess the methylation rates of positionally analogous nucleotides in tRNA molecules are not summed up when two substrates are simultaneously present in the ...
Provide accurate speech recognition accessible via user interface device. ... access to speech recognition engine for voice control of systems. ...
NASA Website
SummaryEscherichia coli strains displaying hyper-accurate (restrictive) and ribosomal ambiguity (ram) phenotypes have long been associated with alterations in rpsL and rpsD/rpsE, respectively. Crystallographic evidence shows the ribosomal proteins S12 and S4/S5 (corresponding to these genes) to be located in separate regions of the small ribosomal subunit that are important ...
A full understanding of the mechanism of post- transcriptional regulation requires more than simple two- state prediction (binding or not binding) for RNA binding proteins. Here we report a sequence-based technique dedicated for predicting complex structures of protein and RNA by combining fold recognition with binding affinity prediction. The method not only provides a highly ...
One of the primary challenges in this quest is the accurate characterization of phytoplankton physiological variability. Recognition of this limitation was ...
Despite the prior lack of third-party testing of iris matching recognition, the conventional wisdom in the biometrics community has been that iris recognition is highly accurate--even the most accurate biometric. One of many examples of this belief is a c...
Hypermodifications near the anticodon of tRNA are fundamental for the efficiency and fidelity of protein synthesis. Dimethylallyltransferase (DMATase) catalyzes transfer of a dimethylallyl moiety from dimethylallyl pyrophosphate to N6 of A37 in certain tRNAs. Here we present the crystal structures of Saccharomyces cerevisiae DMATase�tRNACys complex in ...
Transfer RNA (tRNA) is produced as a precursor molecule that needs to be processed at its 3' and 5' ends. Ribonuclease P is the sole endonuclease responsible for processing the 5' end of tRNA by cleaving the precursor and leading to tRNA maturation. It was one of the first catalytic RNA molecules identified ...
Energy Citations Database
Autonomous Shape Model Learning for Object Localization and Recognition Joseph Modayil and Benjamin object recognition and localization. The results are accurate to within sensor precision. I. INTRODUCTION of scans and poses, is useful for both object recognition and localization. The problem of aligning scans
E-print Network
Distributions of phosphate backbone-produced electrostatic potentials around several tRNAs were calculated by solving the nonlinear Poisson-Boltzmann equation. The tRNAs were either free or bound to the proteins involved in translation: aminoacyl-tRNA and elongation factor EF-Tu. We identified several regions of strong negative potential related to typical structural patterns of ...
RNA editing changes the coding/decoding information relayed by transcripts via nucleotide insertion, deletion, or conversion. Editing of tRNA anticodons by deamination of adenine to inosine is used both by eukaryotes and prokaryotes to expand the decoding capacity of individual tRNAs. This limits the number of tRNA species required for codon-anticodon ...
Transfer RNA (tRNA) is a central genetic element in the decoding of genome information for all of Earth's life forms. Nevertheless, there are a great number of missing tRNAs that have been left without examination, especially in microbial genomes. Two tRNA gene families remarkable in their structure and expression mechanism have been reported: split and ...
Modification of the cytidine in the first anticodon position of the AUA decoding tRNA(Ile) (tRNA2(Ile)) of bacteria and archaea is essential for this tRNA to read the isoleucine codon AUA and to differentiate between AUA and the methionine codon AUG. To identify the modified cytidine in archaea, we have purified this tRNA species from ...
Ribosomes translate genetic information encoded by messenger RNAs (mRNAs) into proteins. Accurate decoding by the ribosome depends on the proper interaction between the mRNA codon and the anticodon of transfer RNA (tRNA). tRNAs from all kingdoms of life are enzymatically modified at distinct sites, particularly in and near the anticodon. Yet, the role of ...
The selection of aminoacyl-tRNAs by the ribosome is a fundamental step in the elongation cycle of protein synthesis. tRNA selection is a multistep process that ensures only correct aminoacyltRNAs are accepted, while incorrect aminoacyl-tRNAs are rejected. A key step in tRNA selection is the formation of base pairs between the anticodon of the ...
