Sample records for harbors endonuclease activity

  1. Selective inhibition by harmane of the apurinic apyrimidinic endonuclease activity of phage T4-induced UV endonuclease.

    PubMed

    Warner, H R; Persson, M L; Bensen, R J; Mosbaugh, D W; Linn, S

    1981-11-25

    1-Methyl-9H-pyrido-[3,4-b]indole (harmane) inhibits the apurinic/apyrimidinic (AP) endonuclease activity of the UV endonuclease induced by phage T4, whereas it stimulates the pyrimidine dimer-DNA glycosylase activity of that enzyme. E. coli endonuclease IV, E. coli endonuclease VI (the AP endonuclease activity associated with E. coli exonuclease III), and E. coli uracil-DNA glycosylase were not inhibited by harmane. Human fibroblast AP endonucleases I and II also were only slightly inhibited. Therefore, harmane is neither a general inhibitor of AP endonucleases, nor a general inhibitor of Class I AP endonucleases which incise DNA on the 3'-side of AP sites. However, E. coli endonuclease III and its associated dihydroxythymine-DNA glycosylase activity were both inhibited by harmane. This observation suggests that harmane may inhibit only AP endonucleases which have associated glycosylase activities.

  2. Selective inhibition by harmane of the apurinic apyrimidinic endonuclease activity of phage T4-induced UV endonuclease.

    PubMed Central

    Warner, H R; Persson, M L; Bensen, R J; Mosbaugh, D W; Linn, S

    1981-01-01

    1-Methyl-9H-pyrido-[3,4-b]indole (harmane) inhibits the apurinic/apyrimidinic (AP) endonuclease activity of the UV endonuclease induced by phage T4, whereas it stimulates the pyrimidine dimer-DNA glycosylase activity of that enzyme. E. coli endonuclease IV, E. coli endonuclease VI (the AP endonuclease activity associated with E. coli exonuclease III), and E. coli uracil-DNA glycosylase were not inhibited by harmane. Human fibroblast AP endonucleases I and II also were only slightly inhibited. Therefore, harmane is neither a general inhibitor of AP endonucleases, nor a general inhibitor of Class I AP endonucleases which incise DNA on the 3'-side of AP sites. However, E. coli endonuclease III and its associated dihydroxythymine-DNA glycosylase activity were both inhibited by harmane. This observation suggests that harmane may inhibit only AP endonucleases which have associated glycosylase activities. PMID:6273822

  3. Crystal structure of an avian influenza polymerase PA[subscript N] reveals an endonuclease active site

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

    Yuan, Puwei; Bartlam, Mark; Lou, Zhiyong

    2009-11-10

    The heterotrimeric influenza virus polymerase, containing the PA, PB1 and PB2 proteins, catalyses viral RNA replication and transcription in the nucleus of infected cells. PB1 holds the polymerase active site and reportedly harbours endonuclease activity, whereas PB2 is responsible for cap binding. The PA amino terminus is understood to be the major functional part of the PA protein and has been implicated in several roles, including endonuclease and protease activities as well as viral RNA/complementary RNA promoter binding. Here we report the 2.2 angstrom (A) crystal structure of the N-terminal 197 residues of PA, termed PA(N), from an avian influenzamore » H5N1 virus. The PA(N) structure has an alpha/beta architecture and reveals a bound magnesium ion coordinated by a motif similar to the (P)DX(N)(D/E)XK motif characteristic of many endonucleases. Structural comparisons and mutagenesis analysis of the motif identified in PA(N) provide further evidence that PA(N) holds an endonuclease active site. Furthermore, functional analysis with in vivo ribonucleoprotein reconstitution and direct in vitro endonuclease assays strongly suggest that PA(N) holds the endonuclease active site and has critical roles in endonuclease activity of the influenza virus polymerase, rather than PB1. The high conservation of this endonuclease active site among influenza strains indicates that PA(N) is an important target for the design of new anti-influenza therapeutics.« less

  4. PMS2 endonuclease activity has distinct biological functions and is essential for genome maintenance.

    PubMed

    van Oers, Johanna M M; Roa, Sergio; Werling, Uwe; Liu, Yiyong; Genschel, Jochen; Hou, Harry; Sellers, Rani S; Modrich, Paul; Scharff, Matthew D; Edelmann, Winfried

    2010-07-27

    The DNA mismatch repair protein PMS2 was recently found to encode a novel endonuclease activity. To determine the biological functions of this activity in mammals, we generated endonuclease-deficient Pms2E702K knock-in mice. Pms2EK/EK mice displayed increased genomic mutation rates and a strong cancer predisposition. In addition, class switch recombination, but not somatic hypermutation, was impaired in Pms2EK/EK B cells, indicating a specific role in Ig diversity. In contrast to Pms2-/- mice, Pms2EK/EK male mice were fertile, indicating that this activity is dispensable in spermatogenesis. Therefore, the PMS2 endonuclease activity has distinct biological functions and is essential for genome maintenance and tumor suppression.

  5. PMS2 endonuclease activity has distinct biological functions and is essential for genome maintenance

    PubMed Central

    van Oers, Johanna M. M.; Roa, Sergio; Werling, Uwe; Liu, Yiyong; Genschel, Jochen; Sellers, Rani S.; Modrich, Paul; Scharff, Matthew D.; Edelmann, Winfried

    2010-01-01

    The DNA mismatch repair protein PMS2 was recently found to encode a novel endonuclease activity. To determine the biological functions of this activity in mammals, we generated endonuclease-deficient Pms2E702K knock-in mice. Pms2EK/EK mice displayed increased genomic mutation rates and a strong cancer predisposition. In addition, class switch recombination, but not somatic hypermutation, was impaired in Pms2EK/EK B cells, indicating a specific role in Ig diversity. In contrast to Pms2−/− mice, Pms2EK/EK male mice were fertile, indicating that this activity is dispensable in spermatogenesis. Therefore, the PMS2 endonuclease activity has distinct biological functions and is essential for genome maintenance and tumor suppression. PMID:20624957

  6. Crystal structure and DNA repair activities of the AP endonuclease from Leishmania major.

    PubMed

    Vidal, Antonio E; Harkiolaki, Maria; Gallego, Claribel; Castillo-Acosta, Victor M; Ruiz-Pérez, Luis M; Wilson, Keith; González-Pacanowska, Dolores

    2007-11-02

    Apurinic/apyrimidinic endonucleases initiate the repair of abasic sites produced either spontaneously, from attack of bases by reactive oxygen species or as intermediates during base excision repair. The catalytic properties and crystal structure of Leishmania major apurinic/apyrimidinic endonuclease are described and compared with those of human APE1 and bacterial exonuclease III. The purified enzyme is shown to possess apurinic/apyrimidinic endonuclease activity of the same order as eukaryotic and prokaryotic counterparts and an equally robust 3'-phosphodiesterase activity. Consistent with this, expression of the L. major endonuclease confers resistance to both methyl methane sulphonate and H2O2 in Escherichia coli repair-deficient mutants while expression of the human homologue only reverts methyl methane sulphonate sensitivity. Structural analyses and modelling of the enzyme-DNA complex demonstrates a high degree of conservation to previously characterized homologues, although subtle differences in the active site geometry might account for the high 3'-phosphodiesterase activity. Our results confirm that the L. major's enzyme is a key element in mediating repair of apurinic/apyrimidinic sites and 3'-blocked termini and therefore must play an important role in the survival of kinetoplastid parasites after exposure to the highly oxidative environment within the host macrophage.

  7. Structure of the endonuclease IV homologue from Thermotoga maritima in the presence of active-site divalent metal ions

    PubMed Central

    Tomanicek, Stephen J.; Hughes, Ronny C.; Ng, Joseph D.; Coates, Leighton

    2010-01-01

    The most frequent lesion in DNA is at apurinic/apyrimidinic (AP) sites resulting from DNA-base losses. These AP-site lesions can stall DNA replication and lead to genome instability if left unrepaired. The AP endonucleases are an important class of enzymes that are involved in the repair of AP-site intermediates during damage-general DNA base-excision repair pathways. These enzymes hydrolytically cleave the 5′-phosphodiester bond at an AP site to generate a free 3′-­hydroxyl group and a 5′-terminal sugar phosphate using their AP nuclease activity. Specifically, Thermotoga maritima endonuclease IV is a member of the second conserved AP endonuclease family that includes Escherichia coli endonuclease IV, which is the archetype of the AP endonuclease superfamily. In order to more fully characterize the AP endonuclease family of enzymes, two X-­ray crystal structures of the T. maritima endonuclease IV homologue were determined in the presence of divalent metal ions bound in the active-site region. These structures of the T. maritima endonuclease IV homologue further revealed the use of the TIM-barrel fold and the trinuclear metal binding site as important highly conserved structural elements that are involved in DNA-binding and AP-site repair processes in the AP endonuclease superfamily. PMID:20823514

  8. PCNA function in the activation and strand direction of MutLα endonuclease in mismatch repair

    PubMed Central

    Pluciennik, Anna; Dzantiev, Leonid; Iyer, Ravi R.; Constantin, Nicoleta; Kadyrov, Farid A.; Modrich, Paul

    2010-01-01

    MutLα (MLH1–PMS2) is a latent endonuclease that is activated in a mismatch-, MutSα-, proliferating cell nuclear antigen (PCNA)-, replication factor C (RFC)-, and ATP-dependent manner, with nuclease action directed to the heteroduplex strand that contains a preexisting break. RFC depletion experiments and use of linear DNAs indicate that RFC function in endonuclease activation is limited to PCNA loading. Whereas nicked circular heteroduplex DNA is a good substrate for PCNA loading and for endonuclease activation on the incised strand, covalently closed, relaxed circular DNA is a poor substrate for both reactions. However, covalently closed supercoiled or bubble-containing relaxed heteroduplexes, which do support PCNA loading, also support MutLα activation, but in this case cleavage strand bias is largely abolished. Based on these findings we suggest that PCNA has two roles in MutLα function: The clamp is required for endonuclease activation, an effect that apparently involves interaction of the two proteins, and by virtue of its loading orientation, PCNA determines the strand direction of MutLα incision. These results also provide a potential mechanism for activation of mismatch repair on nonreplicating DNA, an effect that may have implications for the somatic phase of triplet repeat expansion. PMID:20713735

  9. Homing endonucleases from mobile group I introns: discovery to genome engineering

    PubMed Central

    2014-01-01

    Homing endonucleases are highly specific DNA cleaving enzymes that are encoded within genomes of all forms of microbial life including phage and eukaryotic organelles. These proteins drive the mobility and persistence of their own reading frames. The genes that encode homing endonucleases are often embedded within self-splicing elements such as group I introns, group II introns and inteins. This combination of molecular functions is mutually advantageous: the endonuclease activity allows surrounding introns and inteins to act as invasive DNA elements, while the splicing activity allows the endonuclease gene to invade a coding sequence without disrupting its product. Crystallographic analyses of representatives from all known homing endonuclease families have illustrated both their mechanisms of action and their evolutionary relationships to a wide range of host proteins. Several homing endonucleases have been completely redesigned and used for a variety of genome engineering applications. Recent efforts to augment homing endonucleases with auxiliary DNA recognition elements and/or nucleic acid processing factors has further accelerated their use for applications that demand exceptionally high specificity and activity. PMID:24589358

  10. The mismatch repair and meiotic recombination endonuclease Mlh1-Mlh3 is activated by polymer formation and can cleave DNA substrates in trans.

    PubMed

    Manhart, Carol M; Ni, Xiaodan; White, Martin A; Ortega, Joaquin; Surtees, Jennifer A; Alani, Eric

    2017-04-01

    Crossing over between homologs is initiated in meiotic prophase by the formation of DNA double-strand breaks that occur throughout the genome. In the major interference-responsive crossover pathway in baker's yeast, these breaks are resected to form 3' single-strand tails that participate in a homology search, ultimately forming double Holliday junctions (dHJs) that primarily include both homologs. These dHJs are resolved by endonuclease activity to form exclusively crossovers, which are critical for proper homolog segregation in Meiosis I. Recent genetic, biochemical, and molecular studies in yeast are consistent with the hypothesis of Mlh1-Mlh3 DNA mismatch repair complex acting as the major endonuclease activity that resolves dHJs into crossovers. However, the mechanism by which the Mlh1-Mlh3 endonuclease is activated is unknown. Here, we provide evidence that Mlh1-Mlh3 does not behave like a structure-specific endonuclease but forms polymers required to generate nicks in DNA. This conclusion is supported by DNA binding studies performed with different-sized substrates that contain or lack polymerization barriers and endonuclease assays performed with varying ratios of endonuclease-deficient and endonuclease-proficient Mlh1-Mlh3. In addition, Mlh1-Mlh3 can generate religatable double-strand breaks and form an active nucleoprotein complex that can nick DNA substrates in trans. Together these observations argue that Mlh1-Mlh3 may not act like a canonical, RuvC-like Holliday junction resolvase and support a novel model in which Mlh1-Mlh3 is loaded onto DNA to form an activated polymer that cleaves DNA.

  11. The mismatch repair and meiotic recombination endonuclease Mlh1-Mlh3 is activated by polymer formation and can cleave DNA substrates in trans

    PubMed Central

    Manhart, Carol M.; Ni, Xiaodan; White, Martin A.; Ortega, Joaquin; Surtees, Jennifer A.

    2017-01-01

    Crossing over between homologs is initiated in meiotic prophase by the formation of DNA double-strand breaks that occur throughout the genome. In the major interference-responsive crossover pathway in baker’s yeast, these breaks are resected to form 3' single-strand tails that participate in a homology search, ultimately forming double Holliday junctions (dHJs) that primarily include both homologs. These dHJs are resolved by endonuclease activity to form exclusively crossovers, which are critical for proper homolog segregation in Meiosis I. Recent genetic, biochemical, and molecular studies in yeast are consistent with the hypothesis of Mlh1-Mlh3 DNA mismatch repair complex acting as the major endonuclease activity that resolves dHJs into crossovers. However, the mechanism by which the Mlh1-Mlh3 endonuclease is activated is unknown. Here, we provide evidence that Mlh1-Mlh3 does not behave like a structure-specific endonuclease but forms polymers required to generate nicks in DNA. This conclusion is supported by DNA binding studies performed with different-sized substrates that contain or lack polymerization barriers and endonuclease assays performed with varying ratios of endonuclease-deficient and endonuclease-proficient Mlh1-Mlh3. In addition, Mlh1-Mlh3 can generate religatable double-strand breaks and form an active nucleoprotein complex that can nick DNA substrates in trans. Together these observations argue that Mlh1-Mlh3 may not act like a canonical, RuvC-like Holliday junction resolvase and support a novel model in which Mlh1-Mlh3 is loaded onto DNA to form an activated polymer that cleaves DNA. PMID:28453523

  12. Human Fanconi Anemia Complementation Group A Protein Stimulates the 5’ Flap Endonuclease Activity of FEN1

    PubMed Central

    Qian, Liangyue; Yuan, Fenghua; Rodriguez-Tello, Paola; Padgaonkar, Suyog; Zhang, Yanbin

    2013-01-01

    In eukaryotic cells, Flap endonuclease 1 (FEN1) is a major structure-specific endonuclease that processes 5’ flapped structures during maturation of lagging strand DNA synthesis, long patch base excision repair, and rescue of stalled replication forks. Here we report that fanconi anemia complementation group A protein (FANCA), a protein that recognizes 5’ flap structures and is involved in DNA repair and maintenance of replication forks, constantly stimulates FEN1-mediated incision of both DNA and RNA flaps. Kinetic analyses indicate that FANCA stimulates FEN1 by increasing the turnover rate of FEN1 and altering its substrate affinity. More importantly, six pathogenic FANCA mutants are significantly less efficient than the wild-type at stimulating FEN1 endonuclease activity, implicating that regulation of FEN1 by FANCA contributes to the maintenance of genomic stability. PMID:24349332

  13. RPA activates the XPF-ERCC1 endonuclease to initiate processing of DNA interstrand crosslinks.

    PubMed

    Abdullah, Ummi B; McGouran, Joanna F; Brolih, Sanja; Ptchelkine, Denis; El-Sagheer, Afaf H; Brown, Tom; McHugh, Peter J

    2017-07-14

    During replication-coupled DNA interstrand crosslink (ICL) repair, the XPF-ERCC1 endonuclease is required for the incisions that release, or "unhook", ICLs, but the mechanism of ICL unhooking remains largely unknown. Incisions are triggered when the nascent leading strand of a replication fork strikes the ICL Here, we report that while purified XPF-ERCC1 incises simple ICL-containing model replication fork structures, the presence of a nascent leading strand, modelling the effects of replication arrest, inhibits this activity. Strikingly, the addition of the single-stranded DNA (ssDNA)-binding replication protein A (RPA) selectively restores XPF-ERCC1 endonuclease activity on this structure. The 5'-3' exonuclease SNM1A can load from the XPF-ERCC1-RPA-induced incisions and digest past the crosslink to quantitatively complete the unhooking reaction. We postulate that these collaborative activities of XPF-ERCC1, RPA and SNM1A might explain how ICL unhooking is achieved in vivo . © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  14. The SalGI restriction endonuclease. Purification and properties

    PubMed Central

    Maxwell, Anthony; Halford, Stephen E.

    1982-01-01

    The type II restriction endonuclease SalGI has been purified to near homogeneity. At least 80% of the protein remaining after the final stage of the preparation is SalGI restriction endonuclease; no contaminating nucleases remain detectable. The principal form of the protein under both native and denaturing conditions is a monomer of Mr about 29000. The optimal conditions for both enzyme stability and enzyme activity have been determined. ImagesFig. 1. PMID:6285898

  15. Activation of Saccharomyces cerevisiae Mlh1-Pms1 Endonuclease in a Reconstituted Mismatch Repair System.

    PubMed

    Smith, Catherine E; Bowen, Nikki; Graham, William J; Goellner, Eva M; Srivatsan, Anjana; Kolodner, Richard D

    2015-08-28

    Previous studies reported the reconstitution of an Mlh1-Pms1-independent 5' nick-directed mismatch repair (MMR) reaction using Saccharomyces cerevisiae proteins. Here we describe the reconstitution of a mispair-dependent Mlh1-Pms1 endonuclease activation reaction requiring Msh2-Msh6 (or Msh2-Msh3), proliferating cell nuclear antigen (PCNA), and replication factor C (RFC) and a reconstituted Mlh1-Pms1-dependent 3' nick-directed MMR reaction requiring Msh2-Msh6 (or Msh2-Msh3), exonuclease 1 (Exo1), replication protein A (RPA), RFC, PCNA, and DNA polymerase δ. Both reactions required Mg(2+) and Mn(2+) for optimal activity. The MMR reaction also required two reaction stages in which the first stage required incubation of Mlh1-Pms1 with substrate DNA, with or without Msh2-Msh6 (or Msh2-Msh3), PCNA, and RFC but did not require nicking of the substrate, followed by a second stage in which other proteins were added. Analysis of different mutant proteins demonstrated that both reactions required a functional Mlh1-Pms1 endonuclease active site, as well as mispair recognition and Mlh1-Pms1 recruitment by Msh2-Msh6 but not sliding clamp formation. Mutant Mlh1-Pms1 and PCNA proteins that were defective for Exo1-independent but not Exo1-dependent MMR in vivo were partially defective in the Mlh1-Pms1 endonuclease and MMR reactions, suggesting that both reactions reflect the activation of Mlh1-Pms1 seen in Exo1-independent MMR in vivo. The availability of this reconstituted MMR reaction should now make it possible to better study both Exo1-independent and Exo1-dependent MMR. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Activation of Saccharomyces cerevisiae Mlh1-Pms1 Endonuclease in a Reconstituted Mismatch Repair System*

    PubMed Central

    Smith, Catherine E.; Bowen, Nikki; Graham, William J.; Goellner, Eva M.; Srivatsan, Anjana; Kolodner, Richard D.

    2015-01-01

    Previous studies reported the reconstitution of an Mlh1-Pms1-independent 5′ nick-directed mismatch repair (MMR) reaction using Saccharomyces cerevisiae proteins. Here we describe the reconstitution of a mispair-dependent Mlh1-Pms1 endonuclease activation reaction requiring Msh2-Msh6 (or Msh2-Msh3), proliferating cell nuclear antigen (PCNA), and replication factor C (RFC) and a reconstituted Mlh1-Pms1-dependent 3′ nick-directed MMR reaction requiring Msh2-Msh6 (or Msh2-Msh3), exonuclease 1 (Exo1), replication protein A (RPA), RFC, PCNA, and DNA polymerase δ. Both reactions required Mg2+ and Mn2+ for optimal activity. The MMR reaction also required two reaction stages in which the first stage required incubation of Mlh1-Pms1 with substrate DNA, with or without Msh2-Msh6 (or Msh2-Msh3), PCNA, and RFC but did not require nicking of the substrate, followed by a second stage in which other proteins were added. Analysis of different mutant proteins demonstrated that both reactions required a functional Mlh1-Pms1 endonuclease active site, as well as mispair recognition and Mlh1-Pms1 recruitment by Msh2-Msh6 but not sliding clamp formation. Mutant Mlh1-Pms1 and PCNA proteins that were defective for Exo1-independent but not Exo1-dependent MMR in vivo were partially defective in the Mlh1-Pms1 endonuclease and MMR reactions, suggesting that both reactions reflect the activation of Mlh1-Pms1 seen in Exo1-independent MMR in vivo. The availability of this reconstituted MMR reaction should now make it possible to better study both Exo1-independent and Exo1-dependent MMR. PMID:26170454

  17. Inteins, introns, and homing endonucleases: recent revelations about the life cycle of parasitic genetic elements

    PubMed Central

    Gogarten, J Peter; Hilario, Elena

    2006-01-01

    Self splicing introns and inteins that rely on a homing endonuclease for propagation are parasitic genetic elements. Their life-cycle and evolutionary fate has been described through the homing cycle. According to this model the homing endonuclease is selected for function only during the spreading phase of the parasite. This phase ends when the parasitic element is fixed in the population. Upon fixation the homing endonuclease is no longer under selection, and its activity is lost through random processes. Recent analyses of these parasitic elements with functional homing endonucleases suggest that this model in its most simple form is not always applicable. Apparently, functioning homing endonuclease can persist over long evolutionary times in populations and species that are thought to be asexual or nearly asexual. Here we review these recent findings and discuss their implications. Reasons for the long-term persistence of a functional homing endonuclease include: More recombination (sexual and as a result of gene transfer) than previously assumed for these organisms; complex population structures that prevent the element from being fixed; a balance between active spreading of the homing endonuclease and a decrease in fitness caused by the parasite in the host organism; or a function of the homing endonuclease that increases the fitness of the host organism and results in purifying selection for the homing endonuclease activity, even after fixation in a local population. In the future, more detailed studies of the population dynamics of the activity and regulation of homing endonucleases are needed to decide between these possibilities, and to determine their relative contributions to the long term survival of parasitic genes within a population. Two outstanding publications on the amoeba Naegleria group I intron (Wikmark et al. BMC Evol Biol 2006, 6:39) and the PRP8 inteins in ascomycetes (Butler et al.BMC Evol Biol 2006, 6:42) provide important stepping stones

  18. Selfish DNA: homing endonucleases find a home.

    PubMed

    Edgell, David R

    2009-02-10

    Self-splicing group I introns come in two flavours - those with a homing endonuclease to promote mobility of the intron, and those without an endonuclease. How homing endonucleases and self-splicing introns associate to form a composite selfish genetic element is a question of long-standing interest. Recent work has revealed that a shared characteristic of both introns and endonucleases, the targeting of conserved sequences, may provide the impetus for the evolution of composite mobile genetic elements.

  19. A model of EcoRII restriction endonuclease action: the active complex is most likely formed by one protein subunit and one DNA recognition site

    NASA Technical Reports Server (NTRS)

    Karpova, E. A.; Kubareva, E. A.; Shabarova, Z. A.

    1999-01-01

    To elucidate the mechanism of interaction of restriction endonuclease EcoRII with DNA, we studied by native gel electrophoresis the binding of this endonuclease to a set of synthetic DNA-duplexes containing the modified or canonical recognition sequence 5'-d(CCA/TGG)-3'. All binding substrate or substrate analogues tested could be divided into two major groups: (i) duplexes that, at the interaction with endonuclease EcoRII, form two types of stable complexes on native gel in the absence of Mg2+ cofactor; (ii) duplexes that form only one type of complex, observed both in the presence and absence of Mg2+. Unlike the latter, duplexes under the first group can be hydrolyzed by endonuclease. Data obtained suggest that the active complex is most likely formed by one protein subunit and one DNA recognition sequence. A model of EcoRII endonuclease action is presented.

  20. Cloning and Characterization of a Wheat Homologue of Apurinic/Apyrimidinic Endonuclease Ape1L

    PubMed Central

    Grin, Inga R.; Zharkov, Dmitry O.; Ishenko, Alexander A.; Tudek, Barbara; Bissenbaev, Amangeldy K.; Saparbaev, Murat

    2014-01-01

    Background Apurinic/apyrimidinic (AP) endonucleases are key DNA repair enzymes involved in the base excision repair (BER) pathway. In BER, an AP endonuclease cleaves DNA at AP sites and 3′-blocking moieties generated by DNA glycosylases and/or oxidative damage. A Triticum aestivum cDNA encoding for a putative homologue of ExoIII family AP endonucleases which includes E. coli Xth, human APE1 and Arabidopsis thaliana AtApe1L has been isolated and its protein product purified and characterized. Methodology/Principal Findings We report that the putative wheat AP endonuclease, referred here as TaApe1L, contains AP endonuclease, 3′-repair phosphodiesterase, 3′-phosphatase and 3′→5′ exonuclease activities. Surprisingly, in contrast to bacterial and human AP endonucleases, addition of Mg2+ and Ca2+ (5–10 mM) to the reaction mixture inhibited TaApe1L whereas the presence of Mn2+, Co2+ and Fe2+ cations (0.1–1.0 mM) strongly stimulated all its DNA repair activities. Optimization of the reaction conditions revealed that the wheat enzyme requires low divalent cation concentration (0.1 mM), mildly acidic pH (6–7), low ionic strength (20 mM KCl) and has a temperature optimum at around 20°C. The steady-state kinetic parameters of enzymatic reactions indicate that TaApe1L removes 3′-blocking sugar-phosphate and 3′-phosphate groups with good efficiency (k cat/K M = 630 and 485 μM−1·min−1, respectively) but possesses a very weak AP endonuclease activity as compared to the human homologue, APE1. Conclusions/Significance Taken together, these data establish the DNA substrate specificity of the wheat AP endonuclease and suggest its possible role in the repair of DNA damage generated by endogenous and environmental factors. PMID:24667595

  1. Endonuclease from Micrococcus luteus Which Has Activity Toward Ultraviolet-Irradiated Deoxyribonucleic Acid: Its Action on Transforming Deoxyribonucleic Acid

    PubMed Central

    Setlow, R. B.; Setlow, Jane K.; Carrier, W. L.

    1970-01-01

    An endonuclease purified from Micrococcus luteus makes single-strand breaks in ultraviolet (UV)-irradiated, native deoxyribonucleic acid (DNA). The purified endonuclease is able to reactivate UV-inactivated transforming DNA of Haemophilus influenzae, especially when the DNA is assayed on a UV-sensitive mutant of H. influenzae. After extensive endonuclease action, there is a loss of transforming DNA when assayed on both UV-sensitive and -resistant cells. The endonuclease does not affect unirradiated DNA. The results indicate that the endonuclease function is involved in the repair of biological damage resulting from UV irradiation and that the UV-sensitive mutant is deficient in this step. We interpret the data as indicating that the various steps in the repair of DNA must be well coordinated if repair is to be effective. PMID:4314478

  2. Dominant Mutations in S. cerevisiae PMS1 Identify the Mlh1-Pms1 Endonuclease Active Site and an Exonuclease 1-Independent Mismatch Repair Pathway

    PubMed Central

    Smith, Catherine E.; Mendillo, Marc L.; Bowen, Nikki; Hombauer, Hans; Campbell, Christopher S.; Desai, Arshad; Putnam, Christopher D.; Kolodner, Richard D.

    2013-01-01

    Lynch syndrome (hereditary nonpolypsis colorectal cancer or HNPCC) is a common cancer predisposition syndrome. Predisposition to cancer in this syndrome results from increased accumulation of mutations due to defective mismatch repair (MMR) caused by a mutation in one of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2/scPMS1. To better understand the function of Mlh1-Pms1 in MMR, we used Saccharomyces cerevisiae to identify six pms1 mutations (pms1-G683E, pms1-C817R, pms1-C848S, pms1-H850R, pms1-H703A and pms1-E707A) that were weakly dominant in wild-type cells, which surprisingly caused a strong MMR defect when present on low copy plasmids in an exo1Δ mutant. Molecular modeling showed these mutations caused amino acid substitutions in the metal coordination pocket of the Pms1 endonuclease active site and biochemical studies showed that they inactivated the endonuclease activity. This model of Mlh1-Pms1 suggested that the Mlh1-FERC motif contributes to the endonuclease active site. Consistent with this, the mlh1-E767stp mutation caused both MMR and endonuclease defects similar to those caused by the dominant pms1 mutations whereas mutations affecting the predicted metal coordinating residue Mlh1-C769 had no effect. These studies establish that the Mlh1-Pms1 endonuclease is required for MMR in a previously uncharacterized Exo1-independent MMR pathway. PMID:24204293

  3. Dominant mutations in S. cerevisiae PMS1 identify the Mlh1-Pms1 endonuclease active site and an exonuclease 1-independent mismatch repair pathway.

    PubMed

    Smith, Catherine E; Mendillo, Marc L; Bowen, Nikki; Hombauer, Hans; Campbell, Christopher S; Desai, Arshad; Putnam, Christopher D; Kolodner, Richard D

    2013-10-01

    Lynch syndrome (hereditary nonpolypsis colorectal cancer or HNPCC) is a common cancer predisposition syndrome. Predisposition to cancer in this syndrome results from increased accumulation of mutations due to defective mismatch repair (MMR) caused by a mutation in one of the mismatch repair genes MLH1, MSH2, MSH6 or PMS2/scPMS1. To better understand the function of Mlh1-Pms1 in MMR, we used Saccharomyces cerevisiae to identify six pms1 mutations (pms1-G683E, pms1-C817R, pms1-C848S, pms1-H850R, pms1-H703A and pms1-E707A) that were weakly dominant in wild-type cells, which surprisingly caused a strong MMR defect when present on low copy plasmids in an exo1Δ mutant. Molecular modeling showed these mutations caused amino acid substitutions in the metal coordination pocket of the Pms1 endonuclease active site and biochemical studies showed that they inactivated the endonuclease activity. This model of Mlh1-Pms1 suggested that the Mlh1-FERC motif contributes to the endonuclease active site. Consistent with this, the mlh1-E767stp mutation caused both MMR and endonuclease defects similar to those caused by the dominant pms1 mutations whereas mutations affecting the predicted metal coordinating residue Mlh1-C769 had no effect. These studies establish that the Mlh1-Pms1 endonuclease is required for MMR in a previously uncharacterized Exo1-independent MMR pathway.

  4. Analysis of class II (hydrolytic) and class I (beta-lyase) apurinic/apyrimidinic endonucleases with a synthetic DNA substrate.

    PubMed Central

    Levin, J D; Demple, B

    1990-01-01

    We have developed simple and sensitive assays that distinguish the main classes of apurinic/apyrimidinic (AP) endonucleases: Class I enzymes that cleave on the 3' side of AP sites by beta-elimination, and Class II enzymes that cleave by hydrolysis on the 5' side. The distinction of the two types depends on the use of a synthetic DNA polymer that contains AP sites with 5'-[32P]phosphate residues. Using this approach, we now show directly that Escherichia coli endonuclease IV and human AP endonuclease are Class II enzymes, as inferred previously on the basis of indirect assays. The assay method does not exhibit significant interference by nonspecific nucleases or primary amines, which allows the ready determination of different AP endonuclease activities in crude cell extracts. In this way, we show that virtually all of the Class II AP endonuclease activity in E. coli can be accounted for by two enzymes: exonuclease III and endonuclease IV. In the yeast Saccharomyces cerevisiae, the Class II AP endonuclease activity is totally dependent on a single enzyme, the Apn1 protein, but there are probably multiple Class I enzymes. The versatility and ease of our approach should be useful for characterizing this important class of DNA repair enzymes in diverse systems. PMID:1698278

  5. Synthesis, Biological Evaluation and Structure-Activity Relationships of a Novel Class of Apurinic/Apyrimidinic Endonuclease 1 Inhibitors

    PubMed Central

    Rai, Ganesha; Vyjayanti, Vaddadi N.; Dorjsuren, Dorjbal; Simeonov, Anton; Jadhav, Ajit; Wilson, David M.; Maloney, David J.