Apr 21, 2011 ... Provide accurate speech recognition accessible via user interface devices. 4. Include a software developer's kit to support development of ...
The genetic code is degenerate, in that 20 amino acids are encoded by 61 triplet codes. In 1966, Francis Crick hypothesized that the cell's limited number of tRNAs decoded the genome by recognizing more than one codon. The ambiguity of that recognition resided in the third base-pair, giving rise to the Wobble Hypothesis. Post-transcriptional modifications at ...
We have used Rp-phosphorothioate modifications and a binding interference assay to analyse the role of phosphate oxygens in tRNA recognition by Escherichia coli ribonuclease P (RNase P) RNA. Total (100%) Rp-phosphorothioate modification at A, C or G positions of RNase P RNA strongly impaired tRNA binding and pre-tRNA processing, while ...
Ribonuclease (RNase) P is the universal ribozyme responsible for 5?-end tRNA processing. We report the crystal structure of the Thermotoga maritima RNase P holoenzyme in complex with tRNAPhe. The 154 kDa complex consists of a large catalytic RNA (P RNA), a small protein cofactor, and mature tRNA. The structure shows that RNA-RNA ...
The specific aminoacylation of RNA oligonucleotides whose sequences are based on the acceptor stems of tRNAs can be viewed as an operational RNA code for amino acids that may be related to the development of the genetic code. Many synthetases also have direct interactions with tRNA anticodon triplets and, in some cases, these interactions are thought to be essential for ...
A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.
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A robotic CCD microscope and procedures to automate crystal recognition are studied. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of sm...
The objective of this research was to develop accurate mathematical models of speech sounds for the purpose of large-vocabulary continuous speech recognition. The research focussed on three areas: developing better speech models to improve recognition acc...
Being able to accurately estimate an object's pose (location) in an image is important for practical implementations and applications of object recognition. Recognition algorithms often trade off accuracy of the pose estimate for efficiency -- usually res...
claimed to be unaware of memory retrieval. This `implicit recognition' was associated with frontal that produce implicit memory can be operative in standard recognition tests. People can accurately discriminate and implicit memory have shaped memory research ever since their seminal descriptions in individuals
A method is described for indirect electron microscopic visualization and mapping of tRNA and other short transcripts hybridized to DNA. This method depends upon the attachment of the electron-dense protein ferritin to the RNA, the binding being mediated by the remarkably strong association of the egg white protein avidin with biotin. Biotin is covalently attached to the 3' ...
Infrared and Raman spectroscopy is useful for studying helical conformations of polypeptides, which are determined by molecular structure parameters. Nuclear magnetic resonance spectroscopy, as well as X-ray analysis, is now established to be important for conformation studies of proteins and nucleic acids in solution. This article is mainly concerned with the conformational aspect and function ...
This book contains 36 papers. Some of the titles are: Site-specific cleavage of DNA at 8-, 9-, and 10-bp sequences; The use of DNA methylases to alter the apparent recognition specificities of restriction endonucleases; Random cloning and sequencing by the M13/Dideoxynucleotide chain termination method; Solid-phase methods for sequencing of oligodeoxynucleotides and DNA; and ...
The methylation of the ribose 2?-OH of RNA occurs widely in nature and in all stable RNAs and occurs at five positions in yeast tRNA. 2?-O-methylation of tRNA at position 4 is interesting because it occurs in the acceptor stem (which is normally undermodified), it is the only 2?-O-methylation that occurs in the middle of a duplex region in ...
The tRNA:m22G10 methyltransferase of Pyrococus abyssi (PAB1283, a member of COG1041) catalyzes the N2,N2-dimethylation of guanosine at position 10 in tRNA. Boundaries of its THUMP (THioUridine synthases, RNA Methyltransferases and Pseudo-uridine synthases)�containing N-terminal domain ...
Wybutosine (yW) is a hypermodified nucleoside found in position 37 of tRNAPhe, and is essential for correct phenylalanine codon translation. yW derivatives widely exist in eukaryotes and archaea, and their chemical structures have many species-specific variations. Among them, its hydroxylated derivative, hydroxywybutosine (OHyW), is found in eukaryotes including human, but ...
Bacterial tyrosyl-tRNA synthetases (TyrRS) possess a flexibly linked C-terminal domain of ?80 residues, which has hitherto been disordered in crystal structures of the enzyme. We have determined the structure of Thermus thermophilus TyrRS at 2.0�? reso lution in a crystal form in which the C-terminal domain is ordered, and confirm that the fold is similar to part of the C-terminal domain of ...
Mutation frequency decline is the rapid and irreversible decline in the suppressor mutation frequency of Escherichia coli cells if the cells are kept in nongrowth media immediately following the mutagenic treatment. The gene mfd, which is necessary for mutation frequency decline, encodes a protein of 130 kDa which couples transcription to excision repair by binding to RNA polymerase and to UvrA, ...
An essay for the Halobacterium volcanii tRNATrp intron endonuclease has been developed. This enzyme accurately cleaves the H. volcanii intron containing tRNATrp substrates, but does not act on a typical eukaryotic intron-containing precursor, yeast pretRN...
O-Phosphoseryl-tRNA kinase (PSTK) is the key enzyme in recruiting selenocysteine (Sec) to the genetic code of archaea and eukaryotes. The enzyme phosphorylates Ser-tRNA(Sec) to produce O-phosphoseryl-tRNA(Sec) (Sep-tRNA(Sec)) that is then converted to Sec-tRNA(Sec) by Sep-tRNA:Sec-tRNA synthase. Earlier we reported the structure of the Methanocaldococcus jannaschii PSTK (MjPSTK) complexed with ...
O-Phosphoseryl-tRNA kinase (PSTK) is the key enzyme in recruiting selenocysteine (Sec) to the genetic code of archaea and eukaryotes. The enzyme phosphorylates Ser-tRNASec to produce O-phosphoseryl-tRNASec (Sep-tRNASec) that is then converted to Sec-tRNASec by Sep-tRNA:Sec-tRNA synthase. Earlier we reported ...
Nowadays, pedestrian recognition in far-infrared images toward realizing a night vision system becomes a hot topic. However, sufficient performance could not be achieved by conventional schemes for pedestrian recognition in farinfrared images. Since the properties of far-infrared images are different from visible images, it is not known what kind of scheme ...
In addition to its role in tRNA aminoacylation, Escherichia coli threonyl-tRNA synthetase is a regulatory protein which binds a site, called the operator, located in the leader of its own mRNA and inhibits translational initiation by competing with ribosome binding. This work shows that the two essential steps of regulation, operator recognition and ...
A novel aminoacyl-tRNA synthetase that contains an iron�sulfur cluster in the tRNA anticodon-binding region and efficiently charges tRNA with tryptophan has been found in Thermotoga maritima. The crystal structure of TmTrpRS (tryptophanyl-tRNA synthetase; TrpRS; EC 6.1.1.2) reveals an iron�sulfur [4Fe��4S] cluster bound to the ...
A novel aminoacyl-tRNA synthetase that contains an iron-sulfur cluster in the tRNA anticodon-binding region and efficiently charges tRNA with tryptophan has been found in Thermotoga maritima. The crystal structure of TmTrpRS (tryptophanyl-tRNA synthetase; TrpRS; EC 6.1.1.2) reveals an iron-sulfur [4Fe-4S] cluster bound to the tRNA ...
These studies show that only 10 out of 36 mitochondrial tRNAs hybridize to mtDNA. Consistent with previous observations, Arg, Ile, Lys, Val tRNAs must be imported cytoplasmic tRNAs, since these tRNAs do not hybridize to mtDNA. The evident indicates that these imported tRNAs in Tetrahymena mitochondria are not contaminating cytoplasmic tRNAs in our mitochondrial preparations. The conclusion that ...
Using random mutagenesis and a genetic screening in yeast, we isolated 26 mutations that inactivate Saccharomyces cerevisiae arginyl-tRNA synthetase (ArgRS). The mutations were identified and the kinetic parameters of the corresponding proteins were tested after purification of the expression products in Escherichia coli. The effects were interpreted in the light of the crystal structure of ArgRS. ...