    2012-01-01

    APE1 is an essential protein that operates in the base excision repair (BER) pathway and is responsible for ≥95% of the total apurinic/apyrimidinic (AP) endonuclease activity in human cells. BER is a major pathway that copes with DNA damage induced by several anti-cancer agents, including ionizing radiation and temozolomide. Overexpression of APE1 and enhanced AP endonuclease activity has been linked to increased resistance of tumor cells to treatment with monofunctional alkylators, implicating inhibition of APE1 as a valid strategy for cancer therapy. We report herein the results of a focused medicinal chemistry effort around a novel APE1 inhibitor, N-(3-(benzo[d]thiazol-2-yl)-6-isopropyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridin-2-yl)acetamide (3). Compound 3 and related analogs exhibit single-digit µM activity against the purified APE1 enzyme, comparable activity in HeLa whole cell extract assays, and potentiate the cytotoxicity of the alkylating agents methylmethane sulfonate and temozolomide. Moreover, this class of compounds possesses a generally favorable in vitro ADME profile, along with good exposure levels in plasma and brain following intraperitoneal dosing (30 mg/kg body weight) in mice. PMID:22455312

  6. Single substitution in bacteriophage T4 RNase H alters the ratio between its exo- and endonuclease activities.

    PubMed

    Kholod, Natalia; Sivogrivov, Dmitry; Latypov, Oleg; Mayorov, Sergey; Kuznitsyn, Rafail; Kajava, Andrey V; Shlyapnikov, Mikhail; Granovsky, Igor

    2015-11-01

    The article describes substitutions in bacteriophage T4 RNase H which provide so called das-effect. Phage T4 DNA arrest suppression (das) mutations have been described to be capable of partially suppressing the phage DNA arrest phenotype caused by a dysfunction in genes 46 and/or 47 (also known as Mre11/Rad50 complex). Genetic mapping of das13 (one of the das mutations) has shown it to be in the region of the rnh gene encoding RNase H. Here we report that Das13 mutant of RNase H has substitutions of valine 43 and leucine 242 with isoleucines. To investigate the influence of these mutations on RNase H nuclease properties we have designed a novel in vitro assay that allows us to separate and quantify exo- or endonuclease activities of flap endonuclease. The nuclease assay in vitro showed that V43I substitution increased the ratio between exonuclease/endonuclease activities of RNase H whereas L242I substitution did not affect the nuclease activity of RNase H in vitro. However, both mutations were necessary for the full das effect in vivo. Molecular modelling of the nuclease structure suggests that V43I substitution may lead to disposition of H4 helix, responsible for the interaction with the first base pairs of 5'end of branched DNA. These structural changes may affect unwinding of the first base pairs of gapped or nicked DNA generating a short flap and therefore may stabilize the DNA-enzyme complex. L242I substitution did not affect the structure of RNase H and its role in providing das-effect remains unclear. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Phage T4 endonuclease SegD that is similar to group I intron endonucleases does not initiate homing of its own gene.

    PubMed

    Sokolov, Andrey S; Latypov, Oleg R; Kolosov, Peter M; Shlyapnikov, Michael G; Bezlepkina, Tamara A; Kholod, Natalia S; Kadyrov, Farid A; Granovsky, Igor E

    2018-02-01

    Homing endonucleases are a group of site-specific endonucleases that initiate homing, a nonreciprocal transfer of its own gene into a new allele lacking this gene. This work describes a novel phage T4 endonuclease, SegD, which is homologous to the GIY-YIG family of homing endonucleases. Like other T4 homing endonucleases SegD recognizes an extended, 16bp long, site, cleaves it asymmetrically to form 3'-protruding ends and digests both unmodified DNA and modified T-even phage DNA with similar efficiencies. Surprisingly, we revealed that SegD cleavage site was identical in the genomes of segD - and segD + phages. We found that segD gene was expressed during the T4 developmental cycle. Nevertheless, endonuclease SegD was not able to initiate homing of its own gene as well as genetic recombination between phages in its site inserted into the rII locus. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Problem-Solving Test: Restriction Endonuclease Mapping

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2011-01-01

    The term "restriction endonuclease mapping" covers a number of related techniques used to identify specific restriction enzyme recognition sites on small DNA molecules. A method for restriction endonuclease mapping of a 1,000-basepair (bp)-long DNA molecule is described in the fictitious experiment of this test. The most important fact needed to…

  9. 76 FR 50489 - Agency Information Collection Activities: Harbor Maintenance Fee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ... Activities: Harbor Maintenance Fee AGENCY: U.S. Customs and Border Protection, Department of Homeland... Security will be submitting the following information collection request to the Office of Management and Budget (OMB) for review and approval in accordance with the Paperwork Reduction Act: Harbor Maintenance...

  10. An electrochemiluminescence biosensor for endonuclease EcoRI detection.

    PubMed

    Li, Yingjie; Li, Yuqin; Wu, Yaoyu; Lu, Fushen; Chen, Yaowen; Gao, Wenhua

    2017-03-15

    Endonucleases cleavage of DNA plays an important role in biological and medicinal chemistry. This work was going to develop a reliable and sensitive electrochemiluminescent (ECL) biosensor for detecting endonucleases by using gold nanoparticles graphene composite (GNPs-graphene) as a signal amplifier. Firstly, the GNPs and graphene were simultaneously deposited on the glassy carbon electrode (GCE) by cyclic voltammetry. Then a stem DNA was anchored on the surface of GCE. And with a modifying DNA introduced into the electrode by DNA assembly, a strong ECL signal was obtained. After a DNA modified with ferrocene assembly to the stem DNA, the ECL signal had a sharp decrease due to the quench effect of ferrocene to and the biosensor comes into being a "off" state. With the effect of endonuclease, the ECL signal had a recovery because of the ferrocene being released and the biosensor formed a "on" state. Moreover, the recovery of ECL signal was related to the concentration of endonucleases. Combining specific defined DNA and endonuclease, this method has a potential to detect different endonucleases. In this work, we took the EcoRI as an example to identify the feasibility of ECL biosensor in applying in sensitive detection of endonucleases using a GNPs-graphene signal amplifier. Under optimal condition, the proposed biosensor obtained a low limit of detection (LOD) 5.6×10 -5 UmL -1 . And the stability, selectivity and reproducibility of the biosensor also were researched. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Evolution of divergent DNA recognition specificities in VDE homing endonucleases from two yeast species

    PubMed Central

    Posey, Karen L.; Koufopanou, Vassiliki; Burt, Austin; Gimble, Frederick S.

    2004-01-01

    Homing endonuclease genes (HEGs) are mobile DNA elements that are thought to confer no benefit to their host. They encode site-specific DNA endonucleases that perpetuate the element within a species population by homing and disseminate it between species by horizontal transfer. Several yeast species contain the VMA1 HEG that encodes the intein-associated VMA1-derived endonuclease (VDE). The evolutionary state of VDEs from 12 species was assessed by assaying their endonuclease activities. Only two enzymes are active, PI-ZbaI from Zygosaccharomyces bailii and PI-ScaI from Saccharomyces cariocanus. PI-ZbaI cleaves the Z.bailii recognition sequence significantly faster than the Saccharomyces cerevisiae site, which differs at six nucleotide positions. A mutational analysis indicates that PI-ZbaI cleaves the S.cerevisiae substrate poorly due to the absence of a contact that is analogous to one made in PI-SceI between Gln-55 and nucleotides +9/+10. PI-ZbaI cleaves the Z.bailii substrate primarily due to a single base-pair substitution (A/T+5 → T/A+5). Structural modeling of the PI-ZbaI/DNA complex suggests that Arg-331, which is absent in PI-SceI, contacts T/A+5, and the reduced activity observed in a PI-ZbaI R331A mutant provides evidence for this interaction. These data illustrate that homing endonucleases evolve altered specificity as they adapt to recognize alternative target sites. PMID:15280510

  12. Evolution of divergent DNA recognition specificities in VDE homing endonucleases from two yeast species.

    PubMed

    Posey, Karen L; Koufopanou, Vassiliki; Burt, Austin; Gimble, Frederick S

    2004-01-01

    Homing endonuclease genes (HEGs) are mobile DNA elements that are thought to confer no benefit to their host. They encode site-specific DNA endonucleases that perpetuate the element within a species population by homing and disseminate it between species by horizontal transfer. Several yeast species contain the VMA1 HEG that encodes the intein-associated VMA1-derived endonuclease (VDE). The evolutionary state of VDEs from 12 species was assessed by assaying their endonuclease activities. Only two enzymes are active, PI-ZbaI from Zygosaccharomyces bailii and PI-ScaI from Saccharomyces cariocanus. PI-ZbaI cleaves the Z.bailii recognition sequence significantly faster than the Saccharomyces cerevisiae site, which differs at six nucleotide positions. A mutational analysis indicates that PI-ZbaI cleaves the S.cerevisiae substrate poorly due to the absence of a contact that is analogous to one made in PI-SceI between Gln-55 and nucleotides +9/+10. PI-ZbaI cleaves the Z.bailii substrate primarily due to a single base-pair substitution (A/T+5 --> T/A+5). Structural modeling of the PI-ZbaI/DNA complex suggests that Arg-331, which is absent in PI-SceI, contacts T/A+5, and the reduced activity observed in a PI-ZbaI R331A mutant provides evidence for this interaction. These data illustrate that homing endonucleases evolve altered specificity as they adapt to recognize alternative target sites.

  13. Identification and characterization of influenza variants resistant to a viral endonuclease inhibitor

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

    Song, Min-Suk; Kumar, Gyanendra; Shadrick, William R.

    The influenza endonuclease is an essential subdomain of the viral RNA polymerase. It processes host pre-mRNAs to serve as primers for viral mRNA and is an attractive target for antiinfluenza drug discovery. Compound L-742,001 is a prototypical endonuclease inhibitor, and we found that repeated passaging of influenza virus in the presence of this drug did not lead to the development of resistant mutant strains. Reduced sensitivity to L-742,001 could only be induced by creating point mutations via a random mutagenesis strategy. Furthermore, these mutations mapped to the endonuclease active site where they can directly impact inhibitor binding. Engineered viruses containingmore » the mutations showed resistance to L-742,001 both in vitro and in vivo, with only a modest reduction in fitness. Introduction of the mutations into a second virus also increased its resistance to the inhibitor. When using the isolated wild-type and mutant endonuclease domains, we used kinetics, inhibitor binding and crystallography to characterize how the two most significant mutations elicit resistance to L-742,001. These studies lay the foundation for the development of a new class of influenza therapeutics with reduced potential for the development of clinical endonuclease inhibitor-resistant influenza strains.« less

  14. Identification and characterization of influenza variants resistant to a viral endonuclease inhibitor

    DOE PAGES

    Song, Min-Suk; Kumar, Gyanendra; Shadrick, William R.; ...

    2016-03-14

    The influenza endonuclease is an essential subdomain of the viral RNA polymerase. It processes host pre-mRNAs to serve as primers for viral mRNA and is an attractive target for antiinfluenza drug discovery. Compound L-742,001 is a prototypical endonuclease inhibitor, and we found that repeated passaging of influenza virus in the presence of this drug did not lead to the development of resistant mutant strains. Reduced sensitivity to L-742,001 could only be induced by creating point mutations via a random mutagenesis strategy. Furthermore, these mutations mapped to the endonuclease active site where they can directly impact inhibitor binding. Engineered viruses containingmore » the mutations showed resistance to L-742,001 both in vitro and in vivo, with only a modest reduction in fitness. Introduction of the mutations into a second virus also increased its resistance to the inhibitor. When using the isolated wild-type and mutant endonuclease domains, we used kinetics, inhibitor binding and crystallography to characterize how the two most significant mutations elicit resistance to L-742,001. These studies lay the foundation for the development of a new class of influenza therapeutics with reduced potential for the development of clinical endonuclease inhibitor-resistant influenza strains.« less

  15. The major human AP endonuclease (Ape1) is involved in the nucleotide incision repair pathway

    PubMed Central

    Gros, Laurent; Ishchenko, Alexander A.; Ide, Hiroshi; Elder, Rhoderick H.; Saparbaev, Murat K.

    2004-01-01

    In nucleotide incision repair (NIR), an endonuclease nicks oxidatively damaged DNA in a DNA glycosylase-independent manner, providing the correct ends for DNA synthesis coupled to the repair of the remaining 5′-dangling modified nucleotide. This mechanistic feature is distinct from DNA glycosylase-mediated base excision repair. Here we report that Ape1, the major apurinic/apyrimidinic endonuclease in human cells, is the damage- specific endonuclease involved in NIR. We show that Ape1 incises DNA containing 5,6-dihydro-2′-deoxyuridine, 5,6-dihydrothymidine, 5-hydroxy-2′-deoxyuridine, alpha-2′-deoxyadenosine and alpha-thymidine adducts, generating 3′-hydroxyl and 5′-phosphate termini. The kinetic constants indicate that Ape1-catalysed NIR activity is highly efficient. The substrate specificity and protein conformation of Ape1 is modulated by MgCl2 concentrations, thus providing conditions under which NIR becomes a major activity in cell-free extracts. While the N-terminal region of Ape1 is not required for AP endonuclease function, we show that it regulates the NIR activity. The physiological relevance of the mammalian NIR pathway is discussed. PMID:14704345

  16. Polycyclic aromatic hydrocarbons and trace elements bounded to airborne PM10 in the harbor of Volos, Greece: Implications for the impact of harbor activities

    NASA Astrophysics Data System (ADS)

    Manoli, E.; Chelioti-Chatzidimitriou, A.; Karageorgou, K.; Kouras, A.; Voutsa, D.; Samara, C.; Kampanos, I.

    2017-10-01

    Harbors are often characterized by high levels of air pollutants that are emitted from ship traffic and other harbor activities. In the present study, the concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) and trace elements (As, Cd, Ni, Pb, Cr, Mn, Zn, and Fe) bounded to the inhalable particulate matter PM10 were studied in the harbor of Volos, central Greece, during a 2-year period (2014-2015). Seasonal and daily variations were investigated. Moreover, total carcinogenic and mutagenic activities of PAHs were calculated. The effect of major wind sectors (sea, city, industrial, harbor) was estimated to assess the potential contribution of ship traffic and harbor activities, such as scrap metal handling operations. Results showed that the harbor sector (calm winds ≤ 0.5 m s-1) was associated with the highest concentrations of PM10. The harbor sector was also associated with relatively increased levels of trace elements (As, Fe, Cr, Mn, Ni), however the effect of this sector was lower than the corresponding effect of the industrial wind sector. The sea sector showed only a slight increase in B[a]Py and Σ12PAHs, whereas the highest increasing effect for PAHs and traffic-related elements, such as Pb and Zn, was evidenced for the city sector.

  17. Generation of genetically-engineered animals using engineered endonucleases.

    PubMed

    Lee, Jong Geol; Sung, Young Hoon; Baek, In-Jeoung

    2018-05-17

    The key to successful drug discovery and development is to find the most suitable animal model of human diseases for the preclinical studies. The recent emergence of engineered endonucleases is allowing for efficient and precise genome editing, which can be used to develop potentially useful animal models for human diseases. In particular, zinc finger nucleases, transcription activator-like effector nucleases, and the clustered regularly interspaced short palindromic repeat systems are revolutionizing the generation of diverse genetically-engineered experimental animals including mice, rats, rabbits, dogs, pigs, and even non-human primates that are commonly used for preclinical studies of the drug discovery. Here, we describe recent advances in engineered endonucleases and their application in various laboratory animals. We also discuss the importance of genome editing in animal models for more closely mimicking human diseases.

  18. Restoration of G1 chemo/radioresistance and double-strand-break repair proficiency by wild-type but not endonuclease-deficient Artemis.

    PubMed

    Mohapatra, Susovan; Kawahara, Misako; Khan, Imran S; Yannone, Steven M; Povirk, Lawrence F

    2011-08-01

    Deficiency in Artemis is associated with lack of V(D)J recombination, sensitivity to radiation and radiomimetic drugs, and failure to repair a subset of DNA double-strand breaks (DSBs). Artemis harbors an endonuclease activity that trims both 5'- and 3'-ends of DSBs. To examine whether endonucleolytic trimming of terminally blocked DSBs by Artemis is a biologically relevant function, Artemis-deficient fibroblasts were stably complemented with either wild-type Artemis or an endonuclease-deficient D165N mutant. Wild-type Artemis completely restored resistance to γ-rays, bleomycin and neocarzinostatin, and also restored DSB-repair proficiency in G0/G1 phase as measured by pulsed-field gel electrophoresis and repair focus resolution. In contrast, cells expressing the D165N mutant, even at very high levels, remained as chemo/radiosensitive and repair deficient as the parental cells, as evidenced by persistent γ-H2AX, 53BP1 and Mre11 foci that slowly increased in size and ultimately became juxtaposed with promyelocytic leukemia protein nuclear bodies. In normal fibroblasts, overexpression of wild-type Artemis increased radioresistance, while D165N overexpression conferred partial repair deficiency following high-dose radiation. Restoration of chemo/radioresistance by wild-type, but not D165N Artemis suggests that the lack of endonucleolytic trimming of DNA ends is the principal cause of sensitivity to double-strand cleaving agents in Artemis-deficient cells.

  19. Studies of the Interaction of Influenza Virus RNA Polymerase PAN with Endonuclease Inhibitors.

    PubMed

    Dong, Li-Hua; Cao, Xiao-Rong

    2018-06-01

    Influenza virus is a major causative agent of respiratory viral infections, and RNA polymerase catalyzes its replication and transcription activities in infected cell nuclei. Since it is highly conserved in all virus strains, RNA polymerase becomes a key target of anti-influenza virus agents. Although experimental studies have revealed the good inhibitory activity of endonuclease inhibitors to RNA polymerase, the mechanism is still unclear. In this study, the docking and molecular dynamics simulations have been performed to explore the interaction of three kinds of endonuclease inhibitors with the subunit (PA N ) of RNA polymerase. Our calculations indicate that all these endonuclease inhibitors can bind to the binding pocket of PA N , in which the electronegative oxygen atoms of the inhibitors form a chelated structure with the two Mn 2+ cations of the active center. The most important interaction between these inhibitors and PA N is electrostatic interaction. The electron density of the chelate oxygen atoms determines the magnitude of the electrostatic energy, and the chelated structure and orientation of inhibitors depend largely on the distance between the chelate oxygen atoms.

  20. Thermodynamics of DNA target site recognition by homing endonucleases

    PubMed Central

    Eastberg, Jennifer H.; Smith, Audrey McConnell; Zhao, Lei; Ashworth, Justin; Shen, Betty W.; Stoddard, Barry L.

    2007-01-01

    The thermodynamic profiles of target site recognition have been surveyed for homing endonucleases from various structural families. Similar to DNA-binding proteins that recognize shorter target sites, homing endonucleases display a narrow range of binding free energies and affinities, mediated by structural interactions that balance the magnitude of enthalpic and entropic forces. While the balance of ΔH and TΔS are not strongly correlated with the overall extent of DNA bending, unfavorable ΔHbinding is associated with unstacking of individual base steps in the target site. The effects of deleterious basepair substitutions in the optimal target sites of two LAGLIDADG homing endonucleases, and the subsequent effect of redesigning one of those endonucleases to accommodate that DNA sequence change, were also measured. The substitution of base-specific hydrogen bonds in a wild-type endonuclease/DNA complex with hydrophobic van der Waals contacts in a redesigned complex reduced the ability to discriminate between sites, due to nonspecific ΔSbinding. PMID:17947319

  1. Fragment-Based Identification of Influenza Endonuclease Inhibitors

    PubMed Central

    2016-01-01

    The influenza virus is responsible for millions of cases of severe illness annually. Yearly variance in the effectiveness of vaccination, coupled with emerging drug resistance, necessitates the development of new drugs to treat influenza infections. One attractive target is the RNA-dependent RNA polymerase PA subunit. Herein we report the development of inhibitors of influenza PA endonuclease derived from lead compounds identified from a metal-binding pharmacophore (MBP) library screen. Pyromeconic acid and derivatives thereof were found to be potent inhibitors of endonuclease. Guided by modeling and previously reported structural data, several sublibraries of molecules were elaborated from the MBP hits. Structure–activity relationships were established, and more potent molecules were designed and synthesized using fragment growth and fragment merging strategies. This approach ultimately resulted in the development of a lead compound with an IC50 value of 14 nM, which displayed an EC50 value of 2.1 μM against H1N1 influenza virus in MDCK cells. PMID:27291165

  2. The metabolic enhancer piracetam attenuates mitochondrion-specific endonuclease G translocation and oxidative DNA fragmentation.

    PubMed

    Gupta, Sonam; Verma, Dinesh Kumar; Biswas, Joyshree; Rama Raju, K Siva; Joshi, Neeraj; Wahajuddin; Singh, Sarika

    2014-08-01

    This study was performed to investigate the involvement of mitochondrion-specific endonuclease G in piracetam (P)-induced protective mechanisms. Studies have shown the antiapoptotic effects of piracetam but the mechanism of action of piracetam is still an enigma. To assess the involvement of endonuclease G in piracetam-induced protective effects, astrocyte glial cells were treated with lipopolysaccharide (LPS) and piracetam. LPS treatment caused significantly decreased viability, mitochondrial activity, oxidative stress, chromatin condensation, and DNA fragmentation, which were attenuated by piracetam cotreatment. Cotreatment of astrocytes with piracetam showed its significantly time-dependent absorption as observed with high-performance liquid chromatography. Astrocytes treated with piracetam alone showed enhanced mitochondrial membrane potential (MMP) in comparison to control astrocytes. However, in LPS-treated cells no significant alteration in MMP was observed in comparison to control cells. Protein and mRNA levels of the terminal executor of the caspase-mediated pathway, caspase-3, were not altered significantly in LPS or LPS + piracetam-treated astrocytes, whereas endonuclease G was significantly translocated to the nucleus in LPS-treated astrocytes. Piracetam cotreatment attenuated the LPS-induced endonuclease G translocation. In conclusion this study indicates that LPS treatment of astrocytes caused decreased viability, oxidative stress, mitochondrial dysfunction, chromatin condensation, DNA damage, and translocation of endonuclease G to the nucleus, which was inhibited by piracetam cotreatment, confirming that the mitochondrion-specific endonuclease G is one of the factors involved in piracetam-induced protective mechanisms. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Identification of potential influenza virus endonuclease inhibitors through virtual screening based on the 3D-QSAR model.

    PubMed

    Kim, J; Lee, C; Chong, Y

    2009-01-01

    Influenza endonucleases have appeared as an attractive target of antiviral therapy for influenza infection. With the purpose of designing a novel antiviral agent with enhanced biological activities against influenza endonuclease, a three-dimensional quantitative structure-activity relationships (3D-QSAR) model was generated based on 34 influenza endonuclease inhibitors. The comparative molecular similarity index analysis (CoMSIA) with a steric, electrostatic and hydrophobic (SEH) model showed the best correlative and predictive capability (q(2) = 0.763, r(2) = 0.969 and F = 174.785), which provided a pharmacophore composed of the electronegative moiety as well as the bulky hydrophobic group. The CoMSIA model was used as a pharmacophore query in the UNITY search of the ChemDiv compound library to give virtual active compounds. The 3D-QSAR model was then used to predict the activity of the selected compounds, which identified three compounds as the most likely inhibitor candidates.

  4. Alternative Nucleophilic Substrates for the Endonuclease Activities of Human Immunodeficiency Virus Type 1 Integrase

    PubMed Central

    Ealy, Julie B.; Sudol, Malgorzata; Krzeminski, Jacek; Amin, Shantu; Katzman, Michael

    2012-01-01

    Retroviral integrase can use water or some small alcohols as the attacking nucleophile to nick DNA. To characterize the range of compounds that human immunodeficiency virus type 1 integrase can accommodate for its endonuclease activities, we tested 45 potential electron donors (having varied size and number or spacing of nucleophilic groups) as substrates during site-specific nicking at viral DNA ends and during nonspecific nicking reactions. We found that integrase used 22 of the 45 compounds to nick DNA, but not all active compounds were used for both activities. In particular, 13 compounds were used for site-specific and nonspecific nicking, 5 only for site-specific nicking, and 4 only for nonspecific nicking; 23 other compounds were not used for either activity. Thus, integrase can accommodate a large number of nucleophilic substrates but has selective requirements for its different activities, underscoring its dynamic properties and providing new information for modeling and understanding integrase. PMID:22910593

  5. Mutations altering the cleavage specificity of a homing endonuclease

    PubMed Central

    Seligman, Lenny M.; Chisholm, Karen M.; Chevalier, Brett S.; Chadsey, Meggen S.; Edwards, Samuel T.; Savage, Jeremiah H.; Veillet, Adeline L.

    2002-01-01

    The homing endonuclease I-CreI recognizes and cleaves a particular 22 bp DNA sequence. The crystal structure of I-CreI bound to homing site DNA has previously been determined, leading to a number of predictions about specific protein–DNA contacts. We test these predictions by analyzing a set of endonuclease mutants and a complementary set of homing site mutants. We find evidence that all structurally predicted I-CreI/DNA contacts contribute to DNA recognition and show that these contacts differ greatly in terms of their relative importance. We also describe the isolation of a collection of altered specificity I-CreI derivatives. The in vitro DNA-binding and cleavage properties of two such endonucleases demonstrate that our genetic approach is effective in identifying homing endonucleases that recognize and cleave novel target sequences. PMID:12202772

  6. Linear nicking endonuclease-mediated strand-displacement DNA amplification.

    PubMed

    Joneja, Aric; Huang, Xiaohua

    2011-07-01

    We describe a method for linear isothermal DNA amplification using nicking endonuclease-mediated strand displacement by a DNA polymerase. The nicking of one strand of a DNA target by the endonuclease produces a primer for the polymerase to initiate synthesis. As the polymerization proceeds, the downstream strand is displaced into a single-stranded form while the nicking site is also regenerated. The combined continuous repetitive action of nicking by the endonuclease and strand-displacement synthesis by the polymerase results in linear amplification of one strand of the DNA molecule. We demonstrate that DNA templates up to 5000 nucleotides can be linearly amplified using a nicking endonuclease with 7-bp recognition sequence and Sequenase version 2.0 in the presence of single-stranded DNA binding proteins. We also show that a mixture of three templates of 500, 1000, and 5000 nucleotides in length is linearly amplified with the original molar ratios of the templates preserved. Moreover, we demonstrate that a complex library of hydrodynamically sheared genomic DNA from bacteriophage lambda can be amplified linearly. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Linear nicking endonuclease-mediated strand displacement DNA amplification

    PubMed Central

    Joneja, Aric; Huang, Xiaohua

    2011-01-01

    We describe a method for linear isothermal DNA amplification using nicking endonuclease-mediated strand displacement by a DNA polymerase. The nicking of one strand of a DNA target by the endonuclease produces a primer for the polymerase to initiate synthesis. As the polymerization proceeds, the downstream strand is displaced into a single-stranded form while the nicking site is also regenerated. The combined continuous repetitive action of nicking by the endonuclease and strand displacement synthesis by the polymerase results in linear amplification of one strand of the DNA molecule. We demonstrate that DNA templates up to five thousand nucleotides can be linearly amplified using a nicking endonuclease with seven base-pair recognition sequence and Sequenase version 2.0 in the presence of single-stranded DNA binding proteins. We also show that a mixture of three templates of 500, 1000, and 5000 nucleotides in length are linearly amplified with the original molar ratios of the templates preserved. Moreover, we demonstrate that a complex library of hydrodynamically sheared genomic DNA from bacteriophage lambda can be amplified linearly. PMID:21342654

  8. Endonuclease-independent LINE-1 retrotransposition at mammalian telomeres.

    PubMed

    Morrish, Tammy A; Garcia-Perez, José Luis; Stamato, Thomas D; Taccioli, Guillermo E; Sekiguchi, JoAnn; Moran, John V

    2007-03-08

    Long interspersed element-1 (LINE-1 or L1) elements are abundant, non-long-terminal-repeat (non-LTR) retrotransposons that comprise approximately 17% of human DNA. The average human genome contains approximately 80-100 retrotransposition-competent L1s (ref. 2), and they mobilize by a process that uses both the L1 endonuclease and reverse transcriptase, termed target-site primed reverse transcription. We have previously reported an efficient, endonuclease-independent L1 retrotransposition pathway (EN(i)) in certain Chinese hamster ovary (CHO) cell lines that are defective in the non-homologous end-joining (NHEJ) pathway of DNA double-strand-break repair. Here we have characterized EN(i) retrotransposition events generated in V3 CHO cells, which are deficient in DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity and have both dysfunctional telomeres and an NHEJ defect. Notably, approximately 30% of EN(i) retrotransposition events insert in an orientation-specific manner adjacent to a perfect telomere repeat (5'-TTAGGG-3'). Similar insertions were not detected among EN(i) retrotransposition events generated in controls or in XR-1 CHO cells deficient for XRCC4, an NHEJ factor that is required for DNA ligation but has no known function in telomere maintenance. Furthermore, transient expression of a dominant-negative allele of human TRF2 (also called TERF2) in XRCC4-deficient XR-1 cells, which disrupts telomere capping, enables telomere-associated EN(i) retrotransposition events. These data indicate that L1s containing a disabled endonuclease can use dysfunctional telomeres as an integration substrate. The findings highlight similarities between the mechanism of EN(i) retrotransposition and the action of telomerase, because both processes can use a 3' OH for priming reverse transcription at either internal DNA lesions or chromosome ends. Thus, we propose that EN(i) retrotransposition is an ancestral mechanism of RNA-mediated DNA repair associated with non

  9. A domain in human EXOG converts apoptotic endonuclease to DNA-repair exonuclease

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

    Szymanski, Michal R.; Yu, Wangsheng; Gmyrek, Aleksandra M.

    Human EXOG (hEXOG) is a 5'-exonuclease that is crucial for mitochondrial DNA repair; the enzyme belongs to a nonspecific nuclease family that includes the apoptotic endonuclease EndoG. Here we report biochemical and structural studies of hEXOG, including structures in its apo form and in a complex with DNA at 1.81 and 1.85 Å resolution, respectively. A Wing domain, absent in other ββα-Me members, suppresses endonuclease activity, but confers on hEXOG a strong 5'-dsDNA exonuclease activity that precisely excises a dinucleotide using an intrinsic ‘tape-measure’. The symmetrical apo hEXOG homodimer becomes asymmetrical upon binding to DNA, providing a structural basis formore » how substrate DNA bound to one active site allosterically regulates the activity of the other. These properties of hEXOG suggest a pathway for mitochondrial BER that provides an optimal substrate for subsequent gap-filling synthesis by DNA polymerase γ.« less

  10. Creation of a type IIS restriction endonuclease with a long recognition sequence

    PubMed Central

    Lippow, Shaun M.; Aha, Patti M.; Parker, Matthew H.; Blake, William J.; Baynes, Brian M.; Lipovšek, Daša

    2009-01-01

    Type IIS restriction endonucleases cleave DNA outside their recognition sequences, and are therefore particularly useful in the assembly of DNA from smaller fragments. A limitation of type IIS restriction endonucleases in assembly of long DNA sequences is the relative abundance of their target sites. To facilitate ligation-based assembly of extremely long pieces of DNA, we have engineered a new type IIS restriction endonuclease that combines the specificity of the homing endonuclease I-SceI with the type IIS cleavage pattern of FokI. We linked a non-cleaving mutant of I-SceI, which conveys to the chimeric enzyme its specificity for an 18-bp DNA sequence, to the catalytic domain of FokI, which cuts DNA at a defined site outside the target site. Whereas previously described chimeric endonucleases do not produce type IIS-like precise DNA overhangs suitable for ligation, our chimeric endonuclease cleaves double-stranded DNA exactly 2 and 6 nt from the target site to generate homogeneous, 5′, four-base overhangs, which can be ligated with 90% fidelity. We anticipate that these enzymes will be particularly useful in manipulation of DNA fragments larger than a thousand bases, which are very likely to contain target sites for all natural type IIS restriction endonucleases. PMID:19304757

  11. A novel label-free fluorescence strategy for methyltransferase activity assay based on dsDNA-templated copper nanoparticles coupled with an endonuclease-assisted signal transduction system.

    PubMed

    Lai, Q Q; Liu, M D; Gu, C C; Nie, H G; Xu, X J; Li, Z H; Yang, Z; Huang, S M

    2016-02-21

    Evaluating DNA methyltransferase (MTase) activity has received considerable attention due to its significance in the fields of early cancer clinical diagnostics and drug discovery. Herein, we proposed a novel label-free fluorescence method for MTase activity assay by coupling double-stranded DNA (dsDNA)-templated copper nanoparticles (CuNPs) with an endonuclease-assisted signal transduction system. In this strategy, dsDNA molecules were first methylated by DNA adenine methylation (Dam) MTase and then cleaved by the methylation-sensitive restriction endonuclease DpnI. The cleaved DNA fragments could not act as efficient templates for the formation of fluorescent CuNPs and thus no fluorescence signal was produced. Under optimized experimental conditions, the developed strategy exhibited a sensitive fluorescence response to Dam MTase activity. This strategy was also demonstrated to provide an excellent platform to the inhibitor screening for Dam MTase. These results demonstrated the great potential for the practical applications of the proposed strategy for Dam MTase activity assay.

  12. 78 FR 19632 - Special Local Regulations; St. Thomas Carnival Watersport Activities, Charlotte Amalie Harbor; St...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-02

    ...-AA08 Special Local Regulations; St. Thomas Carnival Watersport Activities, Charlotte Amalie Harbor; St... proposes to establish a special local regulation on the waters of Charlotte Amalie Harbor in St Thomas, USVI during the St. Thomas Carnival Watersport Activities, a high speed boat race. The event is...

  13. The DNA repair endonuclease Mus81 facilitates fast DNA replication in the absence of exogenous damage

    PubMed Central

    Fu, Haiqing; Martin, Melvenia M.; Regairaz, Marie; Huang, Liang; You, Yang; Lin, Chi-Mei; Ryan, Michael; Kim, RyangGuk; Shimura, Tsutomu; Pommier, Yves; Aladjem, Mirit I.