Protein structure networks are constructed for the identification of long range signaling pathways in cysteinyl tRNA synthetase (CysRS). Molecular dynamics simulation trajectory of CysRS-ligand complexes were used to determine conformational ensembles in order to gain insight into the allosteric signaling paths. Communication paths between the anticodon-binding region and the ...
Contradicting the common assumption that accurate recognition reflects explicit-memory processing, we describe evidence for recognition lacking two hallmark explicit-memory features: awareness of memory retrieval and facilitation by attentive encoding. Kaleidoscope images were encoded in conjunction with an attentional diversion and ...
We have analyzed complexes between tRNA and E. coli M1 RNA by electrophoresis in non-denaturing polyacrylamide gels. The RNA subunit of E. coli RNase P formed a specific complex with mature tRNA molecules. A derivative of the tRNA(Gly), endowed with the intron of yeast tRNA(ile) (60 nt), was employed to improve separation of complexed and unbound M1 RNA. ...
Transfer RNA (tRNA) is an essential component of the cell's translation apparatus. These RNA strands contain the anticodon for a given amino acid, and when "charged" with that amino acid are termed aminoacyl-tRNA. Aminoacylation, which occurs exclusively at one of the 3'-terminal hydroxyl groups of tRNA, is catalyzed by a family of enzymes called ...
Histidine transfer RNA (tRNA) is unique among tRNA species as it carries an additional nucleotide at its 5' terminus. This unusual G(-1) residue is the major tRNA(His) identity element, and essential for recognition by the cognate histidyl-tRNA synthetase to allow efficient His-tRNA(His) formation. In many organisms G(-1) is added ...
The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the ...
ERIC Educational Resources Information Center
A significantly improved molecular model of yeast initiator tRNA (ytRNA(iMet) has been prepared that gives insight into the structural basis of eukaryotic initiator tRNA's unique function. This study was made possible by X-ray data collected at synchrotron radiation sources with the newly developed technologies of 'imaging plates' and 'storage phosphors'. ...
A rapid quantitative method for enzymatic hydrolysis of microgram amounts of tRNA has been developed, specifically to take full advantage of our precise, accurate, and selective reversed-phase high-performance liquid chromatographic (HPLC) system for separation and measurement of the major and modified nucleosides in tRNA. After study ...
Professor John Daugman of the University of Cambridge Computer Laboratory is the author of this paper on iris recognition. It examines the characteristics of the human iris from a statistical perspective in order to estimate the requirements for accurate identification. Many complex issues of pattern recognition are addressed, such as ...
NSDL National Science Digital Library
Car-Rec: A Real Time Car Recognition System Daniel Marcus Jang and Matthew Turk University. The resulting system is applied to the domain of car recognition and achieves accurate (> 90%) and real-time performance when searching databases containing thou- sands of images. 1. Introduction Car recognition
This research aims to develop new and more accurate stochastic models for speaker-independent continuous speech recognition, by extending previous work in segment-based modeling and by introducing a new hierarchical approach to representing intra-utteranc...
Correlation-based methods for automatic image recognition are implemented using a position-sensitive, photon-counting detection system. It is demonstrated that the information provided by a small number of detected photoevents can be used to accurately es...
Most artificial intelligence systems today work on simple problems and artificial domains because they rely on the accurate sensing of the task world. Object recognition is a crucial part of the sensing challenge and machine learning stands in a position ...
Psychological research indicates that humans recognize faces of their own race more accurately than faces of other races. This other-race effect occurs for algorithms tested in the Face Recognition Vendor Test 2006. We report results for a Western algorit...
A key problem for face recognition has been accurate identification under variable illumination conditions. Conventional video cameras sense reflected light so that image gray values are a product of both intrinsic skin reflectivity and external incident ...
... Abstract : The report describes a scheme which permits an on-line computer user to print text naturally, and have it recognized accurately. ...
DTIC Science & Technology
Service Level Indicator: 98% Awards /recognition item/supplies delivered to Center Awards POC/recipient accurately and on-time as negotiated with the ...
Munitions that can accurately attack beyond the line of sight are necessary for the army of the near future, but require simultaneous advances in millimeter seekers and software for target recognition and guidance. 15 references.
The recognition heuristic is a prime example of how, by exploiting a match between mind and environment, a simple mental strategy can lead to efficient decision making. The proposal of the heuristic initiated a debate about the processes underlying the use of recognition in decision making. We review research addressing four key aspects of the ...
We determined the nature of the fourth nucleotide from the 3?-end of several Escherichia coli tRNAs, and tabulated these results with the same data for all known tRNA sequences. We find a striking constancy of the fourth nucleotide in tRNAs specific for a given amino acid. Furthermore, tRNAs specific for chemically related amino acids are very likely to have the same ...
A randomly generated mutation in Escherichia coli alanine tRNA synthetase compensates for a mutation in its cognate tRNA. The enzyme's mutation occurs next to a Cys-X2-Cys-X6-His-X2-His metal-binding motif that is distinct from the zinc finger motif found in some DNA-binding proteins. Instead, the synthetase's metal binding domain resembles the ...
Face recognition based on 2D images is a difficult problem, because the illumination, pose and expression changes in the images create great statistical differences and the identity of the face itself becomes shadowed by these factors. 3D face recognition has the potential to overcome feature localization, pose and illumination problems, and it can be used ...
The number and location of pseudouridine residues in Escherichia coli 16S ribosomal RNA has been determined by a combination of direct and indirect methods. Only one residue was found, at position 516. This site is at the 5'-end of one of the three most highly conserved long sequences of this RNA molecule. A number of experimental findings have strongly implicated this loop in the fidelity of ...
The discovery of non-universal genetic codes in several mitochondria and nuclear systems during the past ten years has necessitated a reconsideration of the concept that the genetic code is universal and frozen, as was once believed. Here, the flexibility of the relationship between codons and amino acids is discussed on the basis of the distribution of non-universal genetic codes in various ...
This study examined 30 experienced basketball players' recognition accuracy by sex, playing position (guard, forward, and center), and situations in the game of basketball. The study used a perceptual cognitive paradigm in which subjects viewed slides of structured and unstructured game situations and accurately recognized the presence or absence of the ...
Archaeal and eukaryotic tRNA (N(2)-, N(2)-guanine) dimethyltransferase (Trm1) produces N(2)-, N(2)-dimethylguanine at position 26 in tRNA. In contrast, Trm1 from Aquifex aeolicus, a hyper-thermophilic eubacterium, modifies G27 as well as G26. Here, a gel-mobility shift assay revealed that the T-arm in tRNA is the binding site of A. ...
The specific aminoacylation of tRNA by tyrosyl-tRNA synthetases (TyrRSs) relies on the identity determinants in the cognate tRNATyrs. We have determined the crystal structure of Saccharomyces cerevisiae TyrRS (SceTyrRS) complexed with a Tyr-AMP analog and the native tRNATyr(G?A). Structural information for ...
We analyze the protein�RNA interfaces in 81 transient binary complexes taken from the Protein Data Bank. Those with tRNA or duplex RNA are larger than with single-stranded RNA, and comparable in size to protein�DNA interfaces. The protein side bears a strong positive electrostatic potential and resembles protein�DNA interfaces in its amino acid composition. On the RNA ...
In this paper, we define meta-recognition, a performance prediction method for recognition algorithms, and examine the theoretical basis for its post-recognition score analysis form through the use of the statistical extreme value theory (EVT). The ability to predict the performance of a recognition system based on ...
The molecular mechanisms underlying the primitive translational apparatus have been studied in light of present day protein biosynthesis. Using the structural information available from the contemporary system as a key to its function, both the structural necessities for an early adaptor and the multipoint recognition properties of such adaptors have been investigated. This ...
35S-labelled tRNA from Escherichia coli was treated with chemical reagents such as CNBr, H2O2, NH2OH, I2, HNO2, KMnO4 and NaIO4, under mild conditions where the four major bases were not ...