    2015-01-01

    The Mus81 endonuclease resolves recombination intermediates and mediates cellular responses to exogenous replicative stress. Here, we show that Mus81 also regulates the rate of DNA replication during normal growth by promoting replication fork progression while reducing the frequency of replication initiation events. In the absence of Mus81 endonuclease activity, DNA synthesis is slowed and replication initiation events are more frequent. In addition, Mus81 deficient cells fail to recover from exposure to low doses of replication inhibitors and cell viability is dependent on the XPF endonuclease. Despite an increase in replication initiation frequency, cells lacking Mus81 use the same pool of replication origins as Mus81-expressing cells. Therefore, decelerated DNA replication in Mus81 deficient cells does not initiate from cryptic or latent origins not used during normal growth. These results indicate that Mus81 plays a key role in determining the rate of DNA replication without activating a novel group of replication origins. PMID:25879486

  14. An AP Endonuclease Functions in Active DNA Demethylation and Gene Imprinting in Arabidopsis

    PubMed Central

    Li, Yan; Córdoba-Cañero, Dolores; Qian, Weiqiang; Zhu, Xiaohong; Tang, Kai; Zhang, Huiming; Ariza, Rafael R.; Roldán-Arjona, Teresa; Zhu, Jian-Kang

    2015-01-01

    Active DNA demethylation in plants occurs through base excision repair, beginning with removal of methylated cytosine by the ROS1/DME subfamily of 5-methylcytosine DNA glycosylases. Active DNA demethylation in animals requires the DNA glycosylase TDG or MBD4, which functions after oxidation or deamination of 5-methylcytosine, respectively. However, little is known about the steps following DNA glycosylase action in the active DNA demethylation pathways in plants and animals. We show here that the Arabidopsis APE1L protein has apurinic/apyrimidinic endonuclease activities and functions downstream of ROS1 and DME. APE1L and ROS1 interact in vitro and co-localize in vivo. Whole genome bisulfite sequencing of ape1l mutant plants revealed widespread alterations in DNA methylation. We show that the ape1l/zdp double mutant displays embryonic lethality. Notably, the ape1l+/−zdp−/− mutant shows a maternal-effect lethality phenotype. APE1L and the DNA phosphatase ZDP are required for FWA and MEA gene imprinting in the endosperm and are important for seed development. Thus, APE1L is a new component of the active DNA demethylation pathway and, together with ZDP, regulates gene imprinting in Arabidopsis. PMID:25569774

  15. Magnesium-dependent RNA binding to the PA endonuclease domain of the avian influenza polymerase.

    PubMed

    Xiao, Shiyan; Klein, Michael L; LeBard, David N; Levine, Benjamin G; Liang, Haojun; MacDermaid, Christopher M; Alfonso-Prieto, Mercedes

    2014-01-30

    Influenza A viruses are highly pathogenic and pose an unpredictable public health danger to humans. An attractive target for developing new antiviral drugs is the PA N-terminal domain (PAN) of influenza polymerase, which is responsible for the endonuclease activity and essential for viral replication. Recently, the crystal structures of the holo form of PAN as well as PAN bound to different inhibitors have been reported, but the potency and selectivity of these inhibitors still need to be improved. New drug design can be guided by a better understanding of the endonuclease activity of PAN. However, this requires the structure of PAN in complex with the host mRNA, which has not been determined yet. In particular, divalent metal ions are known to be essential for RNA cleavage, but it is not clear whether there is either one or two Mg ions in the PAN active site. In the present work, we have modeled the complex of the PAN endonuclease domain with the host mRNA in the presence of either one or two Mg(2+) by using all-atom molecular dynamics. These simulations identify crucial interactions between the enzyme and the nucleic acid. Moreover, they validate a previous hypothesis that a second metal ion binds in the presence of the RNA substrate and therefore support a two-metal ion mechanism, in which K134 decreases the pKa of the nucleophilic water. Nevertheless, at low Mg concentrations an alternative, one-metal ion mechanism is possible, with K137 as the catalytic lysine and H41 as the general base, rationalizing previous unexpected mutagenesis results. The RNA-enzyme interactions determined here could likely be used to design more specific endonuclease inhibitors to fight influenza viral infections.

  16. Biochemical characterization of a thermostable endonuclease V from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5.

    PubMed

    Wang, Yuxiao; Zhang, Likui; Zhu, Xinyuan; Li, Yuting; Shi, Haoqiang; Oger, Philippe; Yang, Zhihui

    2018-05-22

    Endonuclease V (Endo V) is an important enzyme for repairing deoxyinosine in DNA. While bacterial and eukaryotic endo Vs have been well studied, knowledge of archaeal endo Vs is limited. Here, we first presented biochemical characterization of a thermostable endonuclease V from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 (Tba endo V). The recombinant enzyme possessed optimal endonuclease activity for cleaving deoxyinosine-containing DNA at 70-90 °C. Furthermore, Tba endo V can withstand 100 °C for 120 min without significant loss of its activity, suggesting the enzyme is thermostable. Tba endo V exhibited varying cleavage efficiencies at various pH levels from 6.0 to 11.0, among which an optimal pH for the enzyme was 8.0-9.0. In addition, a divalent metal ion was required for the enzyme to cleave DNA. Mn 2+ and Mg 2+ were optimal ions for the enzyme's activity whereas Ca 2+ , Zn 2+ and Co 2+ inhibited the enzyme activity. Moreover, the enzyme activity was suppressed by high NaCl concentration. Tba endo V bound to all DNA substrates; however, the enzyme exhibited a higher affinity for binding to deoxyinosine-containing DNA than normal DNA. Our work provides valuable information for revealing the role of Tba endo V in the base excision repair pathway for deoxyinosine repair in Thermococcus. Copyright © 2018. Published by Elsevier B.V.

  17. Specific action of T4 endonuclease V on damaged DNA in xeroderma pigmentosum cells in vivo. [UV radiation

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

    Tanaka, K.; Hayakawa, H.; Sekiguchi, M.

    1977-07-01

    The specific action of T4 endonuclease V on damaged DNA in xeroderma pigmentosum cells was examined using an in vivo assay system with hemagglutinating virus of Japan (Sendai virus) inactivated by uv light. A clear dose response was observed between the level of uv-induced unscheduled DNA synthesis of xeroderma pigmentosum cells and the amount of T4 endonuclease V activity added. The T4 enzyme was unstable in human cells, and its half-life was 3 hr. Fractions derived from an extract of Escherichia coli infected with T4v/sub 1/, a mutant defective in the endonuclease V gene, showed no ability to restore themore » uv-induced unscheduled DNA synthesis of xeroderma pigmentosum cells. However, fractions derived from an extract of T4D-infected E. coli with endonuclease V activity were effective. The T4 enzyme was effective in xeroderma pigmentosum cells on DNA damaged by uv light but not in cells damaged by 4-nitroquinoline 1-oxide. The results of these experiments show that the T4 enzyme has a specific action on human cell DNA in vivo. Treatment with the T4 enzyme increased the survival of group A xeroderma pigmentosum cells after uv irradiation.« less

  18. Endonuclease G promotes mitochondrial genome cleavage and replication

    PubMed Central

    Wiehe, Rahel Stefanie; Gole, Boris; Chatre, Laurent; Walther, Paul; Calzia, Enrico; Ricchetti, Miria; Wiesmüller, Lisa

    2018-01-01

    Endonuclease G (EndoG) is a nuclear-encoded endonuclease, mostly localised in mitochondria. In the nucleus EndoG participates in site-specific cleavage during replication stress and genome-wide DNA degradation during apoptosis. However, the impact of EndoG on mitochondrial DNA (mtDNA) metabolism is poorly understood. Here, we investigated whether EndoG is involved in the regulation of mtDNA replication and removal of aberrant copies. We applied the single-cell mitochondrial Transcription and Replication Imaging Protocol (mTRIP) and PCR-based strategies on human cells after knockdown/knockout and re-expression of EndoG. Our analysis revealed that EndoG stimulates both mtDNA replication initiation and mtDNA depletion, the two events being interlinked and dependent on EndoG's nuclease activity. Stimulation of mtDNA replication by EndoG was independent of 7S DNA processing at the replication origin. Importantly, both mtDNA-directed activities of EndoG were promoted by oxidative stress. Inhibition of base excision repair (BER) that repairs oxidative stress-induced DNA damage unveiled a pronounced effect of EndoG on mtDNA removal, reminiscent of recently discovered links between EndoG and BER in the nucleus. Altogether with the downstream effects on mitochondrial transcription, protein expression, redox status and morphology, this study demonstrates that removal of damaged mtDNA by EndoG and compensatory replication play a critical role in mitochondria homeostasis. PMID:29719607

  19. Activation of apurinic/apyrimidinic endonuclease in human cells by reactive oxygen species and its correlation with their adaptive response to genotoxicity of free radicals

    PubMed Central

    Ramana, Chilakamarti V.; Boldogh, Istvan; Izumi, Tadahide; Mitra, Sankar

    1998-01-01

    Apurinic/apyrimidinic (AP) endonuclease (APE; EC 4.2.99.18) plays a central role in repair of DNA damage due to reactive oxygen species (ROS) because its DNA 3′-phosphoesterase activity removes 3′ blocking groups in DNA that are generated by DNA glycosylase/AP-lyases during removal of oxidized bases and by direct ROS reaction with DNA. The major human APE (APE-1) gene is activated selectively by sublethal levels of a variety of ROS and ROS generators, including ionizing radiation, but not by other genotoxicants—e.g., UV light and alkylating agents. Increased expression of APE mRNA and protein was observed both in the HeLa S3 tumor line and in WI 38 primary fibroblasts, and it was accompanied by translocation of the endonuclease to the nucleus. ROS-treated cells showed a significant increase in resistance to the cytotoxicity of such ROS generators as H2O2 and bleomycin, but not to UV light. This “adaptive response” appears to result from enhanced repair of cytotoxic DNA lesions due to an increased activity of APE-1, which may be limiting in the base excision repair process for ROS-induced toxic lesions. PMID:9560228

  20. SLX4 Assembles a Telomere Maintenance Toolkit by Bridging Multiple Endonucleases with Telomeres

    PubMed Central

    Wan, Bingbing; Yin, Jinhu; Horvath, Kent; Sarkar, Jaya; Chen, Yong; Wu, Jian; Wan, Ke; Lu, Jian; Gu, Peili; Yu, Eun Young; Lue, Neal F.; Chang, Sandy

    2014-01-01

    Summary SLX4 interacts with several endonucleases to resolve structural barriers in DNA metabolism. SLX4 also interacts with telomeric protein TRF2 in human cells. The molecular mechanism of these interactions at telomeres remains unknown. Here, we report the crystal structure of the TRF2-binding motif of SLX4 (SLX4TBM) in complex with the TRFH domain of TRF2 (TRF2TRFH) and map the interactions of SLX4 with endonucleases SLX1, XPF, and MUS81. TRF2 recognizes a unique HxLxP motif on SLX4 via the peptide-binding site in its TRFH domain. Telomeric localization of SLX4 and associated nucleases depend on the SLX4-endonuclease and SLX4-TRF2 interactions and the protein levels of SLX4 and TRF2. SLX4 assembles an endonuclease toolkit that negatively regulates telomere length via SLX1-catalyzed nucleolytic resolution of telomere DNA structures. We propose that the SLX4-TRF2 complex serves as a double-layer scaffold bridging multiple endonucleases with telomeres for recombination-based telomere maintenance. PMID:24012755

  1. Final Environmental Impact Statement. Ontonagon Harbor Operation and Maintenance Activities. Ontonagon County, Michigan.

    DTIC Science & Technology

    1975-08-01

    Paul, Minnesota 55101 August 1975 ,.’U * - S • S S S S S • S U U FIN"L ENVIRONMENTAL IMPACT STATEMENT OPERATION AND MAINTENANCE ACTIVITIES ONTONAGON...HARBOR, MICHIGAN LAKE SUPERIOR Responsible Office: St. Paul District, Corps of Engineers, 1135 U.S. Post Office and Custom House, St. Paul, Minnesota ... mining is present at White Pine, 12 air miles southwest of Ontonagon Harbor. 6 2.130 Topography. - The area’s topography is directly related to the

  2. Characterization of Sulfolobus islandicus rod-shaped virus 2 gp19, a single-strand specific endonuclease.

    PubMed

    Gardner, Andrew F; Prangishvili, David; Jack, William E

    2011-09-01

    The hyperthermophilic Sulfolobus islandicus rod-shaped virus 2 (SIRV2) encodes a 25-kDa protein (SIRV2gp19) annotated as a hypothetical protein with sequence homology to the RecB nuclease superfamily. Even though SIRV2gp19 homologs are conserved throughout the rudivirus family and presumably play a role in the viral life cycle, SIRV2gp19 has not been functionally characterized. To define the minimal requirements for activity, SIRV2gp19 was purified and tested under varying conditions. SIRV2gp19 is a single-strand specific endonuclease that requires Mg(2+) for activity and is inactive on double-stranded DNA. A conserved aspartic acid in RecB nuclease superfamily Motif II (D89) is also essential for SIRV2gp19 activity and mutation to alanine (D89A) abolishes activity. Therefore, the SIRV2gp19 cleavage mechanism is similar to previously described RecB nucleases. Finally, SIRV2gp19 single-stranded DNA endonuclease activity could play a role in host chromosome degradation during SIRV2 lytic infection.

  3. A Sequence-Specific Nicking Endonuclease from Streptomyces: Purification, Physical and Catalytic Properties

    PubMed Central

    Somyoonsap, Peechapack; Kitpreechavanich, Vichein

    2013-01-01

    A sequence-specific nicking endonuclease from Streptomyces designated as DC13 was purified to near homogeneity. Starting with 30 grams of wet cells, the enzyme was purified by ammonium sulfate fractionation, DEAE cellulose, and phenyl-Sepharose chromatography. The purified protein had a specific activity 1000 units/mg and migrated on SDS-PAGE gel with an estimated molecular weight of 71 kDa. Determination of subunit composition by gel filtration chromatography indicated that the native enzyme is a monomer. When incubated with different DNA substrates including pBluescript II KS, pUC118, pET-15b, and pET-26b, the enzyme converted these supercoiled plasmids to a mixture of open circular and linear DNA products, with the open circular DNA as the major cleavage product. Analysis of the kinetic of DNA cleavage showed that the enzyme appeared to cleave super-coiled plasmid in two distinct steps: a rapid cleavage of super-coiled plasmid to an open circular DNA followed a much slower step to linear DNA. The DNA cleavage reaction of the enzyme required Mg2+ as a cofactor. Based on the monomeric nature of the enzyme, the kinetics of DNA cleavage exhibited by the enzyme, and cofactor requirement, it is suggested here that the purified enzyme is a sequence-specific nicking endonuclease that is similar to type IIS restriction endonuclease. PMID:25937959

  4. Evolutionary maintenance of selfish homing endonuclease genes in the absence of horizontal transfer.

    PubMed

    Yahara, Koji; Fukuyo, Masaki; Sasaki, Akira; Kobayashi, Ichizo

    2009-11-03

    Homing endonuclease genes are "selfish" mobile genetic elements whose endonuclease promotes the spread of its own gene by creating a break at a specific target site and using the host machinery to repair the break by copying and inserting the gene at this site. Horizontal transfer across the boundary of a species or population within which mating takes place has been thought to be necessary for their evolutionary persistence. This is based on the assumption that they will become fixed in a host population, where opportunities of homing will disappear, and become susceptible to degeneration. To test this hypothesis, we modeled behavior of a homing endonuclease gene that moves during meiosis through double-strand break repair. We mathematically explored conditions for persistence of the homing endonuclease gene and elucidated their parameter dependence as phase diagrams. We found that, if the cost of the pseudogene is lower than that of the homing endonuclease gene, the 2 forms can persist in a population through autonomous periodic oscillation. If the cost of the pseudogene is higher, 2 types of dynamics appear that enable evolutionary persistence: bistability dependent on initial frequency or fixation irrespective of initial frequency. The prediction of long persistence in the absence of horizontal transfer was confirmed by stochastic simulations in finite populations. The average time to extinction of the endonuclease gene was found to be thousands of meiotic generations or more based on realistic parameter values. These results provide a solid theoretical basis for an understanding of these and other extremely selfish elements.

  5. Evolutionary maintenance of selfish homing endonuclease genes in the absence of horizontal transfer

    PubMed Central

    Yahara, Koji; Fukuyo, Masaki; Sasaki, Akira; Kobayashi, Ichizo

    2009-01-01

    Homing endonuclease genes are “selfish” mobile genetic elements whose endonuclease promotes the spread of its own gene by creating a break at a specific target site and using the host machinery to repair the break by copying and inserting the gene at this site. Horizontal transfer across the boundary of a species or population within which mating takes place has been thought to be necessary for their evolutionary persistence. This is based on the assumption that they will become fixed in a host population, where opportunities of homing will disappear, and become susceptible to degeneration. To test this hypothesis, we modeled behavior of a homing endonuclease gene that moves during meiosis through double-strand break repair. We mathematically explored conditions for persistence of the homing endonuclease gene and elucidated their parameter dependence as phase diagrams. We found that, if the cost of the pseudogene is lower than that of the homing endonuclease gene, the 2 forms can persist in a population through autonomous periodic oscillation. If the cost of the pseudogene is higher, 2 types of dynamics appear that enable evolutionary persistence: bistability dependent on initial frequency or fixation irrespective of initial frequency. The prediction of long persistence in the absence of horizontal transfer was confirmed by stochastic simulations in finite populations. The average time to extinction of the endonuclease gene was found to be thousands of meiotic generations or more based on realistic parameter values. These results provide a solid theoretical basis for an understanding of these and other extremely selfish elements. PMID:19837694

  6. Spectroelectrochemical insights into structural and redox properties of immobilized endonuclease III and its catalytically inactive mutant

    NASA Astrophysics Data System (ADS)

    Moe, Elin; Rollo, Filipe; Silveira, Célia M.; Sezer, Murat; Hildebrandt, Peter; Todorovic, Smilja

    2018-01-01

    Endonuclease III is a Fe-S containing bifunctional DNA glycosylase which is involved in the repair of oxidation damaged DNA. Here we employ surface enhanced IR spectroelectrochemistry and electrochemistry to study the enzyme from the highly radiation- and desiccation-resistant bacterium Deinococcus radiodurans (DrEndoIII2). The experiments are designed to shed more light onto specific parameters that are currently proposed to govern damage search and recognition by endonucleases III. We demonstrate that electrostatic interactions required for the redox activation of DrEndoIII2 may result in high electric fields that alter its structural and thermodynamic properties. Analysis of inactive DrEndoIII2 (K132A/D150A double mutant) interacting with undamaged DNA, and the active enzyme interacting with damaged DNA also indicate that the electron transfer is modulated by subtle differences in the protein-DNA complex.

  7. Expression, functionality, and localization of apurinic/apyrimidinic endonucleases in replicative and non-replicative forms of Trypanosoma cruzi.

    PubMed

    Sepúlveda, S; Valenzuela, L; Ponce, I; Sierra, S; Bahamondes, P; Ramirez, S; Rojas, V; Kemmerling, U; Galanti, N; Cabrera, G

    2014-02-01

    Trypanosoma cruzi is the etiological agent of Chagas disease. The parasite has to overcome oxidative damage by ROS/RNS all along its life cycle to survive and to establish a chronic infection. We propose that T. cruzi is able to survive, among other mechanisms of detoxification, by repair of its damaged DNA through activation of the DNA base excision repair (BER) pathway. BER is highly conserved in eukaryotes with apurinic/apirimidinic endonucleases (APEs) playing a fundamental role. Previous results showed that T. cruzi exposed to hydrogen peroxide and peroxinitrite significantly decreases its viability when co-incubated with methoxyamine, an AP endonuclease inhibitor. In this work the localization, expression and functionality of two T. cruzi APEs (TcAP1, Homo sapiens APE1 orthologous and TcAP2, orthologous to Homo sapiens APE2 and to Schizosaccaromyces pombe Apn2p) were determined. These enzymes are present and active in the two replicative parasite forms (epimastigotes and amastigotes) as well as in the non-replicative, infective trypomastigotes. TcAP1 and TcAP2 are located in the nucleus of epimastigotes and their expression is constitutive. Epimastigote AP endonucleases as well as recombinant TcAP1 and TcAP2 are inhibited by methoxyamine. Overexpression of TcAP1 increases epimastigotes viability when they are exposed to acute ROS/RNS attack. This protective effect is more evident when parasites are submitted to persistent ROS/RNS exposition, mimicking nature conditions. Our results confirm that the BER pathway is involved in T. cruzi resistance to DNA oxidative damage and points to the participation of DNA AP endonucleases in parasite survival. © 2013 Wiley Periodicals, Inc.

  8. Homing endonucleases: from basics to therapeutic applications.

    PubMed

    Marcaida, Maria J; Muñoz, Inés G; Blanco, Francisco J; Prieto, Jesús; Montoya, Guillermo

    2010-03-01

    Homing endonucleases (HE) are double-stranded DNAses that target large recognition sites (12-40 bp). HE-encoding sequences are usually embedded in either introns or inteins. Their recognition sites are extremely rare, with none or only a few of these sites present in a mammalian-sized genome. However, these enzymes, unlike standard restriction endonucleases, tolerate some sequence degeneracy within their recognition sequence. Several members of this enzyme family have been used as templates to engineer tools to cleave DNA sequences that differ from their original wild-type targets. These custom HEs can be used to stimulate double-strand break homologous recombination in cells, to induce the repair of defective genes with very low toxicity levels. The use of tailored HEs opens up new possibilities for gene therapy in patients with monogenic diseases that can be treated ex vivo. This review provides an overview of recent advances in this field.

  9. Mlh1-Mlh3, a Meiotic Crossover and DNA Mismatch Repair Factor, Is a Msh2-Msh3-stimulated Endonuclease*

    PubMed Central

    Rogacheva, Maria V.; Manhart, Carol M.; Chen, Cheng; Guarne, Alba; Surtees, Jennifer; Alani, Eric

    2014-01-01

    Crossing over between homologous chromosomes is initiated in meiotic prophase in most sexually reproducing organisms by the appearance of programmed double strand breaks throughout the genome. In Saccharomyces cerevisiae the double-strand breaks are resected to form three prime single-strand tails that primarily invade complementary sequences in unbroken homologs. These invasion intermediates are converted into double Holliday junctions and then resolved into crossovers that facilitate homolog segregation during Meiosis I. Work in yeast suggests that Msh4-Msh5 stabilizes invasion intermediates and double Holliday junctions, which are resolved into crossovers in steps requiring Sgs1 helicase, Exo1, and a putative endonuclease activity encoded by the DNA mismatch repair factor Mlh1-Mlh3. We purified Mlh1-Mlh3 and showed that it is a metal-dependent and Msh2-Msh3-stimulated endonuclease that makes single-strand breaks in supercoiled DNA. These observations support a direct role for an Mlh1-Mlh3 endonuclease activity in resolving recombination intermediates and in DNA mismatch repair. PMID:24403070

  10. Mlh1-Mlh3, a meiotic crossover and DNA mismatch repair factor, is a Msh2-Msh3-stimulated endonuclease.

    PubMed

    Rogacheva, Maria V; Manhart, Carol M; Chen, Cheng; Guarne, Alba; Surtees, Jennifer; Alani, Eric

    2014-02-28

    Crossing over between homologous chromosomes is initiated in meiotic prophase in most sexually reproducing organisms by the appearance of programmed double strand breaks throughout the genome. In Saccharomyces cerevisiae the double-strand breaks are resected to form three prime single-strand tails that primarily invade complementary sequences in unbroken homologs. These invasion intermediates are converted into double Holliday junctions and then resolved into crossovers that facilitate homolog segregation during Meiosis I. Work in yeast suggests that Msh4-Msh5 stabilizes invasion intermediates and double Holliday junctions, which are resolved into crossovers in steps requiring Sgs1 helicase, Exo1, and a putative endonuclease activity encoded by the DNA mismatch repair factor Mlh1-Mlh3. We purified Mlh1-Mlh3 and showed that it is a metal-dependent and Msh2-Msh3-stimulated endonuclease that makes single-strand breaks in supercoiled DNA. These observations support a direct role for an Mlh1-Mlh3 endonuclease activity in resolving recombination intermediates and in DNA mismatch repair.

  11. Protein complexes formed during the incision reaction catalyzed by the Escherichia coli UvrABC endonuclease.

    PubMed Central

    Yeung, A T; Mattes, W B; Grossman, L

    1986-01-01

    An examination has been made into the nature of the nucleoprotein complexes formed during the incision reaction catalyzed by the Escherichia coli UvrABC endonuclease when acting on a pyrimidine dimer-containing fd RF-I DNA species. The complexes of proteins and DNA form in unique stages. The first stage of binding involves an ATP-stimulated interaction of the UvrA protein with duplex DNA containing pyrimidine dimer sites. The UvrB protein significantly stabilizes the UvrA-pyrimidine dimer containing DNA complex which, in turn, provides a foundation for the binding of UvrC to activate the UvrABC endonuclease. The binding of one molecule of UvrC to each UvrAB-damaged DNA complex is needed to catalyze incision in the vicinity of pyrimidine dimer sites. The UvrABC-DNA complex persists after the incision event suggesting that the lack of UvrABC turnover may be linked to other activities in the excision-repair pathway beyond the initial incision reaction. PMID:3960727

  12. Spectroelectrochemical insights into structural and redox properties of immobilized endonuclease III and its catalytically inactive mutant.

    PubMed

    Moe, Elin; Rollo, Filipe; Silveira, Célia M; Sezer, Murat; Hildebrandt, Peter; Todorovic, Smilja

    2018-01-05

    Endonuclease III is a Fe-S containing bifunctional DNA glycosylase which is involved in the repair of oxidation damaged DNA. Here we employ surface enhanced IR spectroelectrochemistry and electrochemistry to study the enzyme from the highly radiation- and desiccation-resistant bacterium Deinococcus radiodurans (DrEndoIII 2 ). The experiments are designed to shed more light onto specific parameters that are currently proposed to govern damage search and recognition by endonucleases III. We demonstrate that electrostatic interactions required for the redox activation of DrEndoIII 2 may result in high electric fields that alter its structural and thermodynamic properties. Analysis of inactive DrEndoIII 2 (K132A/D150A double mutant) interacting with undamaged DNA, and the active enzyme interacting with damaged DNA also indicate that the electron transfer is modulated by subtle differences in the protein-DNA complex. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. DNA Nucleotide Sequence Restricted by the RI Endonuclease

    PubMed Central

    Hedgpeth, Joe; Goodman, Howard M.; Boyer, Herbert W.

    1972-01-01

    The sequence of DNA base pairs adjacent to the phosphodiester bonds cleaved by the RI restriction endonuclease in unmodified DNA from coliphage λ has been determined. The 5′-terminal nucleotide labeled with 32P and oligonucleotides up to the heptamer were analyzed from a pancreatic DNase digest. The following sequence of nucleotides adjacent to the RI break made in λ DNA was deduced from these data and from the 3′-dinucleotide sequence and nearest-neighbor analysis obtained from repair synthesis with the DNA polymerase of Rous sarcoma virus [Formula: see text] The RI endonuclease cleavage of the phosphodiester bonds (indicated by arrows) generates 5′-phosphoryls and short cohesive termini of four nucleotides, pApApTpT. The most striking feature of the sequence is its symmetry. PMID:4343974

  14. Possibility of cytoplasmic pre-tRNA splicing: the yeast tRNA splicing endonuclease mainly localizes on the mitochondria.

    PubMed

    Yoshihisa, Tohru; Yunoki-Esaki, Kaori; Ohshima, Chie; Tanaka, Nobuyuki; Endo, Toshiya

    2003-08-01

    Pre-tRNA splicing has been believed to occur in the nucleus. In yeast, the tRNA splicing endonuclease that cleaves the exon-intron junctions of pre-tRNAs consists of Sen54p, Sen2p, Sen34p, and Sen15p and was thought to be an integral membrane protein of the inner nuclear envelope. Here we show that the majority of Sen2p, Sen54p, and the endonuclease activity are not localized in the nucleus, but on the mitochondrial surface. The endonuclease is peripherally associated with the cytosolic surface of the outer mitochondrial membrane. A Sen54p derivative artificially fixed on the mitochondria as an integral membrane protein can functionally replace the authentic Sen54p, whereas mutant proteins defective in mitochondrial localization are not fully active. sen2 mutant cells accumulate unspliced pre-tRNAs in the cytosol under the restrictive conditions, and this export of the pre-tRNAs partly depends on Los1p, yeast exportin-t. It is difficult to explain these results from the view of tRNA splicing in the nucleus. We rather propose a new possibility that tRNA splicing occurs on the mitochondrial surface in yeast.

  15. A new restriction endonuclease from Citrobacter freundii

    PubMed Central

    Janulaitis, A.A.; Stakenas, P.S.; Lebedenko, E.N.; Berlin, Yu.A.

    1982-01-01

    CfrI, a new restriction endonuclease of unique substrate specificity, has been isolated from a Citrobacter freundii strain. The enzyme recognizes a degenerated sequence PyGGCCPu in double-strand DNA and cleaves it between Py and G residues to yield 5′ -protruding tetranucleotide ends GGCC. Images PMID:6294607

  16. A newly discovered Bordetella species carries a transcriptionally active CRISPR-Cas with a small Cas9 endonuclease

    USDA-ARS?s Scientific Manuscript database

    The Cas9 endonuclease of the Type II-a clustered regularly interspersed short palindromic repeats (CRISPR), of Streptococcus pyogenes (SpCas9) has been adapted as a widely used tool for genome editing and genome engineering. Herein, we describe a gene encoding a novel Cas9 ortholog (BpsuCas9) and th...

  17. Creating a monomeric endonuclease TALE-I-SceI with high specificity and low genotoxicity in human cells.

    PubMed

    Lin, Jianfei; Chen, He; Luo, Ling; Lai, Yongrong; Xie, Wei; Kee, Kehkooi

    2015-01-01

    To correct a DNA mutation in the human genome for gene therapy, homology-directed repair (HDR) needs to be specific and have the lowest off-target effects to protect the human genome from deleterious mutations. Zinc finger nucleases, transcription activator-like effector nuclease (TALEN) and CRISPR-CAS9 systems have been engineered and used extensively to recognize and modify specific DNA sequences. Although TALEN and CRISPR/CAS9 could induce high levels of HDR in human cells, their genotoxicity was significantly higher. Here, we report the creation of a monomeric endonuclease that can recognize at least 33 bp by fusing the DNA-recognizing domain of TALEN (TALE) to a re-engineered homing endonuclease I-SceI. After sequentially re-engineering I-SceI to recognize 18 bp of the human β-globin sequence, the re-engineered I-SceI induced HDR in human cells. When the re-engineered I-SceI was fused to TALE (TALE-ISVB2), the chimeric endonuclease induced the same HDR rate at the human β-globin gene locus as that induced by TALEN, but significantly reduced genotoxicity. We further demonstrated that TALE-ISVB2 specifically targeted at the β-globin sequence in human hematopoietic stem cells. Therefore, this monomeric endonuclease has the potential to be used in therapeutic gene targeting in human cells. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  18. Effect of site-specific modification on restriction endonucleases and DNA modification methyltransferases.

    PubMed Central

    McClelland, M; Nelson, M; Raschke, E

    1994-01-01

    Restriction endonucleases have site-specific interactions with DNA that can often be inhibited by site-specific DNA methylation and other site-specific DNA modifications. However, such inhibition cannot generally be predicted. The empirically acquired data on these effects are tabulated for over 320 restriction endonucleases. In addition, a table of known site-specific DNA modification methyltransferases and their specificities is presented along with EMBL database accession numbers for cloned genes. PMID:7937074

  19. Comparison of genomes of malignant catarrhal fever-associated herpesviruses by restriction endonuclease analysis.

    PubMed

    Shih, L M; Zee, Y C; Castro, A E

    1989-01-01

    The restriction endonuclease DNA cleavage patterns of eight isolates of malignant catarrhal fever-associated herpesviruses were examined using the restriction endonucleases HindIII and EcoRI. The eight viruses could be assigned to two distinct groups. Virus isolates from a blue wildebeest, a sika deer and an ibex had restriction endonuclease DNA cleavage patterns that were in general similar to each other. The restriction pattern of these three viruses was distinct from the other five. Of these five, four were isolated from a greater kudu, a white tailed wildebeest, a white bearded wildebeest, and a cape hartebeest. The fifth isolate C500, was isolated from a domestic cow with malignant catarrhal fever. These five viruses had similar DNA cleavage patterns.

  20. Bacterial persistence by RNA endonucleases

    PubMed Central

    Maisonneuve, Etienne; Shakespeare, Lana J.; Jørgensen, Mikkel Girke; Gerdes, Kenn

    2011-01-01

    Bacteria form persisters, individual cells that are highly tolerant to different types of antibiotics. Persister cells are genetically identical to nontolerant kin but have entered a dormant state in which they are recalcitrant to the killing activity of the antibiotics. The molecular mechanisms underlying bacterial persistence are unknown. Here, we show that the ubiquitous Lon (Long Form Filament) protease and mRNA endonucleases (mRNases) encoded by toxin-antitoxin (TA) loci are required for persistence in Escherichia coli. Successive deletion of the 10 mRNase-encoding TA loci of E. coli progressively reduced the level of persisters, showing that persistence is a phenotype common to TA loci. In all cases tested, the antitoxins, which control the activities of the mRNases, are Lon substrates. Consistently, cells lacking lon generated a highly reduced level of persisters. Moreover, Lon overproduction dramatically increased the levels of persisters in wild-type cells but not in cells lacking the 10 mRNases. These results support a simple model according to which mRNases encoded by TA loci are activated in a small fraction of growing cells by Lon-mediated degradation of the antitoxins. Activation of the mRNases, in turn, inhibits global cellular translation, and thereby induces dormancy and persistence. Many pathogenic bacteria known to enter dormant states have a plethora of TA genes. Therefore, in the future, the discoveries described here may lead to a mechanistic understanding of the persistence phenomenon in pathogenic bacteria. PMID:21788497

  1. Structural aspects of catalytic mechanisms of endonucleases and their binding to nucleic acids

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

    Zhukhlistova, N. E.; Balaev, V. V.; Lyashenko, A. V.

    2012-05-15

    Endonucleases (EC 3.1) are enzymes of the hydrolase class that catalyze the hydrolytic cleavage of deoxyribonucleic and ribonucleic acids at any region of the polynucleotide chain. Endonucleases are widely used both in biotechnological processes and in veterinary medicine as antiviral agents. Medical applications of endonucleases in human cancer therapy hold promise. The results of X-ray diffraction studies of the spatial organization of endonucleases and their complexes and the mechanism of their action are analyzed and generalized. An analysis of the structural studies of this class of enzymes showed that the specific binding of enzymes to nucleic acids is characterized bymore » interactions with nitrogen bases and the nucleotide backbone, whereas the nonspecific binding of enzymes is generally characterized by interactions only with the nucleic-acid backbone. It should be taken into account that the specificity can be modulated by metal ions and certain low-molecular-weight organic compounds. To test the hypotheses about specific and nonspecific nucleic-acid-binding proteins, it is necessary to perform additional studies of atomic-resolution three-dimensional structures of enzyme-nucleic-acid complexes by methods of structural biology.« less

  2. Structural aspects of catalytic mechanisms of endonucleases and their binding to nucleic acids

    NASA Astrophysics Data System (ADS)

    Zhukhlistova, N. E.; Balaev, V. V.; Lyashenko, A. V.; Lashkov, A. A.

    2012-05-01

    Endonucleases (EC 3.1) are enzymes of the hydrolase class that catalyze the hydrolytic cleavage of deoxyribonucleic and ribonucleic acids at any region of the polynucleotide chain. Endonucleases are widely used both in biotechnological processes and in veterinary medicine as antiviral agents. Medical applications of endonucleases in human cancer therapy hold promise. The results of X-ray diffraction studies of the spatial organization of endonucleases and their complexes and the mechanism of their action are analyzed and generalized. An analysis of the structural studies of this class of enzymes showed that the specific binding of enzymes to nucleic acids is characterized by interactions with nitrogen bases and the nucleotide backbone, whereas the nonspecific binding of enzymes is generally characterized by interactions only with the nucleic-acid backbone. It should be taken into account that the specificity can be modulated by metal ions and certain low-molecular-weight organic compounds. To test the hypotheses about specific and nonspecific nucleic-acid-binding proteins, it is necessary to perform additional studies of atomic-resolution three-dimensional structures of enzyme-nucleic-acid complexes by methods of structural biology.

  3. A new endonuclease recognizing the deoxynucleotide sequence CCNNGG from the cyanobacterium Synechocystis 6701.

    PubMed

    Calléja, F; Tandeau de Marsac, N; Coursin, T; van Ormondt, H; de Waard, A

    1985-09-25

    A new sequence-specific endonuclease from the cyanobacterium Synechocystis species PCC 6701 has been purified and characterized. This enzyme, SecI, is unique in recognizing the nucleotide sequence: 5' -CCNNGG-3' 3' -GGNNCC-5' and cleaves it at the position indicated by the symbol. Two other restriction endonucleases, SecII and SecIII, found in this organism are isoschizomers of MspI and MstII, respectively.

  4. A new endonuclease recognizing the deoxynucleotide sequence CCNNGG from the cyanobacterium Synechocystis 6701.

    PubMed Central

    Calléja, F; Tandeau de Marsac, N; Coursin, T; van Ormondt, H; de Waard, A

    1985-01-01

    A new sequence-specific endonuclease from the cyanobacterium Synechocystis species PCC 6701 has been purified and characterized. This enzyme, SecI, is unique in recognizing the nucleotide sequence: 5' -CCNNGG-3' 3' -GGNNCC-5' and cleaves it at the position indicated by the symbol. Two other restriction endonucleases, SecII and SecIII, found in this organism are isoschizomers of MspI and MstII, respectively. Images PMID:2997722

  5. The complex between a four-way DNA junction and T7 endonuclease I

    PubMed Central

    Déclais, Anne-Cécile; Fogg, Jonathan M.; Freeman, Alasdair D.J.; Coste, Franck; Hadden, Jonathan M.; Phillips, Simon E.V.; Lilley, David M.J.

    2003-01-01

    The junction-resolving enzyme endonuclease I is selective for the structure of the DNA four-way (Holliday) junction. The enzyme binds to a four-way junction in two possible orientations, with a 4:1 ratio, opening the DNA structure at the centre and changing the global structure into a 90° cross of approximately coaxial helices. The nuclease cleaves the continuous strands of the junction in each orientation. Binding leads to pronounced regions of protection of the DNA against hydroxyl radical attack. Using all this information together with the known structure of the enzyme and the structure of the BglI–DNA complex, we have constructed a model of the complex of endonuclease I and a DNA junction. This shows how the enzyme is selective for the structure of a four-way junction, such that both continuous strands can be accommodated into the two active sites so that a productive resolution event is possible. PMID:12628932

  6. Lucanthone and Its Derivative Hycanthone Inhibit Apurinic Endonuclease-1 (APE1) by Direct Protein Binding

    PubMed Central

    Naidu, Mamta D.; Agarwal, Rakhi; Pena, Louis A.; Cunha, Luis; Mezei, Mihaly; Shen, Min; Wilson, David M.; Liu, Yuan; Sanchez, Zina; Chaudhary, Pankaj; Wilson, Samuel H.; Waring, Michael J.

    2011-01-01

    Lucanthone and hycanthone are thioxanthenone DNA intercalators used in the 1980s as antitumor agents. Lucanthone is in Phase I clinical trial, whereas hycanthone was pulled out of Phase II trials. Their potential mechanism of action includes DNA intercalation, inhibition of nucleic acid biosyntheses, and inhibition of enzymes like topoisomerases and the dual function base excision repair enzyme apurinic endonuclease 1 (APE1). Lucanthone inhibits the endonuclease activity of APE1, without affecting its redox activity. Our goal was to decipher the precise mechanism of APE1 inhibition as a prerequisite towards development of improved therapeutics that can counteract higher APE1 activity often seen in tumors. The IC50 values for inhibition of APE1 incision of depurinated plasmid DNA by lucanthone and hycanthone were 5 µM and 80 nM, respectively. The KD values (affinity constants) for APE1, as determined by BIACORE binding studies, were 89 nM for lucanthone/10 nM for hycanthone. APE1 structures reveal a hydrophobic pocket where hydrophobic small molecules like thioxanthenones can bind, and our modeling studies confirmed such docking. Circular dichroism spectra uncovered change in the helical structure of APE1 in the presence of lucanthone/hycanthone, and notably, this effect was decreased (Phe266Ala or Phe266Cys or Trp280Leu) or abolished (Phe266Ala/Trp280Ala) when hydrophobic site mutants were employed. Reduced inhibition by lucanthone of the diminished endonuclease activity of hydrophobic mutant proteins (as compared to wild type APE1) supports that binding of lucanthone to the hydrophobic pocket dictates APE1 inhibition. The DNA binding capacity of APE1 was marginally inhibited by lucanthone, and not at all by hycanthone, supporting our hypothesis that thioxanthenones inhibit APE1, predominantly, by direct interaction. Finally, lucanthone-induced degradation was drastically reduced in the presence of short and long lived free radical scavengers, e.g., TRIS and DMSO

  7. Comprehensive Conservation and Management Plan for Charlotte Harbor

    EPA Pesticide Factsheets

    This 2013 CCMP Update for Charlotte Harbor provides insight on the main priorities that the harbor is facing as well as research needed, restoration activities, legislative changes, and public outreach needs.

  8. Isolation, screening, and characterization of surface-active agent-producing, oil-degrading marine bacteria of Mumbai Harbor.

    PubMed

    Mohanram, Rajamani; Jagtap, Chandrakant; Kumar, Pradeep

    2016-04-15

    Diverse marine bacterial species predominantly found in oil-polluted seawater produce diverse surface-active agents. Surface-active agents produced by bacteria are classified into two groups based on their molecular weights, namely biosurfactants and bioemulsifiers. In this study, surface-active agent-producing, oil-degrading marine bacteria were isolated using a modified Bushnell-Haas medium with high-speed diesel as a carbon source from three oil-polluted sites of Mumbai Harbor. Surface-active agent-producing bacterial strains were screened using nine widely used methods. The nineteen bacterial strains showed positive results for more than four surface-active agent screening methods; further, these strains were characterized using biochemical and nucleic acid sequencing methods. Based on the results, the organisms belonged to the genera Acinetobacter, Alcanivorax, Bacillus, Comamonas, Chryseomicrobium, Halomonas, Marinobacter, Nesterenkonia, Pseudomonas, and Serratia. The present study confirmed the prevalence of surface-active agent-producing bacteria in the oil-polluted waters of Mumbai Harbor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Identification of the I38T PA Substitution as a Resistance Marker for Next-Generation Influenza Virus Endonuclease Inhibitors

    DOE PAGES

    Jones, Jeremy C.; Kumar, Gyanendra; Barman, Subrata; ...

    2018-04-24

    ABSTRACT The clinical severity and annual occurrence of influenza virus epidemics, combined with the availability of just a single class of antivirals to treat infections, underscores the urgent need to develop new anti-influenza drugs. The endonuclease activity within the viral acidic polymerase (PA) protein is an attractive target for drug discovery due to the critical role it plays in viral gene transcription. RO-7 is a next-generation PA endonuclease inhibitor of influenza A and B viruses, but its drug resistance potential is unknown. Through serial passage of influenza A(H1N1) viruses in MDCK cells under selective pressure of RO-7, we identified anmore » I38T substitution within the PA endonuclease domain that conferred in vitro resistance to RO-7 (up to a 287-fold change in 50% effective concentration [EC 50 ]). I38T emerged between 5 and 10 passages, and when introduced into recombinant influenza A(H1N1) viruses, alone conferred RO-7 resistance (up to an 81-fold change in EC 50 ). Cocrystal structures of mutant and wild-type endonuclease domains with RO-7 provided the structural basis of resistance, where a key hydrophobic interaction between RO-7 and the Ile38 side chain is compromised when mutated to the polar threonine. While Ile38 does not have a crucial role in coordinating the endonuclease active site, the switch to threonine does affect the polymerase activity of some viruses and influences RO-7 affinity for the PA N target (i.e., the ≈200-residue N-terminal domain of PA). However, the change does not lead to a complete loss of replication activity in vitro . Our results predict that RO-7-resistant influenza viruses carrying the I38T substitution may emerge under treatment. This should be taken into consideration for clinical surveillance and in refinement of these drugs. IMPORTANCE The effectiveness of antiviral drugs can be severely compromised by the emergence of resistant viruses. Therefore, determination of the mechanisms by which viruses

  10. Identification of the I38T PA Substitution as a Resistance Marker for Next-Generation Influenza Virus Endonuclease Inhibitors

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

    Jones, Jeremy C.; Kumar, Gyanendra; Barman, Subrata

    ABSTRACT The clinical severity and annual occurrence of influenza virus epidemics, combined with the availability of just a single class of antivirals to treat infections, underscores the urgent need to develop new anti-influenza drugs. The endonuclease activity within the viral acidic polymerase (PA) protein is an attractive target for drug discovery due to the critical role it plays in viral gene transcription. RO-7 is a next-generation PA endonuclease inhibitor of influenza A and B viruses, but its drug resistance potential is unknown. Through serial passage of influenza A(H1N1) viruses in MDCK cells under selective pressure of RO-7, we identified anmore » I38T substitution within the PA endonuclease domain that conferred in vitro resistance to RO-7 (up to a 287-fold change in 50% effective concentration [EC 50 ]). I38T emerged between 5 and 10 passages, and when introduced into recombinant influenza A(H1N1) viruses, alone conferred RO-7 resistance (up to an 81-fold change in EC 50 ). Cocrystal structures of mutant and wild-type endonuclease domains with RO-7 provided the structural basis of resistance, where a key hydrophobic interaction between RO-7 and the Ile38 side chain is compromised when mutated to the polar threonine. While Ile38 does not have a crucial role in coordinating the endonuclease active site, the switch to threonine does affect the polymerase activity of some viruses and influences RO-7 affinity for the PA N target (i.e., the ≈200-residue N-terminal domain of PA). However, the change does not lead to a complete loss of replication activity in vitro . Our results predict that RO-7-resistant influenza viruses carrying the I38T substitution may emerge under treatment. This should be taken into consideration for clinical surveillance and in refinement of these drugs. IMPORTANCE The effectiveness of antiviral drugs can be severely compromised by the emergence of resistant viruses. Therefore, determination of the mechanisms by which viruses

  11. BplI, a new BcgI-like restriction endonuclease, which recognizes a symmetric sequence.

    PubMed Central

    Vitkute, J; Maneliene, Z; Petrusyte, M; Janulaitis, A

    1997-01-01

    Bcg I and Bcg I-like restriction endonucleases cleave double stranded DNA specifically on both sides of their asymmetric recognition sequences which are interrupted by several ambiguous base pairs. Their heterosubunit structure, bifunctionality and stimulation by AdoMet make them different from other classified restriction enzymes. Here we report on a new Bcg I-like restriction endonuclease, Bpl I from Bacillus pumilus , which in contrast to all other Bcg I-like enzymes, recognizes a symmetric interrupted sequence, and which, like Bcg I, cleaves double stranded DNA upstream and downstream of its recognition sequence (8/13)GAGN5CTC(13/8). Like Bcg I, Bpl I is a bifunctional enzyme revealing both DNA cleavage and methyltransferase activities. There are two polypeptides in the homogeneous preparation of Bpl I with molecular masses of approximately 74 and 37 kDa. The sizes of the Bpl I subunits are close to those of Bcg I, but the proportion 1:1 in the final preparation is different from that of 2:1 in Bcg I. Low activity observed with Mg2+increases >100-fold in the presence of AdoMet. Even with AdoMet though, specific cleavage is incomplete. S -adenosylhomocysteine (AdoHcy) or sinefungin can replace AdoMet in the cleavage reaction. AdoHcy activated Bpl I yields complete cleavage of DNA. PMID:9358150

  12. CNG site-specific and methyl-sensitive endonuclease WEN1 from wheat seedlings.

    PubMed

    Fedoreyeva, L I; Vanyushin, B F

    2011-06-01

    Endonuclease WEN1 with apparent molecular mass about 27 kDa isolated from cytoplasmic vesicular fraction of aging coleoptiles of wheat seedlings has expressed site specificity action. This is a first detection and isolation of a site-specific endonuclease from higher eukaryotes, in general, and higher plants, in particular. The enzyme hydrolyzes deoxyribooligonucleotides of different composition on CNG (N is G, A, C, or T) sites by splitting the phosphodiester bond between C and N nucleotide residues in CNG sequence independent from neighbor nucleotide context except for CCCG. WEN1 prefers to hydrolyze methylated λ phage DNA and double-stranded deoxyribooligonucleotides containing 5-methylcytosine sites (m(5)CAG, m(5)CTG) compared with unmethylated substrates. The enzyme is also able to hydrolyze single-stranded substrates, but in this case it splits unmethylated substrates predominantly. Detection in wheat seedlings of WEN1 endonuclease that is site specific, sensitive to the substrate methylation status, and modulated with S-adenosyl-L-methionine indicates that in higher plants restriction--modification systems or some of their elements, at least, may exist.

  13. Salient Features of Endonuclease Platforms for Therapeutic Genome Editing.

    PubMed

    Certo, Michael T; Morgan, Richard A

    2016-03-01

    Emerging gene-editing technologies are nearing a revolutionary phase in genetic medicine: precisely modifying or repairing causal genetic defects. This may include any number of DNA sequence manipulations, such as knocking out a deleterious gene, introducing a particular mutation, or directly repairing a defective sequence by site-specific recombination. All of these edits can currently be achieved via programmable rare-cutting endonucleases to create targeted DNA breaks that can engage and exploit endogenous DNA repair pathways to impart site-specific genetic changes. Over the past decade, several distinct technologies for introducing site-specific DNA breaks have been developed, yet the different biological origins of these gene-editing technologies bring along inherent differences in parameters that impact clinical implementation. This review aims to provide an accessible overview of the various endonuclease-based gene-editing platforms, highlighting the strengths and weakness of each with respect to therapeutic applications.

  14. Salient Features of Endonuclease Platforms for Therapeutic Genome Editing

    PubMed Central

    Certo, Michael T; Morgan, Richard A

    2016-01-01

    Emerging gene-editing technologies are nearing a revolutionary phase in genetic medicine: precisely modifying or repairing causal genetic defects. This may include any number of DNA sequence manipulations, such as knocking out a deleterious gene, introducing a particular mutation, or directly repairing a defective sequence by site-specific recombination. All of these edits can currently be achieved via programmable rare-cutting endonucleases to create targeted DNA breaks that can engage and exploit endogenous DNA repair pathways to impart site-specific genetic changes. Over the past decade, several distinct technologies for introducing site-specific DNA breaks have been developed, yet the different biological origins of these gene-editing technologies bring along inherent differences in parameters that impact clinical implementation. This review aims to provide an accessible overview of the various endonuclease-based gene-editing platforms, highlighting the strengths and weakness of each with respect to therapeutic applications. PMID:26796671

  15. Receptor-Mediated Delivery of CRISPR-Cas9 Endonuclease for Cell-Type-Specific Gene Editing.

    PubMed

    Rouet, Romain; Thuma, Benjamin A; Roy, Marc D; Lintner, Nathanael G; Rubitski, David M; Finley, James E; Wisniewska, Hanna M; Mendonsa, Rima; Hirsh, Ariana; de Oñate, Lorena; Compte Barrón, Joan; McLellan, Thomas J; Bellenger, Justin; Feng, Xidong; Varghese, Alison; Chrunyk, Boris A; Borzilleri, Kris; Hesp, Kevin D; Zhou, Kaihong; Ma, Nannan; Tu, Meihua; Dullea, Robert; McClure, Kim F; Wilson, Ross C; Liras, Spiros; Mascitti, Vincent; Doudna, Jennifer A

    2018-05-30

    CRISPR-Cas RNA-guided endonucleases hold great promise for disrupting or correcting genomic sequences through site-specific DNA cleavage and repair. However, the lack of methods for cell- and tissue-selective delivery currently limits both research and clinical uses of these enzymes. We report the design and in vitro evaluation of S. pyogenes Cas9 proteins harboring asialoglycoprotein receptor ligands (ASGPrL). In particular, we demonstrate that the resulting ribonucleoproteins (Cas9-ASGPrL RNP) can be engineered to be preferentially internalized into cells expressing the corresponding receptor on their surface. Uptake of such fluorescently labeled proteins in liver-derived cell lines HEPG2 (ASGPr+) and SKHEP (control; diminished ASGPr) was studied by live cell imaging and demonstrates increased accumulation of Cas9-ASGPrL RNP in HEPG2 cells as a result of effective ASGPr-mediated endocytosis. When uptake occurred in the presence of a peptide with endosomolytic properties, we observed receptor-facilitated and cell-type specific gene editing that did not rely on electroporation or the use of transfection reagents. Overall, these in vitro results validate the receptor-mediated delivery of genome-editing enzymes as an approach for cell-selective gene editing and provide a framework for future potential applications to hepatoselective gene editing in vivo.

  16. Probing the dynamics of restriction endonuclease NgoMIV-DNA interaction by single-molecule FRET.

    PubMed

    Tutkus, Marijonas; Sasnauskas, Giedrius; Rutkauskas, Danielis

    2017-12-01

    Many type II restriction endonucleases require two copies of their recognition sequence for optimal activity. Concomitant binding of two DNA sites by such an enzyme produces a DNA loop. Here we exploit single-molecule Förster resonance energy transfer (smFRET) of surface-immobilized DNA fragments to study the dynamics of DNA looping induced by tetrameric endonuclease NgoMIV. We have employed a DNA fragment with two NgoMIV recognition sites and a FRET dye pair such that upon protein-induced DNA looping the dyes are brought to close proximity resulting in a FRET signal. The dynamics of DNA-NgoMIV interactions proved to be heterogeneous, with individual smFRET trajectories exhibiting broadly different average looped state durations. Distinct types of the dynamics were attributed to different types of DNA-protein complexes, mediated either by one NgoMIV tetramer simultaneously bound to two specific sites ("slow" trajectories) or by semi-specific interactions of two DNA-bound NgoMIV tetramers ("fast" trajectories), as well as to conformational heterogeneity of individual NgoMIV molecules. © 2017 Wiley Periodicals, Inc.

  17. Aromatic residues located close to the active center are essential for the catalytic reaction of flap endonuclease-1 from hyperthermophilic archaeon Pyrococcus horikoshii.

    PubMed

    Matsui, Eriko; Abe, Junko; Yokoyama, Hideshi; Matsui, Ikuo

    2004-04-16

    Flap endonuclease-1 (FEN-1) possessing 5'-flap endonuclease and 5'-->3' exonuclease activity plays important roles in DNA replication and repair. In this study, the kinetic parameters of mutants at highly conserved aromatic residues, Tyr33, Phe35, Phe79, and Phe278-Phe279, in the vicinity of the catalytic centers of FEN-1 were examined. The substitution of these aromatic residues with alanine led to a large reduction in kcat values, although these mutants retained Km values similar to that of the wild-type enzyme. Notably, the kcat of Y33A and F79A decreased 333-fold and 71-fold, respectively, compared with that of the wild-type enzyme. The aromatic residues Tyr33 and Phe79, and the aromatic cluster Phe278-Phe279 mainly contributed to the recognition of the substrates without the 3' projection of the upstream strand (the nick, 5'-recess-end, single-flap, and pseudo-Y substrates) for the both exo- and endo-activities, but played minor roles in recognizing the substrates with the 3' projection (the double flap substrate and the nick substrate with the 3' projection). The replacement of Tyr33, Phe79, and Phe278-Phe279, with non-charged aromatic residues, but not with aliphatic hydrophobic residues, recovered the kcat values almost fully for the substrates without the 3' projection of the upstream strand, suggesting that the aromatic groups of Tyr33, Phe79, and Phe278-Phe279 might be involved in the catalytic reaction, probably via multiple stacking interactions with nucleotide bases. The stacking interactions of Tyr33 and Phe79 might play important roles in fixing the template strand and the downstream strand, respectively, in close proximity to the active center to achieve the productive transient state leading to the hydrolysis.

  18. An open reading frame in intron seven of the sea urchin DNA-methyltransferase gene codes for a functional AP1 endonuclease.

    PubMed

    Cioffi, Anna Valentina; Ferrara, Diana; Cubellis, Maria Vittoria; Aniello, Francesco; Corrado, Marcella; Liguori, Francesca; Amoroso, Alessandro; Fucci, Laura; Branno, Margherita

    2002-08-01

    Analysis of the genome structure of the Paracentrotus lividus (sea urchin) DNA methyltransferase (DNA MTase) gene showed the presence of an open reading frame, named METEX, in intron 7 of the gene. METEX expression is developmentally regulated, showing no correlation with DNA MTase expression. In fact, DNA MTase transcripts are present at high concentrations in the early developmental stages, while METEX is expressed at late stages of development. Two METEX cDNA clones (Met1 and Met2) that are different in the 3' end have been isolated in a cDNA library screening. The putative translated protein from Met2 cDNA clone showed similarity with Escherichia coli endonuclease III on the basis of sequence and predictive three-dimensional structure. The protein, overexpressed in E. coli and purified, had functional properties similar to the endonuclease specific for apurinic/apyrimidinic (AP) sites on the basis of the lyase activity. Therefore the open reading frame, present in intron 7 of the P. lividus DNA MTase gene, codes for a functional AP endonuclease designated SuAP1.

  19. CgII cleaves DNA using a mechanism distinct from other ATP-dependent restriction endonucleases

    PubMed Central

    Toliusis, Paulius; Silanskas, Arunas; Szczelkun, Mark D.

    2017-01-01

    Abstract The restriction endonuclease CglI from Corynebacterium glutamicum recognizes an asymmetric 5′-GCCGC-3′ site and cleaves the DNA 7 and 6/7 nucleotides downstream on the top and bottom DNA strands, respectively, in an NTP-hydrolysis dependent reaction. CglI is composed of two different proteins: an endonuclease (R.CglI) and a DEAD-family helicase-like ATPase (H.CglI). These subunits form a heterotetrameric complex with R2H2 stoichiometry. However, the R2H2·CglI complex has only one nuclease active site sufficient to cut one DNA strand suggesting that two complexes are required to introduce a double strand break. Here, we report studies to evaluate the DNA cleavage mechanism of CglI. Using one- and two-site circular DNA substrates we show that CglI does not require two sites on the same DNA for optimal catalytic activity. However, one-site linear DNA is a poor substrate, supporting a mechanism where CglI complexes must communicate along the one-dimensional DNA contour before cleavage is activated. Based on experimental data, we propose that adenosine triphosphate (ATP) hydrolysis by CglI produces translocation on DNA preferentially in a downstream direction from the target, although upstream translocation is also possible. Our results are consistent with a mechanism of CglI action that is distinct from that of other ATP-dependent restriction-modification enzymes. PMID:28854738

  20. Purification of Restriction Endonuclease EcoRII and its Co-Crystallization

    NASA Technical Reports Server (NTRS)

    Karpova, E. A.; Chen, L.; Meehan, E.; Pusey, M.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Restriction endonuclease EcoRII (EcoRII) is a homodimeric DNA-binding protein. It belongs to the type II family of restriction-modification enzymes (subclass IIe). EcoRII recognizes the nucleotide sequence 5'-CCWGG (W=A or T) and cleaves the phosphodiester bond preceding the first cytosine. Methylation at C5 of the second cytosine inhibits cleavage. The enzyme has a unique ability to search for the presence of two substrate sites before cleavage. To the best of our knowledge no other subclass IIe restriction endonuclease has been crystallized yet, without or with a DNA-substrate. We have recently grown and characterized the crystals of this enzyme (1) Here we report on the result of co-crystallization experiments of EcoRII with an 11 b.p. oligonucleotide substrate. The dissociation constant (Kd) EcoRII: 11 b.p. was determined earlier (unpublished results). The needle-like crystals of oligonucleotide-EcoRII protein complex were obtained with this substrate by the technique of vapor diffusion hanging drops. The crystals obtained were washed and dissolved in an aliquot of 10 mM Tris-HCl buffer, pH=7.5. Running a portion of this solution on the SDS-get indicated the presence of endonuclease in the solution. A UV-spectrophotometric test of a second portion confirmed the presence of DNA. We are now working on improvement of the DNA-EcoRII protein crystals. Results obtained from these and ongoing efforts will be reported.

  1. [Definition of the specificity of DNA-methyltransferase M.Bsc4I in cell lysate by blocking of restriction endonucleases and computer modeling].

    PubMed

    Dedkov, V S

    2009-01-01

    The specificity of DNA-methyltransferase M.Bsc4I was defined in cellular lysate of Bacillus schlegelii 4. For this purpose, we used methylation sensitivity of restriction endonucleases, and also modeling of methylation. The modeling consisted in editing sequences of DNA using replacements of methylated bases and their complementary bases. The substratum DNA processed by M.Bsc4I also were used for studying sensitivity of some restriction endonucleases to methylation. Thus, it was shown that M.Bsc4I methylated 5'-Cm4CNNNNNNNGG-3' and the overlapped dcm-methylation blocked its activity. The offered approach can appear universal enough and simple for definition of specificity of DNA-methyltransferases.

  2. The role of His-83 of yeast apurinic/apyrimidinic endonuclease Apn1 in catalytic incision of abasic sites in DNA.

    PubMed

    Dyakonova, Elena S; Koval, Vladimir V; Lomzov, Alexander A; Ishchenko, Alexander A; Fedorova, Olga S

    2015-06-01

    The apurinic/apyrimidinic (AP) endonuclease Apn1 from Saccharomyces cerevisiae is a key enzyme involved in the base excision repair (BER) at the cleavage stage of abasic sites (AP sites) in DNA. The crystal structure of Apn1 from S. cerevisiae is unresolved. Based on its high amino acid homology to Escherichia coli Endo IV, His-83 is believed to coordinate one of three Zn2+ ions in Apn1's active site similar to His-69 in Endo IV. Substituting His-83 with Ala is proposed to decrease the AP endonuclease activity of Apn1 owing to weak coordination of Zn2+ ions involved in enzymatic catalysis. The kinetics of recognition, binding, and incision of DNA substrates with the H83A Apn1 mutant was investigated. The stopped-flow method detecting fluorescence intensity changes of 2-aminopurine (2-aPu) was used to monitor the conformational dynamics of DNA at pre-steady-state conditions. We found substituting His-83 with Ala influenced catalytic complex formation and further incision of the damaged DNA strand. The H83A Apn1 catalysis depends not only on the location of the mismatch relative to the abasic site in DNA, but also on the nature of damage. We consider His-83 properly coordinates the active site Zn2+ ion playing a crucial role in catalytic incision stage. Our data prove suppressed enzymatic activity of H83A Apn1 results from the reduced number of active site Zn2+ ions. Our study provides insights into mechanistic specialty of AP site repair by yeast AP endonuclease Apn1 of Endo IV family, which members are not found in mammals, but are present in many microorganisms. The results will provide useful guidelines for design of new anti-fungal and anti-malarial agents. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Double-stranded endonuclease activity in Bacillus halodurans clustered regularly interspaced short palindromic repeats (CRISPR)-associated Cas2 protein.

    PubMed

    Nam, Ki Hyun; Ding, Fran; Haitjema, Charles; Huang, Qingqiu; DeLisa, Matthew P; Ke, Ailong

    2012-10-19

    The CRISPR (clustered regularly interspaced short palindromic repeats) system is a prokaryotic RNA-based adaptive immune system against extrachromosomal genetic elements. Cas2 is a universally conserved core CRISPR-associated protein required for the acquisition of new spacers for CRISPR adaptation. It was previously characterized as an endoribonuclease with preference for single-stranded (ss)RNA. Here, we show using crystallography, mutagenesis, and isothermal titration calorimetry that the Bacillus halodurans Cas2 (Bha_Cas2) from the subtype I-C/Dvulg CRISPR instead possesses metal-dependent endonuclease activity against double-stranded (ds)DNA. This activity is consistent with its putative function in producing new spacers for insertion into the 5'-end of the CRISPR locus. Mutagenesis and isothermal titration calorimetry studies revealed that a single divalent metal ion (Mg(2+) or Mn(2+)), coordinated by a symmetric Asp pair in the Bha_Cas2 dimer, is involved in the catalysis. We envision that a pH-dependent conformational change switches Cas2 into a metal-binding competent conformation for catalysis. We further propose that the distinct substrate preferences among Cas2 proteins may be determined by the sequence and structure in the β1-α1 loop.

  4. Karyopherin-mediated nuclear import of the homing endonuclease VMA1-derived endonuclease is required for self-propagation of the coding region.

    PubMed

    Nagai, Yuri; Nogami, Satoru; Kumagai-Sano, Fumi; Ohya, Yoshikazu

    2003-03-01

    VMA1-derived endonuclease (VDE), a site-specific endonuclease in Saccharomyces cerevisiae, enters the nucleus to generate a double-strand break in the VDE-negative allelic locus, mediating the self-propagating gene conversion called homing. Although VDE is excluded from the nucleus in mitotic cells, it relocalizes at premeiosis, becoming localized in both the nucleus and the cytoplasm in meiosis. The nuclear localization of VDE is induced by inactivation of TOR kinases, which constitute central regulators of cell differentiation in S. cerevisiae, and by nutrient depletion. A functional genomic approach revealed that at least two karyopherins, Srp1p and Kap142p, are required for the nuclear localization pattern. Genetic and physical interactions between Srp1p and VDE imply direct involvement of karyopherin-mediated nuclear transport in this process. Inactivation of TOR signaling or acquisition of an extra nuclear localization signal in the VDE coding region leads to artificial nuclear localization of VDE and thereby induces homing even during mitosis. These results serve as evidence that VDE utilizes the host systems of nutrient signal transduction and nucleocytoplasmic transport to ensure the propagation of its coding region.

  5. Karyopherin-Mediated Nuclear Import of the Homing Endonuclease VMA1-Derived Endonuclease Is Required for Self-Propagation of the Coding Region

    PubMed Central

    Nagai, Yuri; Nogami, Satoru; Kumagai-Sano, Fumi; Ohya, Yoshikazu

    2003-01-01

    VMA1-derived endonuclease (VDE), a site-specific endonuclease in Saccharomyces cerevisiae, enters the nucleus to generate a double-strand break in the VDE-negative allelic locus, mediating the self-propagating gene conversion called homing. Although VDE is excluded from the nucleus in mitotic cells, it relocalizes at premeiosis, becoming localized in both the nucleus and the cytoplasm in meiosis. The nuclear localization of VDE is induced by inactivation of TOR kinases, which constitute central regulators of cell differentiation in S. cerevisiae, and by nutrient depletion. A functional genomic approach revealed that at least two karyopherins, Srp1p and Kap142p, are required for the nuclear localization pattern. Genetic and physical interactions between Srp1p and VDE imply direct involvement of karyopherin-mediated nuclear transport in this process. Inactivation of TOR signaling or acquisition of an extra nuclear localization signal in the VDE coding region leads to artificial nuclear localization of VDE and thereby induces homing even during mitosis. These results serve as evidence that VDE utilizes the host systems of nutrient signal transduction and nucleocytoplasmic transport to ensure the propagation of its coding region. PMID:12588991

  6. Purification and characterization of VDE, a site-specific endonuclease from the yeast Saccharomyces cerevisiae.

    PubMed

    Gimble, F S; Thorner, J

    1993-10-15

    The 119-kDa primary translation product of the VMA1 gene of Saccharomyces cerevisiae undergoes a self-catalyzed rearrangement ("protein splicing") that excises an internal 50-kDa segment of the polypeptide and joins the amino-terminal and carboxyl-terminal segments to generate the 69-kDa subunit of the vacuolar membrane-associated H(+)-ATPase. We have shown previously that the internal segment is a site-specific endonuclease (Gimble, F. S., and Thorner, J. (1992) Nature 357, 301-306). Here we describe methods for the high level expression and purification to near homogeneity of both the authentic VMA1-derived endonuclease (or VDE) from yeast (yield 18%) and a recombinant form of VDE made in bacteria (yield 29%). Detailed characterization of these preparations demonstrated that the yeast-derived and bacterially produced enzymes were indistinguishable, as judged by: (a) behavior during purification; (b) apparent native molecular mass (50 kDa); (c) immunological reactivity; and (d) catalytic properties (specific activity; cleavage site recognition; and optima for pH, temperature, divalent cation and ionic strength). The minimal site required for VDE cleavage was delimited to a 30-base pair sequence within its specific substrate (the VMA1 delta vde allele).