The 2.2�? crystal structure of a ternary complex formed by yeast arginyl-tRNA synthetase and its cognate tRNAArg in the presence of the l-arginine substrate highlights new atomic features used for specific substrate recognition. This first example of an active complex formed by a class�Ia aminoacyl-tRNA synthetase and its natural cognate ...
N2,N2-dimethylguanosine (m2(2)G) is a characteristic nucleoside that is found in the bend between the dihydro-uridine (D) stem and the anticodon (AC) stem in over 80% of the eukaryotic tRNA species having guanosine at position 26 (G26). However, since a few eukaryotic tRNAs have an unmodified G in that position, G26 is a necessary but not a sufficient condition for ...
In the past decade, tremendous advances in the state of the art of automatic speech recognition by machine have taken place. A reduction in the word error rate by more than a factor of 5 and an increase in recognition speeds by several orders of magnitude (brought about by a combination of faster recognition search algorithms and more ...
We present a method of interactive training for handwriting recognition in collections of documents. As the user transcribes (labels) the words in the training set, words are automatically skipped if they appear to match words that are already transcribed. By reducing the amount of redundant training, better coverage of the data is achieved, resulting in more ...
Document recognition advances have improved the lives of people with print disabilities, by providing accessible documents. This invited paper provides perspectives on the author's career progression from document recognition professional to social entrepreneur applying this technology to help people with disabilities. Starting with initial thoughts about ...
Among all types of RNA, tRNA is unique given that it possesses the largest assortment and abundance of modified nucleosides. The methylation at N1 of adenosine 58 is a conserved modification, occurring in bacterial, archaeal, and eukaryotic tRNAs. In the yeast Saccharomyces cerevisiae, the tRNA 1-methyladenosine 58 ...
In this paper, a kind of classifier based on support vector machine (SVM) is designed for infrared target recognition. In allusion to the problem how to choose kernel parameter and error penalty factor, quantum genetic algorithm (QGA) is used to optimize the parameters of SVM model, it overcomes the shortcoming of determining its parameters after trial and error in the past. ...
Bacterial and eukaryotic transfer RNAs that decode codons starting with uridine have a hydrophobically-hypermodified adenosine at the position 37 (A37) adjacent to the 3?-end of the anticodon, which is essential for efficient and highly accurate protein translation by the ribosome. However, it remains unclear how the corresponding tRNAs are selected to ...
Modification of the cytidine in the first anticodon position of the AUA decoding tRNAIle () of bacteria and archaea is essential for this tRNA to read the isoleucine codon AUA and to differentiate between AUA and the methionine codon AUG. To identify the modified cytidine in archaea, we have purified this tRNA species from Haloarcula ...
We have done a systematic study on the contribution of the single-stranded NCCA end (where N is any nucleotide) to the stability of the aminoacyl stem of tRNA. A 7-bp RNA duplex with the single-strand ACCA 3' terminus derived from the aminoacyl stem of Escherichia coli tRNA(Ala) and several chemically synthesized sequence variants are characterized by proton NMR and ...
Infantile cardiomyopathies are devastating fatal disorders of the neonatal period or the first year of life. Mitochondrial dysfunction is a common cause of this group of diseases, but the underlying gene defects have been characterized in only a minority of cases, because tissue specificity of the manifestation hampers functional cloning and the heterogeneity of causative factors hinders ...
The correlation between the in vivo functioning and the in vitro behavior of the thermolabile alanyl-transfer ribonucleic acid (tRNA) synthetase (ARS) of Escherichia coli strain BM113 is presented. As a measure for the ARS activity inside the cell, the amount of acylated tRNAala in vivo was determined. The rapid drop of the per cent ...
Pyrrolysine (Pyl), the 22nd natural amino acid and genetically encoded by UAG, becomes attached to its cognate tRNA by pyrrolysyl-tRNA synthetase (PylRS). We have determined three crystal structures of the Methanosarcina mazei PylRS complexed with either AMP�PNP, Pyl�AMP plus pyrophosphate, or the Pyl analogue N-?-[(cylopentyloxy)carbonyl]-l-lysine plus ATP. The structures ...