  7. Comparison of the nucleotide and amino acid sequences of the RsrI and EcoRI restriction endonucleases.

    PubMed

    Stephenson, F H; Ballard, B T; Boyer, H W; Rosenberg, J M; Greene, P J

    1989-12-21

    The RsrI endonuclease, a type-II restriction endonuclease (ENase) found in Rhodobacter sphaeroides, is an isoschizomer of the EcoRI ENase. A clone containing an 11-kb BamHI fragment was isolated from an R. sphaeroides genomic DNA library by hybridization with synthetic oligodeoxyribonucleotide probes based on the N-terminal amino acid (aa) sequence of RsrI. Extracts of E. coli containing a subclone of the 11-kb fragment display RsrI activity. Nucleotide sequence analysis reveals an 831-bp open reading frame encoding a polypeptide of 277 aa. A 50% identity exists within a 266-aa overlap between the deduced aa sequences of RsrI and EcoRI. Regions of 75-100% aa sequence identity correspond to key structural and functional regions of EcoRI. The type-II ENases have many common properties, and a common origin might have been expected. Nevertheless, this is the first demonstration of aa sequence similarity between ENases produced by different organisms.

  8. Inhibitors of nuclease and redox activity of apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1).

    PubMed

    Laev, Sergey S; Salakhutdinov, Nariman F; Lavrik, Olga I

    2017-05-01

    Human apurinic/apyrimidinic endonuclease 1/redox effector factor 1 (APE1/Ref-1) is a multifunctional protein which is essential in the base excision repair (BER) pathway of DNA lesions caused by oxidation and alkylation. This protein hydrolyzes DNA adjacent to the 5'-end of an apurinic/apyrimidinic (AP) site to produce a nick with a 3'-hydroxyl group and a 5'-deoxyribose phosphate moiety or activates the DNA-binding activity of certain transcription factors through its redox function. Studies have indicated a role for APE1/Ref-1 in the pathogenesis of cancer and in resistance to DNA-interactive drugs. Thus, this protein has potential as a target in cancer treatment. As a result, major efforts have been directed to identify small molecule inhibitors against APE1/Ref-1 activities. These agents have the potential to become anticancer drugs. The aim of this review is to present recent progress in studies of all published small molecule APE1/Ref-1 inhibitors. The structures and activities of APE1/Ref-1 inhibitors, that target both DNA repair and redox activities, are presented and discussed. To date, there is an urgent need for further development of the design and synthesis of APE1/Ref-1 inhibitors due to high importance of this protein target. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Progressive engineering of a homing endonuclease genome editing reagent for the murine X-linked immunodeficiency locus

    PubMed Central

    Wang, Yupeng; Khan, Iram F.; Boissel, Sandrine; Jarjour, Jordan; Pangallo, Joseph; Thyme, Summer; Baker, David; Scharenberg, Andrew M.; Rawlings, David J.

    2014-01-01

    LAGLIDADG homing endonucleases (LHEs) are compact endonucleases with 20–22 bp recognition sites, and thus are ideal scaffolds for engineering site-specific DNA cleavage enzymes for genome editing applications. Here, we describe a general approach to LHE engineering that combines rational design with directed evolution, using a yeast surface display high-throughput cleavage selection. This approach was employed to alter the binding and cleavage specificity of the I-Anil LHE to recognize a mutation in the mouse Bruton tyrosine kinase (Btk) gene causative for mouse X-linked immunodeficiency (XID)—a model of human X-linked agammaglobulinemia (XLA). The required re-targeting of I-AniI involved progressive resculpting of the DNA contact interface to accommodate nine base differences from the native cleavage sequence. The enzyme emerging from the progressive engineering process was specific for the XID mutant allele versus the wild-type (WT) allele, and exhibited activity equivalent to WT I-AniI in vitro and in cellulo reporter assays. Fusion of the enzyme to a site-specific DNA binding domain of transcription activator-like effector (TALE) resulted in a further enhancement of gene editing efficiency. These results illustrate the potential of LHE enzymes as specific and efficient tools for therapeutic genome engineering. PMID:24682825

  10. Structural and functional characterization of two unusual endonuclease III enzymes from Deinococcus radiodurans.

    PubMed

    Sarre, Aili; Ökvist, Mats; Klar, Tobias; Hall, David R; Smalås, Arne O; McSweeney, Sean; Timmins, Joanna; Moe, Elin

    2015-08-01

    While most bacteria possess a single gene encoding the bifunctional DNA glycosylase Endonuclease III (EndoIII) in their genomes, Deinococcus radiodurans possesses three: DR2438 (DrEndoIII1), DR0289 (DrEndoIII2) and DR0982 (DrEndoIII3). Here we have determined the crystal structures of DrEndoIII1 and an N-terminally truncated form of DrEndoIII3 (DrEndoIII3Δ76). We have also generated a homology model of DrEndoIII2 and measured activity of the three enzymes. All three structures consist of two all α-helical domains, one of which exhibits a [4Fe-4S] cluster and the other a HhH-motif, separated by a DNA binding cleft, similar to previously determined structures of endonuclease III from Escherichia coli and Geobacillus stearothermophilus. However, both DrEndoIII1 and DrEndoIII3 possess an extended HhH motif with extra helical features and an altered electrostatic surface potential. In addition, the DNA binding cleft of DrEndoIII3 seems to be less accessible for DNA interactions, while in DrEndoIII1 it seems to be more open. Analysis of the enzyme activities shows that DrEndoIII2 is most similar to the previously studied enzymes, while DrEndoIII1 seems to be more distant with a weaker activity towards substrate DNA containing either thymine glycol or an abasic site. DrEndoIII3 is the most distantly related enzyme and displays no detectable activity towards these substrates even though the suggested catalytic residues are conserved. Based on a comparative structural analysis, we suggest that the altered surface potential, shape of the substrate-binding pockets and specific amino acid substitutions close to the active site and in the DNA interacting loops may underlie the unexpected differences in activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. RNA-dependent DNA endonuclease Cas9 of the CRISPR system: Holy Grail of genome editing?

    PubMed

    Gasiunas, Giedrius; Siksnys, Virginijus

    2013-11-01

    Tailor-made nucleases for precise genome modification, such as zinc finger or TALE nucleases, currently represent the state-of-the-art for genome editing. These nucleases combine a programmable protein module which guides the enzyme to the target site with a nuclease domain which cuts DNA at the addressed site. Reprogramming of these nucleases to cut genomes at specific locations requires major protein engineering efforts. RNA-guided DNA endonuclease Cas9 of the type II (clustered regularly interspaced short palindromic repeat) CRISPR-Cas system uses CRISPR RNA (crRNA) as a guide to locate the DNA target and the Cas9 protein to cut DNA. Easy programmability of the Cas9 endonuclease using customizable RNAs brings unprecedented flexibility and versatility for targeted genome modification. We highlight the potential of the Cas9 RNA-guided DNA endonuclease as a novel tool for genome surgery, and discuss possible constraints and future prospects. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Assembly of Francisella novicida Cpf1 endonuclease in complex with guide RNA and target DNA

    PubMed Central

    Montoya, Guillermo; Stella, Stefano

    2017-01-01

    Bacteria and archaea use the CRISPR–Cas system as an adaptive response against infection by foreign nucleic acids. Owing to its remarkable flexibility, this mechanism has been harnessed and adopted as a powerful tool for genome editing. The CRISPR–Cas system includes two classes that are subdivided into six types and 19 subtypes according to conservation of the cas gene and loci organization. Recently, a new protein with endonuclease activity belonging to class 2 type V has been identified. This endonuclease, termed Cpf1, in complex with a single CRISPR RNA (crRNA) is able to recognize and cleave a target DNA preceded by a 5′-TTN-3′ protospacer-adjacent motif (PAM) complementary to the RNA guide. To obtain structural insight into the inner workings of Cpf1, the crystallization of an active complex containing the full extent of the crRNA and a 31-nucleotide dsDNA target was attempted. The gene encoding Cpf1 from Francisella novicida was cloned, overexpressed and purified. The crRNA was transcribed and purified in vitro. Finally, the ternary FnCpf1–crRNA–DNA complex was assembled and purified by preparative electrophoresis before crystallization. Crystals belonging to space group C2221, with unit-cell parameters a = 85.2, b = 137.6, c = 320.5 Å, were obtained and subjected to preliminary diffraction experiments. PMID:28695850

  13. Antitumor Activity of Osimertinib, an Irreversible Mutant-Selective EGFR Tyrosine Kinase Inhibitor, in NSCLC Harboring EGFR Exon 20 Insertions.

    PubMed

    Floc'h, Nicolas; Martin, Matthew J; Riess, Jonathan W; Orme, Jonathan P; Staniszewska, Anna D; Ménard, Ludovic; Cuomo, Maria Emanuela; O'Neill, Daniel J; Ward, Richard A; Finlay, M Raymond V; McKerrecher, Darren; Cheng, Mingshan; Vang, Daniel P; Burich, Rebekah A; Keck, James G; Gandara, David R; Mack, Philip C; Cross, Darren A E

    2018-05-01

    EGFR exon 20 insertions (Ex20Ins) account for 4% to 10% of EGFR activating mutations in non-small cell lung cancer (NSCLC). EGFR Ex20Ins tumors are generally unresponsive to first- and second-generation EGFR inhibitors, and current standard of care for NSCLC patients with EGFR Ex20Ins is conventional cytotoxic chemotherapy. Therefore, the development of an EGFR TKI that can more effectively target NSCLC with EGFR Ex20Ins mutations represents a major advance for this patient subset. Osimertinib is a third-generation EGFR TKI approved for the treatment of advanced NSCLC harboring EGFR T790M; however, the activity of osimertinib in EGFR Ex20Ins NSCLC has yet to be fully assessed. Using CRISPR-Cas 9 engineered cell lines carrying the most prevalent Ex20Ins mutations, namely Ex20Ins D770_N771InsSVD (22%) or Ex20Ins V769_D770InsASV (17%), and a series of patient-derived xenografts, we have characterized osimertinib and AZ5104 (a circulating metabolite of osimertinib) activities against NSCLC harboring Ex20Ins. We report that osimertinib and AZ5104 inhibit signaling pathways and cellular growth in Ex20Ins mutant cell lines in vitro and demonstrate sustained tumor growth inhibition of EGFR-mutant tumor xenograft harboring the most prevalent Ex20Ins in vivo The antitumor activity of osimertinib and AZ5104 in NSCLC harboring EGFR Ex20Ins is further described herein using a series of patient-derived xenograft models. Together these data support clinical testing of osimertinib in patients with EGFR Ex20Ins NSCLC. Mol Cancer Ther; 17(5); 885-96. ©2018 AACR . ©2018 American Association for Cancer Research.

  14. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Lobster Boat Race, Winter Harbor, ME. (a) Regulated area. The regulated area includes all waters of Winter...

  15. Endonuclease EEPD1 Is a Gatekeeper for Repair of Stressed Replication Forks*

    PubMed Central

    Kim, Hyun-Suk; Nickoloff, Jac A.; Wu, Yuehan; Williamson, Elizabeth A.; Sidhu, Gurjit Singh; Reinert, Brian L.; Jaiswal, Aruna S.; Srinivasan, Gayathri; Patel, Bhavita; Kong, Kimi; Burma, Sandeep; Lee, Suk-Hee; Hromas, Robert A.

    2017-01-01

    Replication is not as continuous as once thought, with DNA damage frequently stalling replication forks. Aberrant repair of stressed replication forks can result in cell death or genome instability and resulting transformation to malignancy. Stressed replication forks are most commonly repaired via homologous recombination (HR), which begins with 5′ end resection, mediated by exonuclease complexes, one of which contains Exo1. However, Exo1 requires free 5′-DNA ends upon which to act, and these are not commonly present in non-reversed stalled replication forks. To generate a free 5′ end, stalled replication forks must therefore be cleaved. Although several candidate endonucleases have been implicated in cleavage of stalled replication forks to permit end resection, the identity of such an endonuclease remains elusive. Here we show that the 5′-endonuclease EEPD1 cleaves replication forks at the junction between the lagging parental strand and the unreplicated DNA parental double strands. This cleavage creates the structure that Exo1 requires for 5′ end resection and HR initiation. We observed that EEPD1 and Exo1 interact constitutively, and Exo1 repairs stalled replication forks poorly without EEPD1. Thus, EEPD1 performs a gatekeeper function for replication fork repair by mediating the fork cleavage that permits initiation of HR-mediated repair and restart of stressed forks. PMID:28049724

  16. Production and characterization of recombinant protein preparations of Endonuclease G-homologs from yeast, C. elegans and humans.

    PubMed

    Kieper, Jana; Lauber, Christiane; Gimadutdinow, Oleg; Urbańska, Anna; Cymerman, Iwona; Ghosh, Mahua; Szczesny, Bartosz; Meiss, Gregor

    2010-09-01

    Nuc1p, CPS-6, EndoG and EXOG are evolutionary conserved mitochondrial nucleases from yeast, Caenorhabditis elegans and humans, respectively. These enzymes play an important role in programmed cell death as well as mitochondrial DNA-repair and recombination. Whereas a significant interest has been given to the cell biology of these proteins, in particular their recruitment during caspase-independent apoptosis, determination of their biochemical properties has lagged behind. In part, biochemical as well as structural analysis of mitochondrial nucleases has been hampered by the fact that upon cloning and overexpression in Escherichia coli these enzymes can exert considerable toxicity and tend to aggregate and form inclusion bodies. We have, therefore, established a uniform E. coli expression system allowing us to obtain these four evolutionary related nucleases in active form from the soluble as well as insoluble fractions of E. coli cell lysates. Using preparations of recombinant Nuc1p, CPS-6, EndoG and EXOG we have compared biochemical properties and the substrate specificities of these related nucleases on selected substrates in parallel. Whereas Nuc1p and EXOG in addition to their endonuclease activity exert 5'-3'-exonuclease activity, CPS-6 and EndoG predominantly are endonucleases. These findings allow speculating that the mechanisms of action of these related nucleases in cell death as well as DNA-repair and recombination differ according to their enzyme activities and substrate specificities. Copyright 2010 Elsevier Inc. All rights reserved.

  17. Double-stranded Endonuclease Activity in Bacillus halodurans Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated Cas2 Protein*

    PubMed Central

    Nam, Ki Hyun; Ding, Fran; Haitjema, Charles; Huang, Qingqiu; DeLisa, Matthew P.; Ke, Ailong

    2012-01-01

    The CRISPR (clustered regularly interspaced short palindromic repeats) system is a prokaryotic RNA-based adaptive immune system against extrachromosomal genetic elements. Cas2 is a universally conserved core CRISPR-associated protein required for the acquisition of new spacers for CRISPR adaptation. It was previously characterized as an endoribonuclease with preference for single-stranded (ss)RNA. Here, we show using crystallography, mutagenesis, and isothermal titration calorimetry that the Bacillus halodurans Cas2 (Bha_Cas2) from the subtype I-C/Dvulg CRISPR instead possesses metal-dependent endonuclease activity against double-stranded (ds)DNA. This activity is consistent with its putative function in producing new spacers for insertion into the 5′-end of the CRISPR locus. Mutagenesis and isothermal titration calorimetry studies revealed that a single divalent metal ion (Mg2+ or Mn2+), coordinated by a symmetric Asp pair in the Bha_Cas2 dimer, is involved in the catalysis. We envision that a pH-dependent conformational change switches Cas2 into a metal-binding competent conformation for catalysis. We further propose that the distinct substrate preferences among Cas2 proteins may be determined by the sequence and structure in the β1–α1 loop. PMID:22942283

  18. Effects of Dimerization of Serratia marcescens Endonuclease on Water Dynamics.

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

    Chen, Chuanying; Beck, Brian W.; Krause, Kurt

    2007-02-15

    The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. The dynamics and structure of Serratia marcescens endonuclease and its neighboring solvent are investigated by molecular dynamics (MD). Comparisons are made with structural and biochemical experiments. The dimer form is physiologic and functions more processively than the monomer. We previously found a channel formed by connected clusters of waters from the active site to the dimer interface. Here, we showmore » that dimerization clearly changes correlations in the water structure and dynamics in the active site not seen in the monomer. Our results indicate that water at the active sites of the dimer is less affected compared with bulk solvent than in the monomer where it has much slower characteristic relaxation times. Given that water is a required participant in the reaction, this gives a clear advantage to dimerization in the absence of an apparent ability to use both active sites simultaneously.« less

  19. Operation and Maintence, Vermilion Harbor, Erie County, Ohio.

    DTIC Science & Technology

    1976-03-01

    channel and structural maintenance activities at Vermilion Harbor. Although 6 ...- this alternative would eliminate temporary adverse ecological effects of...of dredging on water quality, aquatic ecology , and harbor recreation and related 4 businesses wbuld be reduced to a level commensurate with reduced...effects on aquatic ecology but would have long- term, beneficial effects on shoreline erosion and beach areas. There have been no specific requests from

  20. Apurinic/Apyrimidinic Endonuclease 1 Is the Essential Nuclease during Immunoglobulin Class Switch Recombination

    PubMed Central

    Masani, Shahnaz; Han, Li

    2013-01-01

    Immunoglobulin (Ig) class switch recombination (CSR) is initiated by activation-induced cytidine deaminase (AID) that catalyzes numerous DNA cytosine deaminations within switch regions. The resulting uracils are processed by uracil base excision and/or mismatch repair enzymes that ultimately generate switch region DNA double-strand breaks (DSBs). Uracil glycosylase 2 (UNG2) is required for CSR, most likely by removing uracils to generate abasic sites. Although it is presumed that the apurinic/apyrimidinic endonuclease 1 (APE1) generates DNA strand incisions (a prerequisite for CSR) at these abasic sites, a direct test of the requirement for APE1 in CSR has been difficult because of the embryonic lethality of APE1 ablation in mice. Here, we report the successful deletion of the APE1 gene in a mouse B cell line (CH12F3) capable of robust CSR in vitro. In contrast to the general assumption that APE1 is essential for cellular viability, deletion of APE1 in CH12F3 cells has no apparent effect on cell viability or growth. Moreover, CSR in APE1-null CH12F3 cells is drastically reduced, providing direct evidence for an essential role for APE1 in switch region cleavage and CSR. Finally, deletion of AP endonuclease 2 (APE2) has no effect on CSR in either APE1-proficient or -deficient cells. PMID:23382073

  1. Crystal structure of NucB, a biofilm-degrading endonuclease

    PubMed Central

    Baslé, Arnaud; Hewitt, Lorraine; Koh, Alan; Lamb, Heather K; Thompson, Paul; Burgess, J Grant; Hall, Michael J; Hawkins, Alastair R; Murray, Heath

    2018-01-01

    Abstract Bacterial biofilms are a complex architecture of cells that grow on moist interfaces, and are held together by a molecular glue of extracellular proteins, sugars and nucleic acids. Biofilms are particularly problematic in human healthcare as they can coat medical implants and are thus a potential source of disease. The enzymatic dispersal of biofilms is increasingly being developed as a new strategy to treat this problem. Here, we have characterized NucB, a biofilm-dispersing nuclease from a marine strain of Bacillus licheniformis, and present its crystal structure together with the biochemistry and a mutational analysis required to confirm its active site. Taken together, these data support the categorization of NucB into a unique subfamily of the ββα metal-dependent non-specific endonucleases. Understanding the structure and function of NucB will facilitate its future development into an anti-biofilm therapeutic agent. PMID:29165717

  2. 77 FR 50916 - Safety Zone; Boston Harbor's Rock Removal Project, Boston Inner Harbor, Boston, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2012-0767] RIN 1625-AA00 Safety Zone; Boston Harbor's Rock Removal Project, Boston Inner Harbor, Boston, MA AGENCY: Coast.... 165.T01-0767 Safety Zone; Boston Harbor's Rock Removal Project, Boston Inner Harbor, Boston, MA. (a...

  3. Restriction of a bacteriophage of Streptomyces albus G involving endonuclease SalI.

    PubMed Central

    Chater, K F; Wilde, L C

    1976-01-01

    The bacteriophage Pa16, isolated from soil on Streptomyces albus G, was restricted when transferred from an alternative host back to S. albus G. Extracted unmodified Pa16 deoxyribonucleic acid was cleaved at a single site by a cell-free extract of S. albus G. Fractions cleaving Pal6 deoxyribonucleic acid contained the endonuclease SalI first described by J. Arrand, P. Myers, and R. J. Roberts (unpublished data). A mutant of S. albus G was isolated which was defective in both restriction and modification of Pal6. This mutant lacked SalI activity. It is concluded that SalI is the agent of restriction of Pal6 by S. albus G. Images PMID:977549

  4. 33 CFR 125.15 - Access to waterfront facilities, and port and harbor areas, including vessels and harbor craft...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., and port and harbor areas, including vessels and harbor craft therein. 125.15 Section 125.15....15 Access to waterfront facilities, and port and harbor areas, including vessels and harbor craft....09 to those waterfront facilities, and port and harbor areas, including vessels and harbor craft...

  5. The Helicobacter pylori HpyAXII restriction–modification system limits exogenous DNA uptake by targeting GTAC sites but shows asymmetric conservation of the DNA methyltransferase and restriction endonuclease components

    PubMed Central

    Humbert, Olivier; Salama, Nina R.

    2008-01-01

    The naturally competent organism Helicobacter pylori encodes a large number of restriction–modification (R–M) systems that consist of a restriction endonuclease and a DNA methyltransferase. R–M systems are not only believed to limit DNA exchange among bacteria but may also have other cellular functions. We report a previously uncharacterized H. pylori type II R–M system, M.HpyAXII/R.HpyAXII. We show that this system targets GTAC sites, which are rare in the H. pylori chromosome but numerous in ribosomal RNA genes. As predicted, this type II R–M system showed attributes of a selfish element. Deletion of the methyltransferase M.HpyAXII is lethal when associated with an active endonuclease R.HpyAXII unless compensated by adaptive mutation or gene amplification. R.HpyAXII effectively restricted both unmethylated plasmid and chromosomal DNA during natural transformation and was predicted to belong to the novel ‘half pipe’ structural family of endonucleases. Analysis of a panel of clinical isolates revealed that R.HpyAXII was functional in a small number of H. pylori strains (18.9%, n = 37), whereas the activity of M.HpyAXII was highly conserved (92%, n = 50), suggesting that GTAC methylation confers a selective advantage to H. pylori. However, M.HpyAXII activity did not enhance H. pylori fitness during stomach colonization of a mouse infection model. PMID:18978016

  6. The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome

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

    Trego, Kelly S.; Chernikova, Sophia B.; Davalos, Albert R.

    XPG is a structure-specific endonuclease required for nucleotide excision repair (NER). XPG incision defects result in the cancer-prone syndrome xeroderma pigmentosum, whereas truncating mutations of XPG cause the severe postnatal progeroid developmental disorder Cockayne syndrome. We show that XPG interacts directly with WRN protein, which is defective in the premature aging disorder Werner syndrome, and that the two proteins undergo similar sub-nuclear redistribution in S-phase and co-localize in nuclear foci. The co-localization was observed in mid- to late-S-phase, when WRN moves from nucleoli to nuclear foci that have been shown to contain protein markers of both stalled replication forks andmore » telomeric proteins. We mapped the interaction between XPG and WRN to the C-terminal domains of each and show that interaction with the C-terminal domain of XPG strongly stimulates WRN helicase activity. WRN also possesses a competing DNA single-strand annealing activity that, combined with unwinding, has been shown to coordinate regression of model replication forks to form Holliday junction/chicken foot intermediate structures. We tested whether XPG stimulated WRN annealing activity and found that XPG itself has intrinsic strand annealing activity that requires the unstructured R- and C-terminal domains, but not the conserved catalytic core or endonuclease activity. Annealing by XPG is cooperative, rather than additive, with WRN annealing. Taken together, our results suggest a novel function for XPG in S-phase that is at least in part carried out coordinately with WRN, and which may contribute to the severity of the phenotypes that occur upon loss of XPG.« less

  7. Repair Rate of Clustered Abasic DNA Lesions by Human Endonuclease: Molecular Bases of Sequence Specificity.

    PubMed

    Gattuso, Hugo; Durand, Elodie; Bignon, Emmanuelle; Morell, Christophe; Georgakilas, Alexandros G; Dumont, Elise; Chipot, Christophe; Dehez, François; Monari, Antonio

    2016-10-06

    In the present contribution, the interaction between damaged DNA and repair enzymes is examined by means of molecular dynamics simulations. More specifically, we consider clustered abasic DNA lesions processed by the primary human apurinic/apyrimidinic (AP) endonuclease, APE1. Our results show that, in stark contrast with the corresponding bacterial endonucleases, human APE1 imposes strong geometrical constraints on the DNA duplex. As a consequence, the level of recognition and, hence, the repair rate is higher. Important features that guide the DNA/protein interactions are the presence of an extended positively charged region and of a molecular tweezers that strongly constrains DNA. Our results are on very good agreement with the experimentally determined repair rate of clustered abasic lesions. The lack of repair for one particular arrangement of the two abasic sites is also explained considering the peculiar destabilizing interaction between the recognition region and the second lesion, resulting in a partial opening of the molecular tweezers and, thus, a less stable complex. This contribution cogently establishes the molecular bases for the recognition and repair of clustered DNA lesions by means of human endonucleases.

  8. Evolutionary and biogeographical implications of degraded LAGLIDADG endonuclease functionality and group I intron occurrence in stony corals (Scleractinia) and mushroom corals (Corallimorpharia).

    PubMed

    Celis, Juan Sebastián; Edgell, David R; Stelbrink, Björn; Wibberg, Daniel; Hauffe, Torsten; Blom, Jochen; Kalinowski, Jörn; Wilke, Thomas

    2017-01-01

    Group I introns and homing endonuclease genes (HEGs) are mobile genetic elements, capable of invading target sequences in intron-less genomes. LAGLIDADG HEGs are the largest family of endonucleases, playing a key role in the mobility of group I introns in a process known as 'homing'. Group I introns and HEGs are rare in metazoans, and can be mainly found inserted in the COXI gene of some sponges and cnidarians, including stony corals (Scleractinia) and mushroom corals (Corallimorpharia). Vertical and horizontal intron transfer mechanisms have been proposed as explanations for intron occurrence in cnidarians. However, the central role of LAGLIDADG motifs in intron mobility mechanisms remains poorly understood. To resolve questions regarding the evolutionary origin and distribution of group I introns and HEGs in Scleractinia and Corallimorpharia, we examined intron/HEGs sequences within a comprehensive phylogenetic framework. Analyses of LAGLIDADG motif conservation showed a high degree of degradation in complex Scleractinia and Corallimorpharia. Moreover, the two motifs lack the respective acidic residues necessary for metal-ion binding and catalysis, potentially impairing horizontal intron mobility. In contrast, both motifs are highly conserved within robust Scleractinia, indicating a fully functional endonuclease capable of promoting horizontal intron transference. A higher rate of non-synonymous substitutions (Ka) detected in the HEGs of complex Scleractinia and Corallimorpharia suggests degradation of the HEG, whereas lower Ka rates in robust Scleractinia are consistent with a scenario of purifying selection. Molecular-clock analyses and ancestral inference of intron type indicated an earlier intron insertion in complex Scleractinia and Corallimorpharia in comparison to robust Scleractinia. These findings suggest that the lack of horizontal intron transfers in the former two groups is related to an age-dependent degradation of the endonuclease activity. Moreover

  9. The Methanothermobacter thermautotrophicus ExoIII homologue Mth212 is a DNA uridine endonuclease

    PubMed Central

    Georg, Jens; Schomacher, Lars; Chong, James P. J.; Majerník, Alan I.; Raabe, Monika; Urlaub, Henning; Müller, Sabine; Ciirdaeva, Elena; Kramer, Wilfried; Fritz, Hans-Joachim

    2006-01-01

    The genome of Methanothermobacter thermautotrophicus, as a hitherto unique case, is apparently devoid of genes coding for general uracil DNA glycosylases, the universal mediators of base excision repair following hydrolytic deamination of DNA cytosine residues. We have now identified protein Mth212, a member of the ExoIII family of nucleases, as a possible initiator of DNA uracil repair in this organism. This enzyme, in addition to bearing all the enzymological hallmarks of an ExoIII homologue, is a DNA uridine endonuclease (U-endo) that nicks double-stranded DNA at the 5′-side of a 2′-d-uridine residue, irrespective of the nature of the opposing nucleotide. This type of activity has not been described before; it is absent from the ExoIII homologues of Escherichia coli, Homo sapiens and Methanosarcina mazei, all of which are equipped with uracil DNA repair glycosylases. The U-endo activity of Mth212 is served by the same catalytic center as its AP-endo activity. PMID:17012282

  10. Geochemical evaluation of the land use and human activities at a Medieval harbor site, Masuda city, Shimane Prefecture, Japan

    NASA Astrophysics Data System (ADS)

    Dalai, Banzragch; Ishiga, Hiroaki

    2014-05-01

    Large-scale harbor and settlement sites from the latter half of the eleventh through sixteenth centuries have recently been discovered in the northern part of Masuda City, Shimane Prefecture, Japan. The sites were constructed at the river mouth delta of the Takatsu and Masuda rivers, facing the Sea of Japan. In former time, the mouths of the two rivers are thought to have formed a shallow lagoon connecting with the Sea of Japan. The harbor was thus well located for ships sailing along the sea coast, especially for conducting trade with the China mainland and the Korean peninsula. Archaeological investigations have identified over 800 construction pits, blacksmith hearths, harbor structures and numerous fragments of ceramic porcelain originating both from within Japan and from Asia (China, Korea, Vietnam and Thailand). It seems that the maritime trade network operated from this Medieval harbor site by the Masuda Clan was on an East Asian scale. Consequently, the harbor site can be expected to have received a considerable amount of ancient anthropogenic matter. Concentrations of 22 elements in 66 soil samples from the Nakazu Higashihara site were determined by X-ray fluorescence spectroscopy, in order to identify the land use and human impacts on soil chemistry at the harbor site. The results show that significant differences in geochemical compositional exist between the northern and southern parts of the site due to differences in lithology and land use practice. The south area was a production area of this harbor site. Three different activity areas were recognized within this area (fire pit and charcoal area, building pillars, and a blacksmith furnace area), based on geochemical and archaeological information. Cluster analysis shows a strong relationship exists between As, Pb, Cu, Br, TS, MnO and P2O5 in the fire pit and charcoal area. These charcoal materials were likely derived from fuel used in firing and heating. Close relationships occur between Cr, Sr, Sc

  11. Purification and characterization of the restriction endonuclease RsrI, an isoschizomer of EcoRI.

    PubMed

    Greene, P J; Ballard, B T; Stephenson, F; Kohr, W J; Rodriguez, H; Rosenberg, J M; Boyer, H W

    1988-08-15

    Rhodobacter sphaeroides strain 630 produces restriction enzyme RsrI which is an isoschizomer of EcoRI. We have purified this enzyme and initiated a comparison with the EcoRI endonuclease. The properties of RsrI are consistent with a reaction mechanism similar to that of EcoRI: the position of cleavage within the -GAATTC-site is identical, the MgCl2 optimum for the cleavage is identical, and the pH profile is similar. Methylation of the substrate sequence by the EcoRI methylase protects the site from cleavage by the RsrI endonuclease. RsrI cross-reacts strongly with anti-EcoRI serum indicating three-dimensional structural similarities. We have determined the sequence of 34 N terminal amino acids for RsrI and this sequence possesses significant similarity to the EcoRI N terminus.

  12. Activating health goals reduces (increases) hedonic evaluation of food brands for people who harbor highly positive (negative) affect toward them.

    PubMed

    Connell, Paul M; Mayor, Lauren F

    2013-06-01

    Associations of pleasure and fun with junk foods have the potential to create considerable challenges for efforts to improve diets. The aim of this research was to determine whether activating health goals had the potential to exploit mixed motivations (i.e., health and pleasure) that people have related to food, and subsequently strip junk foods of the expected pleasure derived from them. In study 1, 98 participants evaluated a soft drink brand after being primed (not primed) for health. In study 2, 93 participants evaluated a presweetened breakfast cereal brand after being primed (not primed) for health. In both studies, participants who harbored highly positive feelings for the food brands devalued their hedonic judgments of them when they were primed for health. However, in an unexpected result, participants in both studies who harbored highly negative feelings for the food brands revalued their hedonic judgments of them (i.e., increased the favorability) when they were primed for health. Thus, increasing health salience is only effective in decreasing expected pleasure derived from junk foods for people who harbor positive affect toward junk food brands, and is likely counterproductive for people who harbor negative affect toward junk food brands. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Comparative Structural and Functional Analysis of Bunyavirus and Arenavirus Cap-Snatching Endonucleases

    PubMed Central

    Reguera, Juan; Gerlach, Piotr; Rosenthal, Maria; Gaudon, Stephanie; Coscia, Francesca; Günther, Stephan; Cusack, Stephen

    2016-01-01

    Segmented negative strand RNA viruses of the arena-, bunya- and orthomyxovirus families uniquely carry out viral mRNA transcription by the cap-snatching mechanism. This involves cleavage of host mRNAs close to their capped 5′ end by an endonuclease (EN) domain located in the N-terminal region of the viral polymerase. We present the structure of the cap-snatching EN of Hantaan virus, a bunyavirus belonging to hantavirus genus. Hantaan EN has an active site configuration, including a metal co-ordinating histidine, and nuclease activity similar to the previously reported La Crosse virus and Influenza virus ENs (orthobunyavirus and orthomyxovirus respectively), but is more active in cleaving a double stranded RNA substrate. In contrast, Lassa arenavirus EN has only acidic metal co-ordinating residues. We present three high resolution structures of Lassa virus EN with different bound ion configurations and show in comparative biophysical and biochemical experiments with Hantaan, La Crosse and influenza ENs that the isolated Lassa EN is essentially inactive. The results are discussed in the light of EN activation mechanisms revealed by recent structures of full-length influenza virus polymerase. PMID:27304209

  14. A detailed experimental study of a DNA computer with two endonucleases.

    PubMed

    Sakowski, Sebastian; Krasiński, Tadeusz; Sarnik, Joanna; Blasiak, Janusz; Waldmajer, Jacek; Poplawski, Tomasz

    2017-07-14

    Great advances in biotechnology have allowed the construction of a computer from DNA. One of the proposed solutions is a biomolecular finite automaton, a simple two-state DNA computer without memory, which was presented by Ehud Shapiro's group at the Weizmann Institute of Science. The main problem with this computer, in which biomolecules carry out logical operations, is its complexity - increasing the number of states of biomolecular automata. In this study, we constructed (in laboratory conditions) a six-state DNA computer that uses two endonucleases (e.g. AcuI and BbvI) and a ligase. We have presented a detailed experimental verification of its feasibility. We described the effect of the number of states, the length of input data, and the nondeterminism on the computing process. We also tested different automata (with three, four, and six states) running on various accepted input words of different lengths such as ab, aab, aaab, ababa, and of an unaccepted word ba. Moreover, this article presents the reaction optimization and the methods of eliminating certain biochemical problems occurring in the implementation of a biomolecular DNA automaton based on two endonucleases.

  15. Unusual target site disruption by the rare-cutting HNH restriction endonuclease PacI

    PubMed Central

    Shen, Betty; Heiter, Daniel F.; Chan, Siu-Hong; Wang, Hua; Xu, Shuang-Yong; Morgan, Richard D.; Wilson, Geoffrey G.; Stoddard, Barry L.

    2010-01-01

    The crystal structure of the rare-cutting HNH restriction endonuclease PacI in complex with its eight base pair target recognition sequence 5'-TTAATTAA-3' has been determined to 1.9 Å resolution. The enzyme forms an extended homodimer, with each subunit containing two zinc-bound motifs surrounding a ββα-metal catalytic site. The latter is unusual in that a tyrosine residue likely initiates strand-cleavage. PacI dramatically distorts its target sequence from Watson-Crick duplex DNA basepairing, with every base separated from its original partner. Two bases on each strand are unpaired, four are engaged in non-canonical A:A and T:T base pairs, and the remaining two bases are matched with new Watson-Crick partners. This represents a highly unusual DNA binding mechanism for a restriction endonuclease, and implies that initial recognition of the target site might involve significantly different contacts from those visualized in the DNA-bound cocrystal structures. PMID:20541511

  16. 33 CFR 165.904 - Lake Michigan at Chicago Harbor & Burnham Park Harbor-Safety and Security Zone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Harbor, to the northwest point. (b) Effective times and dates. This safety and security zone will be in... & Burnham Park Harbor-Safety and Security Zone. 165.904 Section 165.904 Navigation and Navigable Waters... Guard District § 165.904 Lake Michigan at Chicago Harbor & Burnham Park Harbor—Safety and Security Zone...

  17. A geochemical and sedimentological perspective of the life cycle of Neapolis harbor (Naples, southern Italy)

    NASA Astrophysics Data System (ADS)

    Delile, H.; Goiran, J.-P.; Blichert-Toft, J.; Arnaud-Godet, F.; Romano, P.; Bravard, J.-P.

    2016-10-01

    Since the discovery of the ancient harbor of Naples in 2004 during construction work on an underground railway, geoarchaeological studies undertaken on the archaeological excavation have revealed the main stratigraphic and paleo-environmental levels of the harbor site near the Piazza Municipio. However, knowledge of the dynamics and paleo-environmental changes in the water column of the harbor, as well as the processes of transport and deposition of sediments that led to siltation and infilling of the harbor basin, has been lacking due to the absence of high-resolution data. To fill these gaps, we have undertaken a three-dimensional study (longitudinal, transverse and vertical) of the harbor deposits by carrying out geochemical and sedimentological analyses of four stratigraphic sections of the archaeological excavation. The results show that after a phase of relative calm during the first half of the 1st c. AD, siltation of the harbor progressed exponentially up to the 5th c. AD, when dredging operations were carried out to obtain a water level sufficient for the development of maritime and harbor activities. We attribute this acceleration of siltation to a combination of climatic, anthropic and volcanic factors. Volcanic activity was responsible for a high-energy, tsunami-type event during the eruption of Vesuvius in 79 AD. From the 5th c. AD onwards, the harbor basin of Neapolis does not appear to have been functional as evidenced by its transformation into a lagoon following coastal progradation. The last stage of infilling was the development of a flood-dominated fan delta under the combined influences of climatic cooling in the Early Medieval Cool Period and agro-pastoral activities in the catchment area of the harbor. Several generations of paleo-channels, containing flash flood deposits, as well as sheet wash from sheet floods, are indicative of high environmental instability in this period.

  18. Genomic Disruption of VEGF-A Expression in Human Retinal Pigment Epithelial Cells Using CRISPR-Cas9 Endonuclease.

    PubMed

    Yiu, Glenn; Tieu, Eric; Nguyen, Anthony T; Wong, Brittany; Smit-McBride, Zeljka

    2016-10-01

    To employ type II clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 endonuclease to suppress ocular angiogenesis by genomic disruption of VEGF-A in human RPE cells. CRISPR sequences targeting exon 1 of human VEGF-A were computationally identified based on predicted Cas9 on- and off-target probabilities. Single guide RNA (gRNA) cassettes with these target sequences were cloned into lentiviral vectors encoding the Streptococcuspyogenes Cas9 endonuclease (SpCas9) gene. The lentiviral vectors were used to infect ARPE-19 cells, a human RPE cell line. Frequency of insertion or deletion (indel) mutations was assessed by T7 endonuclease 1 mismatch detection assay; mRNA levels were assessed with quantitative real-time PCR; and VEGF-A protein levels were determined by ELISA. In vitro angiogenesis was measured using an endothelial cell tube formation assay. Five gRNAs targeting VEGF-A were selected based on the highest predicted on-target probabilities, lowest off-target probabilities, or combined average of both scores. Lentiviral delivery of the top-scoring gRNAs with SpCas9 resulted in indel formation in the VEGF-A gene at frequencies up to 37.0% ± 4.0% with corresponding decreases in secreted VEGF-A protein up to 41.2% ± 7.4% (P < 0.001), and reduction of endothelial tube formation up to 39.4% ± 9.8% (P = 0.02). No significant indel formation in the top three putative off-target sites tested was detected. The CRISPR-Cas9 endonuclease system may reduce VEGF-A secretion from human RPE cells and suppress angiogenesis, supporting the possibility of employing gene editing for antiangiogenesis therapy in ocular diseases.

  19. Acquired Resistance Mechanisms to Combination Met-TKI/EGFR-TKI Exposure in Met-Amplified EGFR-TKI-Resistant Lung Adenocarcinoma Harboring an Activating EGFR Mutation.

    PubMed

    Yamaoka, Toshimitsu; Ohmori, Tohru; Ohba, Motoi; Arata, Satoru; Kishino, Yasunari; Murata, Yasunori; Kusumoto, Sojiro; Ishida, Hiroo; Shirai, Takao; Hirose, Takashi; Ohnishi, Tsukasa; Sasaki, Yasutsuna

    2016-12-01

    Met-amplified EGFR-tyrosine kinase inhibitor (TKI)-resistant non-small cell lung cancer (NSCLC) harboring an activating EGFR mutation is responsive to concurrent EGFR-TKI and Met-TKI treatment in a preclinical model. Here, we determined that Met-amplified gefitinib-resistant cells acquire dual resistance to inhibition of EGFR and Met tyrosine kinase activities. PC-9 lung adenocarcinoma cells harboring 15-bp deletions (Del E746_A750) in EGFR exon 19 were treated with increasing concentrations of the Met-TKI PHA665752 and 1 μmol/L gefitinib for 1 year; three resistant clones were established via Met amplification. The three dual-resistance cell lines (PC-9DR2, PC-9DR4, and PC-9DR6, designated as DR2, DR4, and DR6, respectively) exhibited different mechanisms for evading both EGFR and Met inhibition. None of the clones harbored a secondary mutation of EGFR T790M or a Met mutation. Insulin-like growth factor (IGF)/IGF1 receptor activation in DR2 and DR4 cells acted as a bypass signaling pathway. Met expression was attenuated to a greater extent in DR2 than in PC-9 cells, but was maintained in DR4 cells by overexpression of IGF-binding protein 3. In DR6 cells, Met was further amplified by association with HSP90, which protected Met from degradation and induced SET and MYND domain-containing 3 (SMYD3)-mediated Met transcription. This is the first report describing the acquisition of dual resistance mechanisms in NSCLC harboring an activating EGFR mutation to Met-TKI and EGFR-TKI following previous EGFR-TKI treatment. These results might inform the development of more effective therapeutic strategies for NSCLC treatment. Mol Cancer Ther; 15(12); 3040-54. ©2016 AACR. ©2016 American Association for Cancer Research.

  20. A unique dual recognition hairpin probe mediated fluorescence amplification method for sensitive detection of uracil-DNA glycosylase and endonuclease IV activities.

    PubMed

    Wu, Yushu; Yan, Ping; Xu, Xiaowen; Jiang, Wei

    2016-03-07

    Uracil-DNA glycosylase (UDG) and endonuclease IV (Endo IV) play cooperative roles in uracil base-excision repair (UBER) and inactivity of either will interrupt the UBER to cause disease. Detection of UDG and Endo IV activities is crucial to evaluate the UBER process in fundamental research and diagnostic application. Here, a unique dual recognition hairpin probe mediated fluorescence amplification method was developed for sensitively and selectively detecting UDG and Endo IV activities. For detecting UDG activity, the uracil base in the probe was excised by the target enzyme to generate an apurinic/apyrimidinic (AP) site, achieving the UDG recognition. Then, the AP site was cleaved by a tool enzyme Endo IV, releasing a primer to trigger rolling circle amplification (RCA) reaction. Finally, the RCA reaction produced numerous repeated G-quadruplex sequences, which interacted with N-methyl-mesoporphyrin IX to generate an enhanced fluorescence signal. Alternatively, for detecting Endo IV activity, the uracil base in the probe was first converted into an AP site by a tool enzyme UDG. Next, the AP site was cleaved by the target enzyme, achieving the Endo IV recognition. The signal was then generated and amplified in the same way as those in the UDG activity assay. The detection limits were as low as 0.00017 U mL(-1) for UDG and 0.11 U mL(-1) for Endo IV, respectively. Moreover, UDG and Endo IV can be well distinguished from their analogs. This method is beneficial for properly evaluating the UBER process in function studies and disease prognoses.

  1. Diverse Small Molecule Inhibitors of Human Apurinic/Apyrimidinic Endonuclease APE1 Identified from a Screen of a Large Public Collection

    PubMed Central

    Dorjsuren, Dorjbal; Kim, Daemyung; Vyjayanti, Vaddadi N.; Maloney, David J.; Jadhav, Ajit; Wilson, David M.; Simeonov, Anton

    2012-01-01

    The major human apurinic/apyrimidinic endonuclease APE1 plays a pivotal role in the repair of base damage via participation in the DNA base excision repair (BER) pathway. Increased activity of APE1, often observed in tumor cells, is thought to contribute to resistance to various anticancer drugs, whereas down-regulation of APE1 sensitizes cells to DNA damaging agents. Thus, inhibiting APE1 repair endonuclease function in cancer cells is considered a promising strategy to overcome therapeutic agent resistance. Despite ongoing efforts, inhibitors of APE1 with adequate drug-like properties have yet to be discovered. Using a kinetic fluorescence assay, we conducted a fully-automated high-throughput screen (HTS) of the NIH Molecular Libraries Small Molecule Repository (MLSMR), as well as additional public collections, with each compound tested as a 7-concentration series in a 4 µL reaction volume. Actives identified from the screen were subjected to a panel of confirmatory and counterscreen tests. Several active molecules were identified that inhibited APE1 in two independent assay formats and exhibited potentiation of the genotoxic effect of methyl methanesulfonate with a concomitant increase in AP sites, a hallmark of intracellular APE1 inhibition; a number of these chemotypes could be good starting points for further medicinal chemistry optimization. To our knowledge, this represents the largest-scale HTS to identify inhibitors of APE1, and provides a key first step in the development of novel agents targeting BER for cancer treatment. PMID:23110144

  2. Diverse small molecule inhibitors of human apurinic/apyrimidinic endonuclease APE1 identified from a screen of a large public collection.

    PubMed

    Dorjsuren, Dorjbal; Kim, Daemyung; Vyjayanti, Vaddadi N; Maloney, David J; Jadhav, Ajit; Wilson, David M; Simeonov, Anton

    2012-01-01

    The major human apurinic/apyrimidinic endonuclease APE1 plays a pivotal role in the repair of base damage via participation in the DNA base excision repair (BER) pathway. Increased activity of APE1, often observed in tumor cells, is thought to contribute to resistance to various anticancer drugs, whereas down-regulation of APE1 sensitizes cells to DNA damaging agents. Thus, inhibiting APE1 repair endonuclease function in cancer cells is considered a promising strategy to overcome therapeutic agent resistance. Despite ongoing efforts, inhibitors of APE1 with adequate drug-like properties have yet to be discovered. Using a kinetic fluorescence assay, we conducted a fully-automated high-throughput screen (HTS) of the NIH Molecular Libraries Small Molecule Repository (MLSMR), as well as additional public collections, with each compound tested as a 7-concentration series in a 4 µL reaction volume. Actives identified from the screen were subjected to a panel of confirmatory and counterscreen tests. Several active molecules were identified that inhibited APE1 in two independent assay formats and exhibited potentiation of the genotoxic effect of methyl methanesulfonate with a concomitant increase in AP sites, a hallmark of intracellular APE1 inhibition; a number of these chemotypes could be good starting points for further medicinal chemistry optimization. To our knowledge, this represents the largest-scale HTS to identify inhibitors of APE1, and provides a key first step in the development of novel agents targeting BER for cancer treatment.

  3. Homing endonuclease genes: the rise and fall and rise again of a selfish element.

    PubMed

    Burt, Austin; Koufopanou, Vassiliki

    2004-12-01

    Homing endonuclease genes (HEGs) are selfish genetic elements that spread by first cleaving chromosomes that do not contain them and then getting copied across to the broken chromosome as a byproduct of the repair process. The success of this strategy will depend on the opportunities for homing--in other words, the frequency with which HEG(+) and HEG(-) chromosomes come into contact--which varies widely among host taxa. HEGs are also unusual in that the selection pressure for endonuclease function disappears if they become fixed in a population, which makes them susceptible to degeneration and imposes a need for regular horizontal transmission between species. HEGs will be selected to reduce the harm done to the host organism, and this is expected to influence the evolution of their sequence specificity and maturase functions. HEGs may also be domesticated by their hosts, and are currently being put to human uses.

  4. Structural, functional and evolutionary relationships between homing endonucleases and proteins from their host organisms

    PubMed Central

    Taylor, Gregory K.; Stoddard, Barry L.

    2012-01-01

    Homing endonucleases (HEs) are highly specific DNA-cleaving enzymes that are encoded by invasive DNA elements (usually mobile introns or inteins) within the genomes of phage, bacteria, archea, protista and eukaryotic organelles. Six unique structural HE families, that collectively span four distinct nuclease catalytic motifs, have been characterized to date. Members of each family display structural homology and functional relationships to a wide variety of proteins from various organisms. The biological functions of those proteins are highly disparate and include non-specific DNA-degradation enzymes, restriction endonucleases, DNA-repair enzymes, resolvases, intron splicing factors and transcription factors. These relationships suggest that modern day HEs share common ancestors with proteins involved in genome fidelity, maintenance and gene expression. This review summarizes the results of structural studies of HEs and corresponding proteins from host organisms that have illustrated the manner in which these factors are related. PMID:22406833

  5. Structure and dynamics of mesophilic variants from the homing endonuclease I-DmoI

    NASA Astrophysics Data System (ADS)

    Alba, Josephine; Marcaida, Maria Jose; Prieto, Jesus; Montoya, Guillermo; Molina, Rafael; D'Abramo, Marco

    2017-12-01

    I-DmoI, from the hyperthermophilic archaeon Desulfurococcus mobilis, belongs to the LAGLIDADG homing endonuclease protein family. Its members are highly specific enzymes capable of recognizing long DNA target sequences, thus providing potential tools for genome manipulation. Working towards this particular application, many efforts have been made to generate mesophilic variants of I-DmoI that function at lower temperatures than the wild-type. Here, we report a structural and computational analysis of two I-DmoI mesophilic mutants. Despite very limited structural variations between the crystal structures of these variants and the wild-type, a different dynamical behaviour near the cleavage sites is observed. In particular, both the dynamics of the water molecules and the protein perturbation effect on the cleavage site correlate well with the changes observed in the experimental enzymatic activity.

  6. The RNA-induced silencing complex is a Mg2+-dependent endonuclease.

    PubMed

    Schwarz, Dianne S; Tomari, Yukihide; Zamore, Phillip D

    2004-05-04

    In the Drosophila and mammalian RNA interference (RNAi) pathways, target RNA destruction is catalyzed by the siRNA-guided, RNA-induced silencing complex (RISC). RISC has been proposed to be an siRNA-directed endonuclease, catalyzing cleavage of a single phosphodiester bond on the RNA target. Although 5' cleavage products are readily detected for RNAi in vitro, only 3' cleavage products have been observed in vivo. Proof that RISC acts as an endonuclease requires detection of both 5' and 3' cleavage products in a single experimental system. Here, we show that siRNA-programmed RISC generates both 5' and 3' cleavage products in vitro; cleavage requires Mg(2+), but not Ca(2+), and the cleavage product termini suggest a role for Mg(2+) in catalysis. Moreover, a single phosphorothioate in place of the scissile phosphate blocks cleavage; the phosphorothioate effect can be rescued by the thiophilic cation Mn(2+), but not by Ca(2+) or Mg(2+). We propose that during catalysis, a Mg(2+) ion is bound to the RNA substrate through a nonbridging oxygen of the scissile phosphate. The mechanism of endonucleolytic cleavage is not consistent with the mechanisms of the previously identified RISC nuclease, Tudor-SN. Thus, the RISC-component that mediates endonucleolytic cleavage of the target RNA remains to be identified.

  7. 75 FR 78601 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-16

    ... Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor Navigation Canal, New Orleans, Orleans Parish, LA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from... Harvey Lock), at New Orleans, Orleans Parish, Louisiana. This deviation is necessary to adjust the...

  8. Characterization of Arabidopsis thaliana mismatch specific endonucleases: application to mutation discovery by TILLING in pea.

    PubMed

    Triques, Karine; Sturbois, Bénédicte; Gallais, Stéphane; Dalmais, Marion; Chauvin, Stéphanie; Clepet, Christian; Aubourg, Sébastien; Rameau, Catherine; Caboche, Michel; Bendahmane, Abdelhafid

    2007-09-01

    Scanning DNA sequences for mutations and polymorphisms has become one of the most challenging, often expensive and time-consuming obstacles in many molecular genetic applications, including reverse genetic and clinical diagnostic applications. Enzymatic mutation detection methods are based on the cleavage of heteroduplex DNA at the mismatch sites. These methods are often limited by the availability of a mismatch-specific endonuclease, their sensitivity in detecting one allele in a pool of DNA and their costs. Here, we present detailed biochemical analysis of five Arabidopsis putative mismatch-specific endonucleases. One of them, ENDO1, is presented as the first endonuclease that recognizes and cleaves all types of mismatches with high efficiency. We report on a very simple protocol for the expression and purification of ENDO1. The ENDO1 system could be exploited in a wide range of mutation diagnostic tools. In particular, we report the use of ENDO1 for discovery of point mutations in the gibberellin 3beta-hydrolase gene of Pisum sativum. Twenty-one independent mutants were isolated, five of these were characterized and two new mutations affecting internodes length were identified. To further evaluate the quality of the mutant population we screened for mutations in four other genes and identified 5-21 new alleles per target. Based on the frequency of the obtained alleles we concluded that the pea population described here would be suitable for use in a large reverse-genetics project.

  9. DNA interrogation by the CRISPR RNA-guided endonuclease Cas9.

    PubMed

    Sternberg, Samuel H; Redding, Sy; Jinek, Martin; Greene, Eric C; Doudna, Jennifer A

    2014-03-06

    The clustered regularly interspaced short palindromic repeats (CRISPR)-associated enzyme Cas9 is an RNA-guided endonuclease that uses RNA-DNA base-pairing to target foreign DNA in bacteria. Cas9-guide RNA complexes are also effective genome engineering agents in animals and plants. Here we use single-molecule and bulk biochemical experiments to determine how Cas9-RNA interrogates DNA to find specific cleavage sites. We show that both binding and cleavage of DNA by Cas9-RNA require recognition of a short trinucleotide protospacer adjacent motif (PAM). Non-target DNA binding affinity scales with PAM density, and sequences fully complementary to the guide RNA but lacking a nearby PAM are ignored by Cas9-RNA. Competition assays provide evidence that DNA strand separation and RNA-DNA heteroduplex formation initiate at the PAM and proceed directionally towards the distal end of the target sequence. Furthermore, PAM interactions trigger Cas9 catalytic activity. These results reveal how Cas9 uses PAM recognition to quickly identify potential target sites while scanning large DNA molecules, and to regulate scission of double-stranded DNA.

  10. DNA interrogation by the CRISPR RNA-guided endonuclease Cas9

    NASA Astrophysics Data System (ADS)

    Sternberg, Samuel H.; Redding, Sy; Jinek, Martin; Greene, Eric C.; Doudna, Jennifer A.

    2014-03-01

    The clustered regularly interspaced short palindromic repeats (CRISPR)-associated enzyme Cas9 is an RNA-guided endonuclease that uses RNA-DNA base-pairing to target foreign DNA in bacteria. Cas9-guide RNA complexes are also effective genome engineering agents in animals and plants. Here we use single-molecule and bulk biochemical experiments to determine how Cas9-RNA interrogates DNA to find specific cleavage sites. We show that both binding and cleavage of DNA by Cas9-RNA require recognition of a short trinucleotide protospacer adjacent motif (PAM). Non-target DNA binding affinity scales with PAM density, and sequences fully complementary to the guide RNA but lacking a nearby PAM are ignored by Cas9-RNA. Competition assays provide evidence that DNA strand separation and RNA-DNA heteroduplex formation initiate at the PAM and proceed directionally towards the distal end of the target sequence. Furthermore, PAM interactions trigger Cas9 catalytic activity. These results reveal how Cas9 uses PAM recognition to quickly identify potential target sites while scanning large DNA molecules, and to regulate scission of double-stranded DNA.

  11. Restriction endonuclease analysis of chloroplast DNA in interspecies somatic Hybrids of Petunia.

    PubMed

    Kumar, A; Cocking, E C; Bovenberg, W A; Kool, A J

    1982-12-01

    Restriction endonuclease cleavage pattern analysis of chloroplast DNA (cpDNA) of three different interspecific somatic hybrid plants revealed that the cytoplasms of the hybrids contained only cpDNA of P. parodii. The somatic hybrid plants analysed were those between P. parodii (wild type) + P. hybrida (wild type); P. parodii (wild type)+P. inflata (cytoplasmic albino mutant); P. parodii (wild type) + P. parviflora (nuclear albino mutant). The presence of only P. parodii chloroplasts in the somatic hybrid of P. parodii + P. inflata is possibly due to the stringent selection used for somatic hybrid production. However, in the case of the two other somatic hybrids P. parodii + P. hybrida and P. parodii + P. parviflora it was not possible to determine whether the presence of only P. parodii chloroplasts in these somatic hybrid plants was due to the nature of the selection schemes used or simply occurred by chance. The relevance of such somatic hybrid material for the study of genomic-cytoplasmic interaction is discussed, as well as the use of restriction endonuclease fragment patterns for the analysis of taxonomic and evolutionary inter-relationships in the genus Petunia.

  12. 33 CFR 165.904 - Lake Michigan at Chicago Harbor & Burnham Park Harbor-Safety and Security Zone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... & Burnham Park Harbor-Safety and Security Zone. 165.904 Section 165.904 Navigation and Navigable Waters... Guard District § 165.904 Lake Michigan at Chicago Harbor & Burnham Park Harbor—Safety and Security Zone... entrance of the harbor connecting coordinates 41°51′09″ N, 087°36′36″W and 41°51′11″ N, 087°36′22″ W. (b...

  13. 33 CFR 165.904 - Lake Michigan at Chicago Harbor & Burnham Park Harbor-Safety and Security Zone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... & Burnham Park Harbor-Safety and Security Zone. 165.904 Section 165.904 Navigation and Navigable Waters... Guard District § 165.904 Lake Michigan at Chicago Harbor & Burnham Park Harbor—Safety and Security Zone... entrance of the harbor connecting coordinates 41°51′09″ N, 087°36′36″ W and 41°51′11″ N, 087°36′22″ W. (b...

  14. 33 CFR 165.904 - Lake Michigan at Chicago Harbor & Burnham Park Harbor-Safety and Security Zone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... & Burnham Park Harbor-Safety and Security Zone. 165.904 Section 165.904 Navigation and Navigable Waters... Guard District § 165.904 Lake Michigan at Chicago Harbor & Burnham Park Harbor—Safety and Security Zone... entrance of the harbor connecting coordinates 41°51′09″ N, 087°36′36″W and 41°51′11″ N, 087°36′22″ W. (b...

  15. Determinants for DNA target structure selectivity of the human LINE-1 retrotransposon endonuclease.

    PubMed

    Repanas, Kostas; Zingler, Nora; Layer, Liliana E; Schumann, Gerald G; Perrakis, Anastassis; Weichenrieder, Oliver

    2007-01-01

    The human LINE-1 endonuclease (L1-EN) is the targeting endonuclease encoded by the human LINE-1 (L1) retrotransposon. L1-EN guides the genomic integration of new L1 and Alu elements that presently account for approximately 28% of the human genome. L1-EN bears considerable technological interest, because its target selectivity may ultimately be engineered to allow the site-specific integration of DNA into defined genomic locations. Based on the crystal structure, we generated L1-EN mutants to analyze and manipulate DNA target site recognition. Crystal structures and their dynamic and functional analysis show entire loop grafts to be feasible, resulting in altered specificity, while individual point mutations do not change the nicking pattern of L1-EN. Structural parameters of the DNA target seem more important for recognition than the nucleotide sequence, and nicking profiles on DNA oligonucleotides in vitro are less well defined than the respective integration site consensus in vivo. This suggests that additional factors other than the DNA nicking specificity of L1-EN contribute to the targeted integration of non-LTR retrotransposons.

  16. Epigenetic Segregation of Microbial Genomes from Complex Samples Using Restriction Endonucleases HpaII and McrB.

    PubMed

    Liu, Guohong; Weston, Christopher Q; Pham, Long K; Waltz, Shannon; Barnes, Helen; King, Paula; Sphar, Dan; Yamamoto, Robert T; Forsyth, R Allyn

    2016-01-01

    We describe continuing work to develop restriction endonucleases as tools to enrich targeted genomes of interest from diverse populations. Two approaches were developed in parallel to segregate genomic DNA based on cytosine methylation. First, the methyl-sensitive endonuclease HpaII was used to bind non-CG methylated DNA. Second, a truncated fragment of McrB was used to bind CpG methylated DNA. Enrichment levels of microbial genomes can exceed 100-fold with HpaII allowing improved genomic detection and coverage of otherwise trace microbial genomes from sputum. Additionally, we observe interesting enrichment results that correlate with the methylation states not only of bacteria, but of fungi, viruses, a protist and plants. The methods presented here offer promise for testing biological samples for pathogens and global analysis of population methylomes.

  17. The New Bedford Harbor Superfund Site Long Term ...

    EPA Pesticide Factsheets

    Background. New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. Approach. A systematic, probabilistic sampling design was used to select approximately 70 sediment sampling stations. Sediment was collected at each station and chemical (e.g., PCBs, metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. There have been six sample collections to date: 1993-baseline, 1995-post hot spot removal, 1999-prior to full scale dredging, and then at 5 year intervals: 2004, 2009, and 2014. Mussel (Mytilus edulis) bioaccumulation has also been measured twice yearly. Results. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been

  18. Pearl Harbor Biological Survey

    DTIC Science & Technology

    1974-08-30

    properties, uses, and driving mechanisms affecting the harbor is given. The methods of obtaining current data, salinity profiles, and temperature... salinities were used for each calibration In order to check the salinity computation mechanism of the Instrument. Temperature calibrations were...Water Temperature Contours for Navy Thermal Discharges 3.2-23 3.2-7. General Layout of Pearl Harbor Showing Mean Monthly Salinity (3L) Variation

  19. Sediment toxicity in Savannah Harbor

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    1995-01-01

    Savannah Harbor, located near the mouth of the Savannah River, Georgia and South Carolina, is impacted by industrial and municipal effluents. Potential release of contaminants stored in harbor sediments through dredging and shipping operations requires that contaminated areas be identified for proper management of the system and protection of wildlife resources. During 1991, Hyalella azteca were exposed in 10-d static-renewal toxicity tests to pore-water and solid-phase sediment samples collected from 26 sites within Savannah Harbor. Pore-water toxicity was more pronounced than that for solidphase sediment. Toxicity and reduced leaf consumption demonstrated impaired sediment quality at specific sites within Savannah Harbor and Back River. Factors responsible for the decreased sediment quality were ammonia, alkalinity, and metal concentrations (cadmium, chromium, lead, molybdenum, and nickel). Elevated concentrations of metals and toxicities in Back River sediments indicated impacts from adjacent dredge-spoil areas.

  20. Subsidence at the Fairport Harbor Water Level Gauge

    NASA Astrophysics Data System (ADS)

    Conner, D. A.

    2014-12-01

    SUBSIDENCE AT THE FAIRPORT HARBOR WATER LEVEL GAUGE I will provide information on methods being used to monitor Lake Erie water levels and earth movement at Fairport Harbor, Ohio. Glacial Isostatic Adjustment (GIA) is responsible for vertical movement throughout the Great Lakes region. Fairport Harbor is also experiencing vertical movement due to salt mining, so the nearby water level gauge operated by the National Oceanic and Atmospheric Administration (NOAA) is affected by both GIA and mining. NOAA's National Geodetic Survey (NGS) defines and maintains the National Spatial Reference System (NSRS). The NSRS includes a network of permanently marked points; a consistent, accurate, and up-to-date national shoreline; a network of Continuously Operating Reference Stations (CORS) which supports three-dimensional positioning activities; and a set of accurate models describing dynamic, geophysical processes that affect spatial measurements. The NSRS provides the spatial reference foundation for transportation, mapping, charting and a multitude of scientific and engineering applications. Fundamental elements of geodetic infrastructure include GPS CORS (3-D), water level and tide gauges (height) and a system of vertical bench marks (height). When two or more of these elements converge they may provide an independent determination of position and vertical stability as is the case here at the Fairport Harbor water level gauge. Analysis of GPS, leveling and water level data reveal that this gauge is subsiding at about 2-3 mm/year, independent of the effects of GIA. Analysis of data from the nearby OHLA GPS CORS shows it subsiding at about 4 mm/yr, four times faster than expected due to GIA alone. A long history of salt mine activity in the area is known to geologists but it came as a surprise to other scientists.

  1. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor Breakwater... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Channel Islands Harbor, CA. 80...

  2. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor Breakwater... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Channel Islands Harbor, CA. 80...

  3. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor Breakwater... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Channel Islands Harbor, CA. 80...

  4. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor Breakwater... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Channel Islands Harbor, CA. 80...

  5. 33 CFR 80.1122 - Channel Islands Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1122 Channel Islands Harbor, CA. (a) A line drawn from Channel Islands Harbor South Jetty Light 2 to Channel Islands Harbor Breakwater... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Channel Islands Harbor, CA. 80...