Pyrrolysine (Pyl), the 22nd natural amino acid and genetically encoded by UAG, becomes attached to its cognate tRNA by pyrrolysyl-tRNA synthetase (PylRS). We have determined three crystal structures of the Methanosarcina mazei PylRS complexed with either AMP-PNP, Pyl-AMP plus pyrophosphate, or the Pyl analogue N-e-[(cylopentyloxy)carbonyl]-l-lysine plus ATP. The structures ...
Crystal structures of the 30S ribosomal subunit in complex with messenger RNA and cognate transfer RNA in the A site, both in the presence and absence of the antibiotic paromomycin, have been solved at between 3.1 and 3.3 angstroms resolution. Cognate transfer RNA (tRNA) binding induces global domain movements of the 30S subunit and changes in the conformation of the ...
A special methionine tRNA (tRNAi) is universally required to initiate translation. Amongst species a tRNAi structural conservation is most apparent in the anticodon and T arms of the molecule but extends into the variable loop and the 3' strand of the D stem. This suggested that they could share a similar ancestral or current function in initiation of translation. We report ...
During initiation of bacterial protein synthesis, messenger RNA and fMet-tRNAfMet bind to the 30S ribosomal subunit together with initiation factors IF1, IF2, and IF3. Docking of the 30S preinitiation complex to the 50S ribosomal subunit results in a peptidyl-transfer competent 70S ribosome. Initiation with an elongator tRNA may lead to frameshift and an aberrant N-terminal ...
SummaryHigher eukaryote tRNA synthetases have expanded functions with roles in the assembly of biological systems. New functions come from enlarged, more differentiated structures that were adapted to fit with the essential aminoacylation function. How those adaptations affect catalytic mechanism is not known. Presented here is the structure of a catalytically active natural ...
To elucidate the mechanism involved in the transcription initiation process in mitochondria of dicotyledonous plants, an in vitro transcription system was established for pea (Pisum sativum L.). The partially purified mitochondrial protein extract initiates transcription on homologous pea templates as well as on heterologous mitochondrial DNA from other dicot plant species. In vitro transcription ...
Recent years have seen a growing recognition of the role of goal and affect recognition in intelligent tutoring systems. Goal recognition is the task of inferring users' goals from a sequence of observations of their actions. Because of the uncertainty inherent in every facet of human computer interaction, goal ...
The N(6)-(isopentenyl)adenosine (i(6)A) modification of some tRNAs at position A37 is found in all kingdoms and facilitates codon-specific mRNA decoding, but occurs in different subsets of tRNAs in different species. Here we examine yeasts' tRNA isopentenyltransferases (i.e., dimethylallyltransferase, DMATase, members of the ?(2)-isopentenylpyrophosphate transferase, IPPT ...
Seryl-tRNA synthetase (SerRS) from methanogenic archaeon Methanosarcina barkeri, contains an idiosyncratic N-terminal domain, composed of an antiparallel ?-sheet capped by a helical bundle, connected to the catalytic core by a short linker peptide. It is very different from the coiled-coil tRNA binding domain in bacterial-type SerRS. Because the crystal structure of the ...
Pattern recognition was an important goal in the early work on artificial neural networks. Without arousing dramatic speculation, the paper describes, how a "natural" method of dealing with the configuration of the input layer can considerably improve learning behaviour and classification rate of a modified multi-layered perception with backpropagation of the error learning ...
The essential midline symmetry of human faces is shown to play a key role in facial coding and recognition. This also has deep and important connections with recent explorations of the organization of primate cortex, as well as human psychophysical experiments. Evidence is presented that the dimension of face recognition space for human faces is ...
This paper presents the application of genetic algorithm for the integration of neural classifiers combined in the ensemble for the accurate recognition of heartbeat types on the basis of ECG registration. The idea presented in this paper is that using many classifiers arranged in the form of ensemble leads to the increased accuracy of the ...
Camera Assisted Visual Interactive Recognition (CAVIAR) draws on sequential pattern recognition, image database, expert systems, pen computing, and digital camera technology. It is designed to recognize wild flowers and other families of similar objects more accurately than machine vision and faster than most laypersons. The novelty of ...