  6. Early endonuclease-mediated evasion of RNA sensing ensures efficient coronavirus replication

    PubMed Central

    Kindler, Eveline; Gil-Cruz, Cristina; Spanier, Julia; Li, Yize; Wilhelm, Jochen; Rabouw, Huib H.; Züst, Roland; Marti, Sabrina; Habjan, Matthias; Cervantes-Barragan, Luisa; Elliot, Ruth; Karl, Nadja; Gaughan, Christina; Silverman, Robert H.; Keller, Markus; Ludewig, Burkhard; Bergmann, Cornelia C.; Ziebuhr, John; Kalinke, Ulrich

    2017-01-01

    Coronaviruses are of veterinary and medical importance and include highly pathogenic zoonotic viruses, such as SARS-CoV and MERS-CoV. They are known to efficiently evade early innate immune responses, manifesting in almost negligible expression of type-I interferons (IFN-I). This evasion strategy suggests an evolutionary conserved viral function that has evolved to prevent RNA-based sensing of infection in vertebrate hosts. Here we show that the coronavirus endonuclease (EndoU) activity is key to prevent early induction of double-stranded RNA (dsRNA) host cell responses. Replication of EndoU-deficient coronaviruses is greatly attenuated in vivo and severely restricted in primary cells even during the early phase of the infection. In macrophages we found immediate induction of IFN-I expression and RNase L-mediated breakdown of ribosomal RNA. Accordingly, EndoU-deficient viruses can retain replication only in cells that are deficient in IFN-I expression or sensing, and in cells lacking both RNase L and PKR. Collectively our results demonstrate that the coronavirus EndoU efficiently prevents simultaneous activation of host cell dsRNA sensors, such as Mda5, OAS and PKR. The localization of the EndoU activity at the site of viral RNA synthesis–within the replicase complex—suggests that coronaviruses have evolved a viral RNA decay pathway to evade early innate and intrinsic antiviral host cell responses. PMID:28158275

  7. Interstrand disulfide crosslinking of DNA bases supports a double nucleotide unpairing mechanism for flap endonucleases.

    PubMed

    Beddows, Amanda; Patel, Nikesh; Finger, L David; Atack, John M; Williams, David M; Grasby, Jane A

    2012-09-14

    Flap endonucleases (FENs) are proposed to select their target phosphate diester by unpairing the two terminal nucleotides of duplex. Interstrand disulfide crosslinks, introduced by oxidation of thiouracil and thioguanine bases, abolished the specificity of human FEN1 for hydrolysis one nucleotide into the 5'-duplex.

  8. The Boston Harbor Project, and large decreases in loadings of eutrophication-related materials to Boston Harbor.

    PubMed

    Taylor, David I

    2010-04-01

    Boston Harbor, a bay-estuary in the north-east USA, has recently been the site of one of the largest wastewater infrastructure projects conducted in the USA, the Boston Harbor Project (BHP). The BHP, which was conducted from 1991 to 2000, ended over a century of direct wastewater treatment facility discharges to the harbor. The BHP caused the loadings of total nitrogen (TN), total phosphorus (TP), total suspended solids (TSS) and particulate organic carbon (POC) to the harbor, to decrease by between 80% and 90%. Approximately one-third of the decreases in TSS and POC loadings occurred between 1991 and 1992; the remaining two-thirds, between 1995 and 2000. For TN and TP, the bulk of the decreases occurred between 1997 or 1998, and 2000. (c) 2009 Elsevier Ltd. All rights reserved.

  9. 33 CFR 110.38 - Edgartown Harbor, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Edgartown Harbor, Mass. 110.38 Section 110.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.38 Edgartown Harbor, Mass. An area in the inner harbor...

  10. 33 CFR 110.38 - Edgartown Harbor, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Edgartown Harbor, Mass. 110.38 Section 110.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.38 Edgartown Harbor, Mass. An area in the inner harbor...

  11. 33 CFR 110.38 - Edgartown Harbor, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Edgartown Harbor, Mass. 110.38 Section 110.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.38 Edgartown Harbor, Mass. An area in the inner harbor...

  12. 33 CFR 110.38 - Edgartown Harbor, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Edgartown Harbor, Mass. 110.38 Section 110.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.38 Edgartown Harbor, Mass. An area in the inner harbor...

  13. 33 CFR 110.38 - Edgartown Harbor, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Edgartown Harbor, Mass. 110.38 Section 110.38 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.38 Edgartown Harbor, Mass. An area in the inner harbor...

  14. Structure of the MazF-mt9 toxin, a tRNA-specific endonuclease from Mycobacterium tuberculosis.

    PubMed

    Chen, Ran; Tu, Jie; Liu, Zhihui; Meng, Fanrong; Ma, Pinyun; Ding, Zhishan; Yang, Chengwen; Chen, Lei; Deng, Xiangyu; Xie, Wei

    2017-05-06

    Tuberculosis (TB) is a severe disease caused by Mycobacterium tuberculosis (M. tb) and the well-characterized M. tb MazE/F proteins play important roles in stress adaptation. Recently, the MazF-mt9 toxin has been found to display endonuclease activities towards tRNAs but the mechanism is unknown. We hereby present the crystal structure of apo-MazF-mt9. The enzyme recognizes tRNA Lys with a central UUU motif within the anticodon loop, but is insensitive to the sequence context outside of the loop. Based on our crystallographic and biochemical studies, we identified key residues for catalysis and proposed the potential tRNA-binding site. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Big Bay Harbor Operation and Maintenance Activities, Marquette County, Michigan.

    DTIC Science & Technology

    1975-04-01

    and Custom House St. Paul, Minnesota 55101 April 1975 ENVIRON1ENTAL ASSESSMENT REPORT OPERATION AND MAINTENANCE BIG BAY HARBOR BIG BAY, MICHIGAN LAKE...these parameters is important because of the deleterious effects of the parent and breakdown products. The presence of heavy metals, taconite tailings...iron mines further south in the county. 2.522 Powell Township is governed by a town supervisor and town board, all of whom are elected. The town owns a

  16. The host-encoded RNase E endonuclease as the crRNA maturation enzyme in a CRISPR-Cas subtype III-Bv system.

    PubMed

    Behler, Juliane; Sharma, Kundan; Reimann, Viktoria; Wilde, Annegret; Urlaub, Henning; Hess, Wolfgang R

    2018-03-01

    Specialized RNA endonucleases for the maturation of clustered regularly interspaced short palindromic repeat (CRISPR)-derived RNAs (crRNAs) are critical in CRISPR-CRISPR-associated protein (Cas) defence mechanisms. The Cas6 and Cas5d enzymes are the RNA endonucleases in many class 1 CRISPR-Cas systems. In some class 2 systems, maturation and effector functions are combined within a single enzyme or maturation proceeds through the combined actions of RNase III and trans-activating CRISPR RNAs (tracrRNAs). Three separate CRISPR-Cas systems exist in the cyanobacterium Synechocystis sp. PCC 6803. Whereas Cas6-type enzymes act in two of these systems, the third, which is classified as subtype III-B variant (III-Bv), lacks cas6 homologues. Instead, the maturation of crRNAs proceeds through the activity of endoribonuclease E, leaving unusual 13- and 14-nucleotide-long 5'-handles. Overexpression of RNase E leads to overaccumulation and knock-down to the reduced accumulation of crRNAs in vivo, suggesting that RNase E is the limiting factor for CRISPR complex formation. Recognition by RNase E depends on a stem-loop in the CRISPR repeat, whereas base substitutions at the cleavage site trigger the appearance of secondary products, consistent with a two-step recognition and cleavage mechanism. These results suggest the adaptation of an otherwise very conserved housekeeping enzyme to accommodate new substrates and illuminate the impressive plasticity of CRISPR-Cas systems that enables them to function in particular genomic environments.

  17. Increased sensitivity to mitochondrial permeability transition and myonuclear translocation of endonuclease G in atrophied muscle of physically active older humans.

    PubMed

    Gouspillou, Gilles; Sgarioto, Nicolas; Kapchinsky, Sophia; Purves-Smith, Fennigje; Norris, Brandon; Pion, Charlotte H; Barbat-Artigas, Sébastien; Lemieux, Francois; Taivassalo, Tanja; Morais, José A; Aubertin-Leheudre, Mylène; Hepple, Russell T

    2014-04-01

    Mitochondrial dysfunction is implicated in skeletal muscle atrophy and dysfunction with aging, with strong support for an increased mitochondrial-mediated apoptosis in sedentary rodent models. Whether this applies to aged human muscle is unknown, nor is it clear whether these changes are caused by sedentary behavior. Thus, we examined mitochondrial function [respiration, reactive oxygen species (ROS) emission, and calcium retention capacity (CRC)] in permeabilized myofibers obtained from vastus lateralis muscle biopsies of healthy physically active young (23.7±2.7 yr; mean±SD) and older (71.2±4.9 yr) men. Although mitochondrial ROS and maximal respiratory capacity were unaffected, the acceptor control ratio was reduced by 18% with aging, suggesting mild uncoupling of oxidative phosphorylation. CRC was reduced by 50% with aging, indicating sensitization of the mitochondrial permeability transition pore (mPTP) to apoptosis. Consistent with the mPTP sensitization, older muscles showed a 3-fold greater fraction of endonuclease G (a mitochondrial proapoptotic factor)-positive myonuclei. Aged muscles also had lower mitophagic potential, based on a 43% reduction in Parkin to the voltage-dependent anion channel (VDAC) protein ratio. Collectively, these results show that mitochondrial-mediated apoptotic signaling is increased in older human muscle and suggest that accumulation of dysfunctional mitochondria with exaggerated apoptotic sensitivity is due to impaired mitophagy.

  18. 33 CFR 110.130 - Bar Harbor, Maine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bar Harbor, Maine. 110.130... ANCHORAGE REGULATIONS Anchorage Grounds § 110.130 Bar Harbor, Maine. (a) Anchorage grounds. (1) Anchorage “A” is that portion of Frenchman Bay, Bar Harbor, ME enclosed by a rhumb line connecting the following...

  19. 33 CFR 110.9 - Wells Harbor, Maine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Wells Harbor, Maine. 110.9... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.9 Wells Harbor, Maine. (a) Anchorage “A”. All of the... approximately 5,800 sq. yards, encompassing the central portion of Wells Harbor. (b) Anchorage “B”. All of the...

  20. 33 CFR 110.9 - Wells Harbor, Maine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Wells Harbor, Maine. 110.9... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.9 Wells Harbor, Maine. Link to an amendment published at..., encompassing the central portion of Wells Harbor. (b) Anchorage “B”. All of the waters enclosed by a line...

  1. 33 CFR 207.610 - St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration, and navigation of the harbor...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration, and navigation of the harbor and U.S. breakwater. 207.610 Section 207... NAVIGATION REGULATIONS § 207.610 St. Lawrence River, Cape Vincent Harbor, N.Y.; use, administration, and...

  2. Polyubiquitination of apurinic/apyrimidinic endonuclease 1 by Parkin.

    PubMed

    Scott, Timothy L; Wicker, Christina A; Suganya, Rangaswamy; Dhar, Bithika; Pittman, Thomas; Horbinski, Craig; Izumi, Tadahide

    2017-02-01

    Apurinic/apyrimidinic endonuclease 1 (APE1) is an essential protein crucial for repair of oxidized DNA damage not only in genomic DNA but also in mitochondrial DNA. Parkin, a tumor suppressor and Parkinson's disease (PD) associated gene, is an E3 ubiquitin ligase crucial for mitophagy. Although DNA damage is known to induce mitochondrial stress, Parkin's role in regulating DNA repair proteins has not been elucidated. In this study, we examined the possibility of Parkin-dependent ubiquitination of APE1. Ectopically expressed APE1 was degraded by Parkin and PINK1 via polyubiquitination in mouse embryonic fibroblast cells. PD-causing mutations in Parkin and PINK1 abrogated APE1 ubiquitination. Interaction of APE1 with Parkin was observed by co-immunoprecipitation, proximity ligation assay, and co-localization in the cytoplasm. N-terminal deletion of 41 amino acid residues in APE1 significantly reduced the Parkin-dependent APE1 degradation. These results suggested that Parkin directly ubiquitinated N-terminal Lys residues in APE1 in the cytoplasm. Modulation of Parkin and PINK1 activities under mitochondrial or oxidative stress caused moderate but statistically significant decrease of endogenous APE1 in human cell lines including SH-SY5Y, HEK293, and A549 cells. Analyses of glioblastoma tissues showed an inverse relation between the expression levels of APE1 and Parkin. These results suggest that degradation of endogenous APE1 by Parkin occur when cells are stressed to activate Parkin, and imply a role of Parkin in maintaining the quality of APE1, and loss of Parkin may contribute to elevated APE1 levels in glioblastoma. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. 33 CFR 117.272 - Boot Key Harbor.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Boot Key Harbor. 117.272 Section 117.272 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.272 Boot Key Harbor. The draw of the Boot Key Harbor drawbridge, mile 0.13, between...

  4. Defense.gov Special Report: Pearl Harbor Anniversary

    Science.gov Websites

    Department of Defense Submit Search 71th Anniversary of the Attack on Pearl Harbor - World War II News Joint Chiefs of Staff, saluted veterans at the National World War II Memorial in Washington, D.C Attack Video Return To Pearl Harbor Return To Pearl Harbor World War II Timeline The attack on Pearl

  5. Conformational Dynamics of DNA Repair by Escherichia coli Endonuclease III*

    PubMed Central

    Kuznetsov, Nikita A.; Kladova, Olga A.; Kuznetsova, Alexandra A.; Ishchenko, Alexander A.; Saparbaev, Murat K.; Zharkov, Dmitry O.; Fedorova, Olga S.

    2015-01-01

    Escherichia coli endonuclease III (Endo III or Nth) is a DNA glycosylase with a broad substrate specificity for oxidized or reduced pyrimidine bases. Endo III possesses two types of activities: N-glycosylase (hydrolysis of the N-glycosidic bond) and AP lyase (elimination of the 3′-phosphate of the AP-site). We report a pre-steady-state kinetic analysis of structural rearrangements of the DNA substrates and uncleavable ligands during their interaction with Endo III. Oligonucleotide duplexes containing 5,6-dihydrouracil, a natural abasic site, its tetrahydrofuran analog, and undamaged duplexes carried fluorescent DNA base analogs 2-aminopurine and 1,3-diaza-2-oxophenoxazine as environment-sensitive reporter groups. The results suggest that Endo III induces several fast sequential conformational changes in DNA during binding, lesion recognition, and adjustment to a catalytically competent conformation. A comparison of two fluorophores allowed us to distinguish between the events occurring in the damaged and undamaged DNA strand. Combining our data with the available structures of Endo III, we conclude that this glycosylase uses a multistep mechanism of damage recognition, which likely involves Gln41 and Leu81 as DNA lesion sensors. PMID:25869130

  6. Geoscience rediscovers Phoenicia's buried harbors

    NASA Astrophysics Data System (ADS)

    Marriner, Nick; Morhange, Christophe; Doumet-Serhal, Claude; Carbonel, Pierre

    2006-01-01

    After centuries of archaeological debate, the harbors of Phoenicia's two most important city states, Tyre and Sidon, have been rediscovered, and including new geoarcheological results reveal how, where, and when they evolved after their Bronze Age foundations. The early ports lie beneath their present urban centers, and we have indentified four harbor phases. (1) During the Bronze Age, Tyre and Sidon were characterized by semi-open marine coves that served as protoharbors. (2) Biostratigraphic and lithostratigraphic data indicate the presence of early artificial basins after the first millennium B.C. (3) The harbors reached their apogees during the Greco-Roman and Byzantine periods. (4) Silting up and coastal progradation led to burial of the medieval basins, lost until now.

  7. Modulation of the Pyrococcus abyssi NucS Endonuclease Activity by Replication Clamp at Functional and Structural Levels*

    PubMed Central

    Creze, Christophe; Ligabue, Alessio; Laurent, Sébastien; Lestini, Roxane; Laptenok, Sergey P.; Khun, Joelle; Vos, Marten H.; Czjzek, Mirjam; Myllykallio, Hannu; Flament, Didier

    2012-01-01

    Pyrococcus abyssi NucS is the founding member of a new family of structure-specific DNA endonucleases that interact with the replication clamp proliferating cell nuclear antigen (PCNA). Using a combination of small angle x-ray scattering and surface plasmon resonance analyses, we demonstrate the formation of a stable complex in solution, in which one molecule of the PabNucS homodimer binds to the outside surface of the PabPCNA homotrimer. Using fluorescent labels, PCNA is shown to increase the binding affinity of NucS toward single-strand/double-strand junctions on 5′ and 3′ flaps, as well as to modulate the cleavage specificity on the branched DNA structures. Our results indicate that the presence of a single major contact between the PabNucS and PabPCNA proteins, together with the complex-induced DNA bending, facilitate conformational flexibility required for specific cleavage at the single-strand/double-strand DNA junction. PMID:22431731

  8. Modulation of the Pyrococcus abyssi NucS endonuclease activity by replication clamp at functional and structural levels.

    PubMed

    Creze, Christophe; Ligabue, Alessio; Laurent, Sébastien; Lestini, Roxane; Laptenok, Sergey P; Khun, Joelle; Vos, Marten H; Czjzek, Mirjam; Myllykallio, Hannu; Flament, Didier

    2012-05-04

    Pyrococcus abyssi NucS is the founding member of a new family of structure-specific DNA endonucleases that interact with the replication clamp proliferating cell nuclear antigen (PCNA). Using a combination of small angle x-ray scattering and surface plasmon resonance analyses, we demonstrate the formation of a stable complex in solution, in which one molecule of the PabNucS homodimer binds to the outside surface of the PabPCNA homotrimer. Using fluorescent labels, PCNA is shown to increase the binding affinity of NucS toward single-strand/double-strand junctions on 5' and 3' flaps, as well as to modulate the cleavage specificity on the branched DNA structures. Our results indicate that the presence of a single major contact between the PabNucS and PabPCNA proteins, together with the complex-induced DNA bending, facilitate conformational flexibility required for specific cleavage at the single-strand/double-strand DNA junction.

  9. Rapid Detection of Urinary Tract Infections via Bacterial Nuclease Activity.

    PubMed

    Flenker, Katie S; Burghardt, Elliot L; Dutta, Nirmal; Burns, William J; Grover, Julia M; Kenkel, Elizabeth J; Weaver, Tyler M; Mills, James; Kim, Hyeon; Huang, Lingyan; Owczarzy, Richard; Musselman, Catherine A; Behlke, Mark A; Ford, Bradley; McNamara, James O

    2017-06-07

    Rapid and accurate bacterial detection methods are needed for clinical diagnostic, water, and food testing applications. The wide diversity of bacterial nucleases provides a rich source of enzymes that could be exploited as signal amplifying biomarkers to enable rapid, selective detection of bacterial species. With the exception of the use of micrococcal nuclease activity to detect Staphylococcus aureus, rapid methods that detect bacterial pathogens via their nuclease activities have not been developed. Here, we identify endonuclease I as a robust biomarker for E. coli and develop a rapid ultrasensitive assay that detects its activity. Comparison of nuclease activities of wild-type and nuclease-knockout E. coli clones revealed that endonuclease I is the predominant DNase in E. coli lysates. Endonuclease I is detectable by immunoblot and activity assays in uropathogenic E. coli strains. A rapid assay that detects endonuclease I activity in patient urine with an oligonucleotide probe exhibited substantially higher sensitivity for urinary tract infections than that reported for rapid urinalysis methods. The 3 hr turnaround time is much shorter than that of culture-based methods, thereby providing a means for expedited administration of appropriate antimicrobial therapy. We suggest this approach could address various unmet needs for rapid detection of E. coli. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  10. 77 FR 60109 - Takes of Marine Mammals Incidental to Specified Activities; Harbor Activities Related to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-02

    ... California sea lions (Zalophus californianus), Pacific harbor seals (Phoca vitulina), and Northern elephant... elephant seals by Level B harassment only. We have outlined the purpose of the program in a previous notice...; and Northern elephant seals by Level B harassment only. To date, we have issued nine, 1-year...

  11. 78 FR 38577 - Special Local Regulations; Red Bull Flugtag National Harbor Event, Potomac River; National Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-27

    ...-AA08 Special Local Regulations; Red Bull Flugtag National Harbor Event, Potomac River; National Harbor... waters of the Potomac River on September 21, 2013. These special local regulations are necessary to... temporarily restrict vessel traffic in a portion of the Potomac River during the event. DATES: This rule is...

  12. 76 FR 21862 - Takes of Marine Mammals Incidental to Specified Activities; Harbor Activities Related to the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... Mariner harbor operations for one year. After addressing comments from NMFS, ULA modified its application...; and 43 Northern elephant seals by Level B harassment only. To date, NMFS has issued eight, 1-year..., with the last IHA expiring on September 3, 2010 (74 FR 46742, September 11, 2009). ULA did not [[Page...

  13. A newly discovered Bordetella species carries a transcriptionally active CRISPR-Cas with a small Cas9 endonuclease.

    PubMed

    Ivanov, Yury V; Shariat, Nikki; Register, Karen B; Linz, Bodo; Rivera, Israel; Hu, Kai; Dudley, Edward G; Harvill, Eric T

    2015-10-26

    Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated genes (cas) are widely distributed among bacteria. These systems provide adaptive immunity against mobile genetic elements specified by the spacer sequences stored within the CRISPR. The CRISPR-Cas system has been identified using Basic Local Alignment Search Tool (BLAST) against other sequenced and annotated genomes and confirmed via CRISPRfinder program. Using Polymerase Chain Reactions (PCR) and Sanger DNA sequencing, we discovered CRISPRs in additional bacterial isolates of the same species of Bordetella. Transcriptional activity and processing of the CRISPR have been assessed via RT-PCR. Here we describe a novel Type II-C CRISPR and its associated genes-cas1, cas2, and cas9-in several isolates of a newly discovered Bordetella species. The CRISPR-cas locus, which is absent in all other Bordetella species, has a significantly lower GC-content than the genome-wide average, suggesting acquisition of this locus via horizontal gene transfer from a currently unknown source. The CRISPR array is transcribed and processed into mature CRISPR RNAs (crRNA), some of which have homology to prophages found in closely related species B. hinzii. Expression of the CRISPR-Cas system and processing of crRNAs with perfect homology to prophages present in closely related species, but absent in that containing this CRISPR-Cas system, suggest it provides protection against phage predation. The 3,117-bp cas9 endonuclease gene from this novel CRISPR-Cas system is 990 bp smaller than that of Streptococcus pyogenes, the 4,017-bp allele currently used for genome editing, and which may make it a useful tool in various CRISPR-Cas technologies.

  14. 78 FR 18274 - Special Local Regulations; Red Bull Flugtag National Harbor Event, Potomac River; National Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ...-AA08 Special Local Regulations; Red Bull Flugtag National Harbor Event, Potomac River; National Harbor... event,'' to be held on the waters of the Potomac River on September 21, 2013. These special local... representative. This action is intended to temporarily restrict vessel traffic in a portion of the Potomac River...

  15. Purification and characterization of an endonuclease from calf thymus acting on irradiated DNA

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

    Bacchetti, S.; Benne, R.

    1974-01-01

    An endonuclease acting on DNA exposed to ultraviolet light or gamma-rays was extensively purified from calf thymus. The enzyme has a pH optimum at pH 7.0 to 7.5, acts with equal efficiency in the presence of EDTA or divalent cations (Mg 2+ or Ca 2+), is inhibited by NaC1 and tRNA and is inactivated by incubation at 50 C. Its molecular weight, determined by Sephadex chromatography or SDS-gel electrophoresis, is + or - 30,000. The enzyme catalyzes the formation of single-strand breaks with 5'-phosphate termini in double-stranded DNA irradiated with ultraviolet or gamma-rays. It does not act on unirradiated DNAmore » or denatured DNA. The enzymatic activity on ultraviolet- and gamma-irradiated DNA is associated with the same protein. The site of action of the enzyme in ultraviolet-irradiated DNA is a photoproduct other than pyrimidine dimers, and can also be induced by irradiation of the DNA in vivo. (Author) (GRA)« less

  16. Primary processing of CRISPR RNA by the endonuclease Cas6 in Staphylococcus epidermidis.

    PubMed

    Wakefield, Noelle; Rajan, Rakhi; Sontheimer, Erik J

    2015-10-07

    In many bacteria and archaea, an adaptive immune system (CRISPR-Cas) provides immunity against foreign genetic elements. This system uses CRISPR RNAs (crRNAs) derived from the CRISPR array, along with CRISPR-associated (Cas) proteins, to target foreign nucleic acids. In most CRISPR systems, endonucleolytic processing of crRNA precursors (pre-crRNAs) is essential for the pathway. Here we study the Cas6 endonuclease responsible for crRNA processing in the Type III-A CRISPR-Cas system from Staphylococcus epidermidis RP62a, a model for Type III-A CRISPR-Cas systems, and define substrate requirements for SeCas6 activity. We find that SeCas6 is necessary and sufficient for full-length crRNA biogenesis in vitro, and that it relies on both sequence and stem-loop structure in the 3' half of the CRISPR repeat for recognition and processing. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  17. 33 CFR 162.155 - Sandusky and Huron Harbors, Ohio.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Harbors, Ohio. (a) In Sandusky Harbor, no vessel greater than 40 feet in length may exceed 10 miles per hour. (b) In Huron Harbor, no vessel greater than 40 feet in length may exceed 6 miles per hour, except in the outer harbor where no vessel greater than 40 feet in length may exceed 10 miles per hour. Note...

  18. 33 CFR 162.155 - Sandusky and Huron Harbors, Ohio.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Harbors, Ohio. (a) In Sandusky Harbor, no vessel greater than 40 feet in length may exceed 10 miles per hour. (b) In Huron Harbor, no vessel greater than 40 feet in length may exceed 6 miles per hour, except in the outer harbor where no vessel greater than 40 feet in length may exceed 10 miles per hour. Note...

  19. 33 CFR 162.155 - Sandusky and Huron Harbors, Ohio.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Harbors, Ohio. (a) In Sandusky Harbor, no vessel greater than 40 feet in length may exceed 10 miles per hour. (b) In Huron Harbor, no vessel greater than 40 feet in length may exceed 6 miles per hour, except in the outer harbor where no vessel greater than 40 feet in length may exceed 10 miles per hour. Note...

  20. 33 CFR 162.155 - Sandusky and Huron Harbors, Ohio.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Harbors, Ohio. (a) In Sandusky Harbor, no vessel greater than 40 feet in length may exceed 10 miles per hour. (b) In Huron Harbor, no vessel greater than 40 feet in length may exceed 6 miles per hour, except in the outer harbor where no vessel greater than 40 feet in length may exceed 10 miles per hour. Note...

  1. 33 CFR 162.155 - Sandusky and Huron Harbors, Ohio.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Harbors, Ohio. (a) In Sandusky Harbor, no vessel greater than 40 feet in length may exceed 10 miles per hour. (b) In Huron Harbor, no vessel greater than 40 feet in length may exceed 6 miles per hour, except in the outer harbor where no vessel greater than 40 feet in length may exceed 10 miles per hour. Note...

  2. Geographically diverse Australian isolates of Melissococcus pluton exhibit minimal genotypic diversity by restriction endonuclease analysis.

    PubMed

    Djordjevic, S P; Smith, L A; Forbes, W A; Hornitzky, M A

    1999-04-15

    Melissococcus pluton, the causative agent of European foulbrood is an economically significant disease of honey bees (Apis mellifera) across most regions of the world and is prevalent throughout most states of Australia. 49 Isolates of M. pluton recovered from diseased colonies or honey samples in New South Wales, Queensland, South Australia, Tasmania and Victoria were compared using SDS-PAGE, Western immunoblotting and restriction endonuclease analyses. DNA profiles of all 49 geographically diverse isolates showed remarkably similar AluI profiles although four isolates (one each from Queensland, South Australia, New South Wales and Victoria) displayed minor profile variations compared to AluI patterns of all other isolates. DNA from a subset of the 49 Australian and three isolates from the United Kingdom were digested separately with the restriction endonucleases CfoI, RsaI and DraI. Restriction endonuclease fragment patterns generated using these enzymes were also similar although minor variations were noted. SDS-PAGE of whole cell proteins from 13 of the 49 isolates from different states of Australia, including the four isolates which displayed minor profile variations (AluI) produced indistinguishable patterns. Major immunoreactive proteins of approximate molecular masses of 21, 24, 28, 30, 36, 40, 44, 56, 60, 71, 79 and 95 kDa were observed in immunoblots of whole cell lysates of 22 of the 49 isolates and reacted with rabbit hyperimmune antibodies raised against M. pluton whole cells. Neither SDS-PAGE or immunoblotting was capable of distinguishing differences between geographically diverse isolates of M. pluton. Collectively these data confirm that Australian isolates of M. pluton are genetically homogeneous and that this species may be clonal. Plasmid DNA was not detected in whole cell DNA profiles of any isolate resolved using agarose gel electrophoresis.

  3. 33 CFR 117.811 - Tonawanda Harbor.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tonawanda Harbor. 117.811 Section 117.811 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.811 Tonawanda Harbor. The draw of the...

  4. Engineering domain fusion chimeras from I-OnuI family LAGLIDADG homing endonucleases

    PubMed Central

    Lambert, Abigail R.; Kuhar, Ryan; Jarjour, Jordan; Kulshina, Nadia; Parmeggiani, Fabio; Danaher, Patrick; Gano, Jacob; Baker, David; Stoddard, Barry L.; Scharenberg, Andrew M.

    2012-01-01

    Although engineered LAGLIDADG homing endonucleases (LHEs) are finding increasing applications in biotechnology, their generation remains a challenging, industrial-scale process. As new single-chain LAGLIDADG nuclease scaffolds are identified, however, an alternative paradigm is emerging: identification of an LHE scaffold whose native cleavage site is a close match to a desired target sequence, followed by small-scale engineering to modestly refine recognition specificity. The application of this paradigm could be accelerated if methods were available for fusing N- and C-terminal domains from newly identified LHEs into chimeric enzymes with hybrid cleavage sites. Here we have analyzed the structural requirements for fusion of domains extracted from six single-chain I-OnuI family LHEs, spanning 40–70% amino acid identity. Our analyses demonstrate that both the LAGLIDADG helical interface residues and the linker peptide composition have important effects on the stability and activity of chimeric enzymes. Using a simple domain fusion method in which linker peptide residues predicted to contact their respective domains are retained, and in which limited variation is introduced into the LAGLIDADG helix and nearby interface residues, catalytically active enzymes were recoverable for ∼70% of domain chimeras. This method will be useful for creating large numbers of chimeric LHEs for genome engineering applications. PMID:22684507

  5. Ecological risk assessment of trace metal accumulation in sediments of Veraval Harbor, Gujarat, Arabian Sea.

    PubMed

    Sundararajan, S; Khadanga, Mukunda Kesari; Kumar, J Prince Prakash Jeba; Raghumaran, S; Vijaya, R; Jena, Basanta Kumar

    2017-01-15

    In this study, different types of indices were used to assess the ecological risk of trace metal contamination in sediments on the basis of sediment quality guidelines at Veraval Fishery Harbor. Sediment samples were collected from three sectors in pre-, post-, and monsoon seasons in 2006. Trace metal concentrations were higher in the inner sector during post-monsoon, and it showed the highest statistical significance (p<0.01) among the stations. Pollution load index was higher than unity, indicating alternation by effluent discharge from industries. Enrichment factor and geo-accumulation index showed that Cd, Pb, and Zn were enriched in the northern part of the harbor and Pb had accumulated in the harbor sediment. The ecological risk assessment index revealed that Ni, Zn, and Pb were higher than the effect range median values, indicating their potential toxicity to the aquatic environment in the Veraval Harbor. Hence, the harbor is dominated by anthropogenic activities rather than natural process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. An ultrasensitive colorimeter assay strategy for p53 mutation assisted by nicking endonuclease signal amplification.

    PubMed

    Lin, Zhenyu; Yang, Weiqiang; Zhang, Guiyun; Liu, Qida; Qiu, Bin; Cai, Zongwei; Chen, Guonan

    2011-08-28

    A novel catalytic colorimetric assay assisted by nicking endonuclease signal amplification (NESA) was developed. With the signal amplification, the detection limit of the p53 target gene can be as low as 1 pM, which is nearly 5 orders of magnitude lower than that of other previously reported colorimetric DNA detection strategies based on catalytic DNAzyme.

  7. Novel repair activities of AlkA (3-methyladenine DNA glycosylase II) and endonuclease VIII for xanthine and oxanine, guanine lesions induced by nitric oxide and nitrous acid

    PubMed Central

    Terato, Hiroaki; Masaoka, Aya; Asagoshi, Kenjiro; Honsho, Akiko; Ohyama, Yoshihiko; Suzuki, Toshinori; Yamada, Masaki; Makino, Keisuke; Yamamoto, Kazuo; Ide, Hiroshi

    2002-01-01

    Nitrosation of guanine in DNA by nitrogen oxides such as nitric oxide (NO) and nitrous acid leads to formation of xanthine (Xan) and oxanine (Oxa), potentially cytotoxic and mutagenic lesions. In the present study, we have examined the repair capacity of DNA N-glycosylases from Escherichia coli for Xan and Oxa. The nicking assay with the defined substrates containing Xan and Oxa revealed that AlkA [in combination with endonuclease (Endo) IV] and Endo VIII recognized Xan in the tested enzymes. The activity (Vmax/Km) of AlkA for Xan was 5-fold lower than that for 7-methylguanine, and that of Endo VIII was 50-fold lower than that for thymine glycol. The activity of AlkA and Endo VIII for Xan was further substantiated by the release of [3H]Xan from the substrate. The treatment of E.coli with N-methyl-N′-nitro-N-nitrosoguanidine increased the Xan-excising activity in the cell extract from alkA+ but not alkA– strains. The alkA and nei (the Endo VIII gene) double mutant, but not the single mutants, exhibited increased sensitivity to nitrous acid relative to the wild type strain. AlkA and Endo VIII also exhibited excision activity for Oxa, but the activity was much lower than that for Xan. PMID:12434002

  8. Roles of Two Shewanella oneidensis MR-1 Extracellular Endonucleases ▿ †

    PubMed Central

    Gödeke, Julia; Heun, Magnus; Bubendorfer, Sebastian; Paul, Kristina; Thormann, Kai M.

    2011-01-01

    The dissimilatory iron-reducing bacterium Shewanella oneidensis MR-1 is capable of using extracellular DNA (eDNA) as the sole source of carbon, phosphorus, and nitrogen. In addition, we recently demonstrated that S. oneidensis MR-1 requires eDNA as a structural component during all stages of biofilm formation. In this study, we characterize the roles of two Shewanella extracellular endonucleases, ExeS and ExeM. While ExeS is likely secreted into the medium, ExeM is predicted to remain associated with the cell envelope. Both exeM and exeS are highly expressed under phosphate-limited conditions. Mutants lacking exeS and/or exeM exhibit decreased eDNA degradation; however, the capability of S. oneidensis MR-1 to use DNA as the sole source of phosphorus is only affected in mutants lacking exeM. Neither of the two endonucleases alleviates toxic effects of increased eDNA concentrations. The deletion of exeM and/or exeS significantly affects biofilm formation of S. oneidensis MR-1 under static conditions, and expression of exeM and exeS drastically increases during static biofilm formation. Under hydrodynamic conditions, a deletion of exeM leads to altered biofilms that consist of densely packed structures which are covered by a thick layer of eDNA. Based on these results, we hypothesize that a major role of ExeS and, in particular, ExeM of S. oneidensis MR-1, is to degrade eDNA as a matrix component during biofilm formation to improve nutrient supply and to enable detachment. PMID:21705528

  9. 33 CFR 80.1136 - Moss Landing Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Moss Landing Harbor, CA. 80.1136... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1136 Moss Landing Harbor, CA. A line drawn from the seaward extremity of the pier located 0.3 mile south of Moss Landing Harbor Entrance to the...

  10. 33 CFR 80.1136 - Moss Landing Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Moss Landing Harbor, CA. 80.1136... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1136 Moss Landing Harbor, CA. A line drawn from the seaward extremity of the pier located 0.3 mile south of Moss Landing Harbor Entrance to the...

  11. Reducing Vulnerability of Ports and Harbors to Earthquake and Tsunami Hazards

    USGS Publications Warehouse

    Wood, Nathan J.; Good, James W.; Goodwin, Robert F.

    2002-01-01

    Recent scientific research suggests the Pacific Northwest could experience catastrophic earthquakes in the near future, both from distant and local sources, posing a significant threat to coastal communities. Damage could result from numerous earthquake-related hazards, such as severe ground shaking, soil liquefaction, landslides, land subsidence/uplift, and tsunami inundation. Because of their geographic location, ports and harbors are especially vulnerable to these hazards. Ports and harbors, however, are important components of many coastal communities, supporting numerous activities critical to the local and regional economy and possibly serving as vital post-event, response-recovery transportation links. A collaborative, multi-year initiative is underway to increase the resiliency of Pacific Northwest ports and harbors to earthquake and tsunami hazards, involving Oregon Sea Grant (OSG), Washington Sea Grant (WSG), the National Oceanic and Atmospheric Administration Coastal Services Center (CSC), and the U.S. Geological Survey Center for Science Policy (CSP). Specific products of this research, planning, and outreach initiative include a regional stakeholder issues and needs assessment, a community-based mitigation planning process, a Geographic Information System (GIS) — based vulnerability assessment methodology, an educational web-site and a regional data archive. This paper summarizes these efforts, including results of two pilot port-harbor community projects, one in Yaquina Bay, Oregon and the other in Sinclair Inlet, Washington. Finally, plans are outlined for outreach to other port and harbor communities in the Pacific Northwest and beyond, using "getting started" workshops and a web-based tutorial.

  12. 77 FR 59551 - Safety Zone, Changes to Original Rule; Boston Harbor's Rock Removal Project, Boston Inner Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-28

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2012-0767] RIN 1625-AA00 Safety Zone, Changes to Original Rule; Boston Harbor's Rock Removal Project, Boston Inner Harbor... original provisions of that temporary final rule, but adds two additional safety zones necessary for the...

  13. Fine-Scale Variability in Harbor Seal Foraging Behavior

    PubMed Central

    Wilson, Kenady; Lance, Monique; Jeffries, Steven; Acevedo-Gutiérrez, Alejandro

    2014-01-01

    Understanding the variability of foraging behavior within a population of predators is important for determining their role in the ecosystem and how they may respond to future ecosystem changes. However, such variability has seldom been studied in harbor seals on a fine spatial scale (<30 km). We used a combination of standard and Bayesian generalized linear mixed models to explore how environmental variables influenced the dive behavior of harbor seals. Time-depth recorders were deployed on harbor seals from two haul-out sites in the Salish Sea in 2007 (n = 18) and 2008 (n = 11). Three behavioral bout types were classified from six dive types within each bout; however, one of these bout types was related to haul-out activity and was excluded from analyses. Deep foraging bouts (Type I) were the predominant type used throughout the study; however, variation in the use of bout types was observed relative to haul-out site, season, sex, and light (day/night). The proportional use of Type I and Type II (shallow foraging/traveling) bouts differed dramatically between haul-out sites, seasons, sexes, and whether it was day or night; individual variability between seals also contributed to the observed differences. We hypothesize that this variation in dive behavior was related to habitat or prey specialization by seals from different haul-out sites, or individual variability between seals in the study area. The results highlight the potential influence of habitat and specialization on the foraging behavior of harbor seals, and may help explain the variability in diet that is observed between different haul-out site groups in this population. PMID:24717815

  14. Teaching about Pearl Harbor. Curriculum Enhancement Series #1.

    ERIC Educational Resources Information Center

    Shields, Anna Marshall

    These materials consist of sample lesson plans for teaching about the Japanese attack on Pearl Harbor on December 7, 1941, in both U.S. and world history classes. The lesson plans challenge students to examine how current attitudes toward the Japanese may be rooted in World War II and Pearl Harbor. Selected bibliographies on Pearl Harbor, World…

  15. The New Bedford Harbor Superfund site long-term monitoring program (1993-2009).

    PubMed

    Nelson, William G; Bergen, Barbara J

    2012-12-01

    New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. A systematic, probabilistic sampling design was used to select sediment sampling stations. This unbiased design allowed the three segments of the harbor to be compared spatially and temporally to quantify changes resulting from dredging the contaminated sediments. Sediment was collected at each station, and chemical (e.g., PCBs and metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. This paper describes the overall NBH-LTM approach and the results from the five rounds of sample collections. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been maintained since the 1993 baseline collection; however, since the onset of full-scale remediation, PCB concentrations have decreased throughout the site, and one of the benthic community indices has shown significant improvement in the lower and outer harbor areas.

  16. Evolution of I-SceI Homing Endonucleases with Increased DNA Recognition Site Specificity

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

    Joshi, Rakesh; Ho, Kwok Ki; Tenney, Kristen

    2013-09-18

    Elucidating how homing endonucleases undergo changes in recognition site specificity will facilitate efforts to engineer proteins for gene therapy applications. I-SceI is a monomeric homing endonuclease that recognizes and cleaves within an 18-bp target. It tolerates limited degeneracy in its target sequence, including substitution of a C:G{sub +4} base pair for the wild-type A:T{sub +4} base pair. Libraries encoding randomized amino acids at I-SceI residue positions that contact or are proximal to A:T{sub +4} were used in conjunction with a bacterial one-hybrid system to select I-SceI derivatives that bind to recognition sites containing either the A:T{sub +4} or the C:G{submore » +4} base pairs. As expected, isolates encoding wild-type residues at the randomized positions were selected using either target sequence. All I-SceI proteins isolated using the C:G{sub +4} recognition site included small side-chain substitutions at G100 and either contained (K86R/G100T, K86R/G100S and K86R/G100C) or lacked (G100A, G100T) a K86R substitution. Interestingly, the binding affinities of the selected variants for the wild-type A:T{sub +4} target are 4- to 11-fold lower than that of wild-type I-SceI, whereas those for the C:G{sub +4} target are similar. The increased specificity of the mutant proteins is also evident in binding experiments in vivo. These differences in binding affinities account for the observed -36-fold difference in target preference between the K86R/G100T and wild-type proteins in DNA cleavage assays. An X-ray crystal structure of the K86R/G100T mutant protein bound to a DNA duplex containing the C:G{sub +4} substitution suggests how sequence specificity of a homing enzyme can increase. This biochemical and structural analysis defines one pathway by which site specificity is augmented for a homing endonuclease.« less

  17. Functional characterization of two flap endonuclease-1 homologues in rice.

    PubMed

    Kimura, Seisuke; Furukawa, Tomoyuki; Kasai, Nobuyuki; Mori, Yoko; Kitamoto, Hiroko K; Sugawara, Fumio; Hashimoto, Junji; Sakaguchi, Kengo

    2003-09-18

    Flap endonuclease-1 (FEN-1) is an important enzyme involved in DNA replication and repair. Previously, we isolated and characterized a complementary DNA (cDNA) from rice (Oryza sativa) encoding a protein which shows homology with the eukaryotic flap endonuclease-1 (FEN-1). In this report, we found that rice (O. sativa L. cv. Nipponbare) possessed two FEN-1 homologues designated as OsFEN-1a and OsFEN-1b. The OsFEN-1a and OsFEN-1b genes were mapped to chromosome 5 and 3, respectively. Both genes contained 17 exons and 16 introns. Alignment of OsFEN-1a protein with OsFEN-1b protein showed a high degree of sequence similarity, particularly around the N and I domains. Northern hybridization and in situ hybridization analysis demonstrated preferential expression of OsFEN-1a and OsFEN-1b in proliferating tissues such as the shoot apical meristem or young leaves. The levels of OsFEN-1a and OsFEN-1b expression were significantly reduced when cell proliferation was temporarily halted by the removal of sucrose from the growth medium. When the growth-halted cells began to regrow following the addition of sucrose to the medium, both OsFEN-1a and OsFEN-1b were again expressed at high level. These results suggested that OsFEN-1a and OsFEN-1b are required for cell proliferation. Functional complementation assay suggested that OsFEN-1a cDNA had the ability to complement Saccharomyces cerevisiae rad27 null mutant. On the other hand, OsFEN-1b cDNA could not complement the rad27 mutant. The roles of OsFEN-1a and OsFEN-1b in plant DNA replication and repair are discussed.

  18. [Pearl Harbor.

    ERIC Educational Resources Information Center

    Johnson, Jennifer, Ed.

    1992-01-01

    This issue of "Loblolly Magazine" was written in observance of the 50th anniversary of the U.S. entrance into World War II. The publication features interviews conducted by East Texas high school students with Clarence Otterman, one of the few survivors of the crew of the USS Arizona, which was bombed during the attack on Pearl Harbor,…

  19. An intrinsic DFF40/CAD endonuclease deficiency impairs oligonucleosomal DNA hydrolysis during caspase-dependent cell death: a common trait in human glioblastoma cells

    PubMed Central

    Sánchez-Osuna, María; Martínez-Escardó, Laura; Granados-Colomina, Carla; Martínez-Soler, Fina; Pascual-Guiral, Sònia; Iglesias-Guimarais, Victoria; Velasco, Roser; Plans, Gerard; Vidal, Noemi; Tortosa, Avelina; Barcia, Carlos; Bruna, Jordi; Yuste, Victor J.

    2016-01-01

    Background Glioblastoma (GBM) or grade IV astrocytoma is one of the most devastating human cancers. The loss of DFF40/CAD, the key endonuclease that triggers oligonucleosomal DNA fragmentation during apoptosis, has been linked to genomic instability and cell survival after radiation. Despite the near inevitability of GBM tumor recurrence after treatment, the relationship between DFF40/CAD and GBM remains unexplored. Methods We studied the apoptotic behavior of human GBM-derived cells after apoptotic insult. We analyzed caspase activation and the protein levels and subcellular localization of DFF40/CAD apoptotic endonuclease. DFF40/CAD was also evaluated in histological sections from astrocytic tumors and nontumoral human brain. Results We showed that GBM cells undergo incomplete apoptosis without generating oligonucleosomal DNA degradation despite the correct activation of executioner caspases. The major defect of GBM cells relied on the improper accumulation of DFF40/CAD at the nucleoplasmic subcellular compartment. Supporting this finding, DFF40/CAD overexpression allowed GBM cells to display oligonucleosomal DNA degradation after apoptotic challenge. Moreover, the analysis of histological slices from astrocytic tumors showed that DFF40/CAD immunoreactivity in tumoral GFAP-positive cells was markedly reduced when compared with nontumoral samples. Conclusions Our data highlight the low expression levels of DFF40/CAD and the absence of DNA laddering as common molecular traits in GBM. These findings could be of major importance for understanding the malignant behavior of remaining tumor cells after radiochemotherapy. PMID:26755073

  20. Atypical myxomatosis--virus isolation, experimental infection of rabbits and restriction endonuclease analysis of the isolate.

    PubMed

    Psikal, I; Smíd, B; Rodák, L; Valícek, L; Bendová, J

    2003-08-01

    Atypical form of myxomatosis, which caused non-lethal and clinically mild disease in domestic rabbits 1 month after immunization with a commercially available vaccine MXT, is described. The isolated myxoma virus designated as Litovel 2 (Li-2) did not induce systemic disease following subcutaneous and intradermal applications in susceptible experimental rabbits but led to the immune response demonstrated by ELISA. No severe disease was induced in those Li-2 inoculated rabbits by challenge with the virulent strains Lausanne (Lu) or Sanar (SA), while the control animals showed nodular form of myxomatosis with lethal course of the illness. Restriction fragment length polymorphism (RFLP) of genomic DNA with KpnI and BamHI endonucleases was used for genetic characterization of the Li-2 isolate, the vaccine strain MXT and both virulent strains Lu and SA, respectively. In general, RFLP analysis has shown to be informative for inferring genetic relatedness between myxoma viruses. Based on restriction endonuclease DNA fragment size distribution, it was evident that the pathogenic strain SA is genetically related to the reference strain Lu and the isolate Li-2 is more related, but not identical, to the vaccination strain MXT.

  1. 32 CFR 765.6 - Regulations for Pearl Harbor, Hawaii.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Regulations for Pearl Harbor, Hawaii. 765.6... RULES RULES APPLICABLE TO THE PUBLIC § 765.6 Regulations for Pearl Harbor, Hawaii. The Commander, U.S. Naval Base, Pearl Harbor, Hawaii, is responsible for prescribing and enforcing such rules and...

  2. 33 CFR 110.132 - Rockland Harbor, Maine.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Rockland Harbor, Maine. 110.132... ANCHORAGE REGULATIONS Anchorage Grounds § 110.132 Rockland Harbor, Maine. (a) The anchorage grounds—(1..., power plant, oil terminal, marine terminal, munitions plant, military or naval arsenal or depot...

  3. 33 CFR 110.132 - Rockland Harbor, Maine.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Rockland Harbor, Maine. 110.132... ANCHORAGE REGULATIONS Anchorage Grounds § 110.132 Rockland Harbor, Maine. (a) The anchorage grounds—(1..., power plant, oil terminal, marine terminal, munitions plant, military or naval arsenal or depot...

  4. 33 CFR 110.132 - Rockland Harbor, Maine.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rockland Harbor, Maine. 110.132... ANCHORAGE REGULATIONS Anchorage Grounds § 110.132 Rockland Harbor, Maine. (a) The anchorage grounds—(1..., power plant, oil terminal, marine terminal, munitions plant, military or naval arsenal or depot...

  5. 33 CFR 110.132 - Rockland Harbor, Maine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rockland Harbor, Maine. 110.132... ANCHORAGE REGULATIONS Anchorage Grounds § 110.132 Rockland Harbor, Maine. (a) The anchorage grounds—(1..., power plant, oil terminal, marine terminal, munitions plant, military or naval arsenal or depot...

  6. 33 CFR 110.132 - Rockland Harbor, Maine.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rockland Harbor, Maine. 110.132... ANCHORAGE REGULATIONS Anchorage Grounds § 110.132 Rockland Harbor, Maine. (a) The anchorage grounds—(1..., power plant, oil terminal, marine terminal, munitions plant, military or naval arsenal or depot...

  7. The Use of Bacterial Repair Endonucleases in the Comet Assay.

    PubMed

    Collins, Andrew R

    2017-01-01

    The comet assay is a sensitive electrophoretic method for measuring DNA breaks at the level of single cells, used widely in genotoxicity experiments, in biomonitoring, and in fundamental research. Its sensitivity and range of application are increased by the incorporation of an extra step, after lysis of agarose-embedded cells, in which the DNA is digested with lesion-specific endonucleases (DNA repair enzymes of bacterial or phage origin). Enzymes with specificity for oxidized purines, oxidized pyrimidines, alkylated bases, UV-induced cyclobutane pyrimidine dimers, and misincorporated uracil have been employed. The additional enzyme-sensitive sites, over and above the strand breaks detected in the standard comet assay, give a quantitative estimate of the number of specific lesions present in the cells.

  8. 33 CFR 80.1116 - Redondo Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Redondo Harbor, CA. 80.1116 Section 80.1116 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1116 Redondo Harbor, CA. A line drawn from...

  9. 33 CFR 80.1116 - Redondo Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Redondo Harbor, CA. 80.1116 Section 80.1116 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1116 Redondo Harbor, CA. A line drawn from...

  10. 33 CFR 80.1108 - Oceanside Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Oceanside Harbor, CA. 80.1108 Section 80.1108 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1108 Oceanside Harbor, CA. A line drawn from...

  11. 33 CFR 80.1108 - Oceanside Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Oceanside Harbor, CA. 80.1108 Section 80.1108 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1108 Oceanside Harbor, CA. A line drawn from...

  12. 33 CFR 80.1134 - Monterey Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Monterey Harbor, CA. 80.1134 Section 80.1134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1134 Monterey Harbor, CA. A line drawn from...

  13. 33 CFR 80.1134 - Monterey Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Monterey Harbor, CA. 80.1134 Section 80.1134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1134 Monterey Harbor, CA. A line drawn from...

  14. 33 CFR 80.1134 - Monterey Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Monterey Harbor, CA. 80.1134 Section 80.1134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1134 Monterey Harbor, CA. A line drawn from...

  15. 33 CFR 80.1116 - Redondo Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Redondo Harbor, CA. 80.1116 Section 80.1116 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1116 Redondo Harbor, CA. A line drawn from...

  16. 33 CFR 80.1134 - Monterey Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Monterey Harbor, CA. 80.1134 Section 80.1134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1134 Monterey Harbor, CA. A line drawn from...

  17. 33 CFR 80.1108 - Oceanside Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Oceanside Harbor, CA. 80.1108 Section 80.1108 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1108 Oceanside Harbor, CA. A line drawn from...

  18. 33 CFR 80.1108 - Oceanside Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Oceanside Harbor, CA. 80.1108 Section 80.1108 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1108 Oceanside Harbor, CA. A line drawn from...

  19. 33 CFR 80.1116 - Redondo Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Redondo Harbor, CA. 80.1116 Section 80.1116 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1116 Redondo Harbor, CA. A line drawn from...

  20. 33 CFR 80.1116 - Redondo Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Redondo Harbor, CA. 80.1116 Section 80.1116 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1116 Redondo Harbor, CA. A line drawn from...

  1. 33 CFR 80.1134 - Monterey Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Monterey Harbor, CA. 80.1134 Section 80.1134 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1134 Monterey Harbor, CA. A line drawn from...

  2. 33 CFR 80.1108 - Oceanside Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Oceanside Harbor, CA. 80.1108 Section 80.1108 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1108 Oceanside Harbor, CA. A line drawn from...

  3. 33 CFR 110.82 - Charlevoix Harbor, Mich.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Charlevoix Harbor, Mich. 110.82 Section 110.82 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.82 Charlevoix Harbor, Mich. The waters on the north side...

  4. 33 CFR 110.50 - Stonington Harbor, Conn.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Stonington Harbor, Conn. 110.50 Section 110.50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.50 Stonington Harbor, Conn. (a) Area No. 1. Beginning at...

  5. 33 CFR 110.82 - Charlevoix Harbor, Mich.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Charlevoix Harbor, Mich. 110.82 Section 110.82 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.82 Charlevoix Harbor, Mich. The waters on the north side...

  6. 33 CFR 110.50 - Stonington Harbor, Conn.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Stonington Harbor, Conn. 110.50 Section 110.50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.50 Stonington Harbor, Conn. (a) Area No. 1. Beginning at...

  7. 33 CFR 110.82 - Charlevoix Harbor, Mich.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Charlevoix Harbor, Mich. 110.82 Section 110.82 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.82 Charlevoix Harbor, Mich. The waters on the north side...

  8. 33 CFR 110.82 - Charlevoix Harbor, Mich.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Charlevoix Harbor, Mich. 110.82 Section 110.82 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.82 Charlevoix Harbor, Mich. The waters on the north side...

  9. 33 CFR 110.50 - Stonington Harbor, Conn.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Stonington Harbor, Conn. 110.50 Section 110.50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.50 Stonington Harbor, Conn. (a) Area No. 1. Beginning at...

  10. 33 CFR 110.50 - Stonington Harbor, Conn.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Stonington Harbor, Conn. 110.50 Section 110.50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.50 Stonington Harbor, Conn. (a) Area No. 1. Beginning at...

  11. 33 CFR 110.82 - Charlevoix Harbor, Mich.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Charlevoix Harbor, Mich. 110.82 Section 110.82 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.82 Charlevoix Harbor, Mich. The waters on the north side...

  12. 33 CFR 110.50 - Stonington Harbor, Conn.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Stonington Harbor, Conn. 110.50 Section 110.50 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.50 Stonington Harbor, Conn. (a) Area No. 1. Beginning at...

  13. 33 CFR 110.142 - Nantucket Harbor, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Nantucket Harbor, Mass. 110.142 Section 110.142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.142 Nantucket Harbor, Mass. (a) The anchorage grounds. In the...

  14. 33 CFR 110.138 - Boston Harbor, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Boston Harbor, Mass. 110.138 Section 110.138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.138 Boston Harbor, Mass. (a) The anchorage grounds—(1) Bird...

  15. 33 CFR 110.142 - Nantucket Harbor, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Nantucket Harbor, Mass. 110.142 Section 110.142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.142 Nantucket Harbor, Mass. (a) The anchorage grounds. In the...

  16. 16 CFR 312.11 - Safe harbor programs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Safe harbor programs. 312.11 Section 312.11 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS CHILDREN'S ONLINE PRIVACY PROTECTION RULE § 312.11 Safe harbor programs. (a) In general. Industry groups or other persons...

  17. Erie Harbor, Pennsylvania, Channel Shoaling Analysis

    DTIC Science & Technology

    2011-07-01

    Presque Isle is located on the southern shore of Lake Erie and shelters the federal harbor at Erie , Pennsylvania . The US Army...the evaluation of the shoaling and dredging of sediment materials from Erie Harbor as part of the Presque Isle , Pennsylvania 204 feasibility study...ERDC TR-11-4 1 1 Introduction Problem statement Presque Isle is located on the southern shore of Lake Erie , Pennsylvania at the city of Erie

  18. Estuarine studies in upper Grays Harbor, Washington

    USGS Publications Warehouse

    Beverage, Joseph P.; Swecker, Milton N.

    1969-01-01

    Improved management of the water resources of Grays Harbor, Wash., requires more data on the water quality of the harbor and a better understanding of the influences of industrial and domestic wastes on the local fisheries resources. To provide a more comprehensive understanding of these influences, the U.S. Geological Survey joined other agencies in a cooperative study of Grays Harbor. This report summarizes the Survey's study of circulation patterns, description of water-quality conditions, and characterization of bottom material in the upper harbor. Salt water was found to intrude at least as far as Montesano, 28.4 nautical miles from the mouth of the harbor. Longitudinal salinity distributions were used to compute dispersion (diffusivity) coefficients ranging from 842 to 3,520 square feet per second. These values were corroborated by half-tidal-cycle dye studies. The waters of the harbor were found to be well mixed after extended periods of low fresh-water flow but stratified at high flows. Salinity data were used lo define the cumulative 'mean age' of the harbor water, which may be used to approximate a mean 'flushing time.' Velocity-time curves for the upper harbor are distorted from simple harmonic functions owing to channel geometry and frictional effects. Surface and bottom velocity data were used to estimate net tidal 'separation' distance, neglecting vertical mixing. Net separation distances between top and bottom water ranged from 1.65 nautical miles when fresh-water inflow was 610 cubic feet per second to 13.4 miles when inflow was 15,900 cubic feet per second. The cumulative mean age from integration of the fresh-water velocity equation was about twice that obtained from the salinity distribution. Excursion distances obtained with dye over half-tidal cycles exceeded those estimated from longitudinal salinity distributions and those obtained by earlier investigators who used floats. Net tidal excursions were as much as twice those obtained with floats

  19. 33 CFR 80.165 - New York Harbor.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false New York Harbor. 80.165 Section 80.165 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.165 New York Harbor. A line drawn from East...

  20. 33 CFR 110.9 - Wells Harbor, Maine.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Section 110.9 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.9 Wells Harbor, Maine. (a) Anchorage “A”. All of the... approximately 5,800 sq. yards, encompassing the central portion of Wells Harbor. (b) Anchorage “B”. All of the...

  1. 12 CFR 350.11 - Safe harbor provision.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Safe harbor provision. 350.11 Section 350.11 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY DISCLOSURE OF FINANCIAL AND OTHER INFORMATION BY FDIC-INSURED STATE NONMEMBER BANKS § 350.11 Safe harbor...

  2. 33 CFR 110.250 - St. Thomas Harbor, Charlotte Amalie, V.I.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false St. Thomas Harbor, Charlotte... SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.250 St. Thomas Harbor, Charlotte Amalie... move promptly upon notification by the Harbor Master. (4) The harbor regulations for the Port of St...

  3. Ultrasensitive signal-on DNA biosensor based on nicking endonuclease assisted electrochemistry signal amplification.

    PubMed

    Liu, Zhongyuan; Zhang, Wei; Zhu, Shuyun; Zhang, Ling; Hu, Lianzhe; Parveen, Saima; Xu, Guobao

    2011-11-15

    Combining the advantages of signal-on strategy and nicking endonuclease assisted electrochemistry signal amplification (NEAESA), a new sensitive and signal-on electrochemical DNA biosensor for the sequence specific DNA detection based on NEAESA has been developed for the first time. A Hairpin-shape probe (HP), containing the target DNA recognition sequence, is thiol-modified at 5' end and immobilized on gold electrode via Au-S bonding. Subsequently, the HP modified electrode is hybridized with target DNA to form a duplex. Then the nicking endonuclease is added and nicks the HP strand in the duplex. After nicking, 3'-ferrocene (Fc)-labeled part complementary probe (Fc-PCP) is introduced on the electrode surface by hybridizing with the thiol-modified HP fragment, which results in the generation of electrochemical signal. Hence, the DNA biosensor is constructed successfully. The present DNA biosensor shows a wide linear range of 5.0×10(-13)-5.0×10(-8)M for detecting target DNA, with a low detection limit of 0.167pM. The proposed strategy does not require any amplifying labels (enzymes, DNAzymes, nanoparticles, etc.) for biorecognition events, which avoids false-positive results to occur frequently. Moreover, the strategy has the benefits of simple preparation, convenient operation, good selectivity, and high sensitivity. With the advantages mentioned above, this simple and sensitive strategy has the potential to be integrated in portable, low cost and simplified devices for diagnostic applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Analysis of Endonuclease R·EcoRI Fragments of DNA from Lambdoid Bacteriophages and Other Viruses by Agarose-Gel Electrophoresis

    PubMed Central

    Helling, Robert B.; Goodman, Howard M.; Boyer, Herbert W.

    1974-01-01

    By means of agarose-gel electrophoresis, endonuclease R·EcoRI-generated fragments of DNA from various viruses were separated, their molecular weights were determined, and complete or partial fragment maps for lambda, φ80, and hybrid phages were constructed. Images PMID:4372397

  5. 33 CFR 117.802 - New Rochelle Harbor.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.802 New Rochelle Harbor. (a) The draw of the Glen Island Bridge, mile 0.8, at New Rochelle, New York, shall open on signal, except as... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false New Rochelle Harbor. 117.802...

  6. Multiplex, Rapid, and Sensitive Isothermal Detection of Nucleic-Acid Sequence by Endonuclease Restriction-Mediated Real-Time Multiple Cross Displacement Amplification.

    PubMed

    Wang, Yi; Wang, Yan; Zhang, Lu; Liu, Dongxin; Luo, Lijuan; Li, Hua; Cao, Xiaolong; Liu, Kai; Xu, Jianguo; Ye, Changyun

    2016-01-01

    We have devised a novel isothermal amplification technology, termed endonuclease restriction-mediated real-time multiple cross displacement amplification (ET-MCDA), which facilitated multiplex, rapid, specific and sensitive detection of nucleic-acid sequences at a constant temperature. The ET-MCDA integrated multiple cross displacement amplification strategy, restriction endonuclease cleavage and real-time fluorescence detection technique. In the ET-MCDA system, the functional cross primer E-CP1 or E-CP2 was constructed by adding a short sequence at the 5' end of CP1 or CP2, respectively, and the new E-CP1 or E-CP2 primer was labeled at the 5' end with a fluorophore and in the middle with a dark quencher. The restriction endonuclease Nb.BsrDI specifically recognized the short sequence and digested the newly synthesized double-stranded terminal sequences (5' end short sequences and their complementary sequences), which released the quenching, resulting on a gain of fluorescence signal. Thus, the ET-MCDA allowed real-time detection of single or multiple targets in only a single reaction, and the positive results were observed in as short as 12 min, detecting down to 3.125 fg of genomic DNA per tube. Moreover, the analytical specificity and the practical application of the ET-MCDA were also successfully evaluated in this study. Here, we provided the details on the novel ET-MCDA technique and expounded the basic ET-MCDA amplification mechanism.

  7. Decadal Changes In Benthic Community Measures In New York Harbor

    EPA Science Inventory

    Monitoring in New York Harbor, NY, as part of the Regional Environmental Monitoring and Assessment Program has spanned a decade, and includes habitat and water quality measures and sediment contaminant levels from four sub-basins (Upper NY Harbor, Lower NY Harbor, Newark Bay, and...

  8. Sediment resuspension characteristics in Baltimore Harbor, Maryland

    USGS Publications Warehouse

    Maa, J.P.-Y.; Sanford, L.; Halka, J.P.

    1998-01-01

    Critical bed shear stress for sediment resuspension and sediment erosion rate were measured in-situ at sites from inner to outer Baltimore Harbor using the VIMS Sea Carousel. Clay mineral contents and biological conditions were almost the same at the four study sites. The experimental results indicated that the erosion rate increased from the outer harbor toward the inner harbor with a maximum difference of about 10 times at an excess bed shear stress of 0.1 Pa. The measured critical bed shear stress strongly depended on the existence of a fluff layer. It was approximately 0.05 Pa if a fluff layer existed, and increases to about 0.1 Pa in the absence of a fluff layer.

  9. Interaction of the E. coli DNA G:T-mismatch endonuclease (vsr protein) with oligonucleotides containing its target sequence.

    PubMed

    Turner, D P; Connolly, B A

    2000-12-15

    The Escherichia coli vsr endonuclease recognises G:T base-pair mismatches in double-stranded DNA and initiates a repair pathway by hydrolysing the phosphate group 5' to the incorrectly paired T. The enzyme shows a preference for G:T mismatches within a particular sequence context, derived from the recognition site of the E. coli dcm DNA-methyltransferase (CC[A/T]GG). Thus, the preferred substrate for the vsr protein is (CT[A/T]GG), where the underlined T is opposed by a dG base. This paper provides quantitative data for the interaction of the vsr protein with a number of oligonucleotides containing G:T mismatches. Evaluation of specificity constant (k(st)/K(D); k(st)=rate constant for single turnover, K(D)=equilibrium dissociation constant) confirms vsr's preference for a G:T mismatch within a hemi-methylated dcm sequence, i.e. the best substrate is a duplex (both strands written in the 5'-3' orientation) composed of CT[A/T]GG and C(5Me)C[T/A]GG. Conversion of the mispaired T (underlined) to dU or the d(5Me)C to dC gave poorer substrates. No interaction was observed with oligonucleotides that lacked a G:T mismatch or did not possess a dcm sequence. An analysis of the fraction of active protein, by "reverse-titration" (i.e. adding increasing amounts of DNA to a fixed amount of protein followed by gel-mobility shift analysis) showed that less than 1% of the vsr endonuclease was able to bind to the substrate. This was confirmed using "competitive titrations" (where competitor oligonucleotides are used to displace a (32)P-labelled nucleic acid from the vsr protein) and burst kinetic analysis. This result is discussed in the light of previous in vitro and in vivo data which indicate that the MutL protein may be needed for full vsr activity. Copyright 2000 Academic Press.

  10. 33 CFR 110.138 - Boston Harbor, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... line running due north from Old Harbor Buoy 4 to the shore line at City Point. (5) Explosives anchorage... beacon on top of the Boston Custom House tower; and thence to the point of beginning. (2) President Roads... adjacent land; on the east by a line between Castle Rocks Fog Signal Light and Old Harbor Shoal Buoy 2; on...

  11. 33 CFR 110.138 - Boston Harbor, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... line running due north from Old Harbor Buoy 4 to the shore line at City Point. (5) Explosives anchorage... beacon on top of the Boston Custom House tower; and thence to the point of beginning. (2) President Roads... adjacent land; on the east by a line between Castle Rocks Fog Signal Light and Old Harbor Shoal Buoy 2; on...

  12. 33 CFR 110.138 - Boston Harbor, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... line running due north from Old Harbor Buoy 4 to the shore line at City Point. (5) Explosives anchorage... beacon on top of the Boston Custom House tower; and thence to the point of beginning. (2) President Roads... adjacent land; on the east by a line between Castle Rocks Fog Signal Light and Old Harbor Shoal Buoy 2; on...

  13. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (a) No vessel greater than 40 feet in length may exceed 8 miles per hour in the harbors of Michigan... Petoskey, Michigan. (b) No vessel greater than 40 feet in length may exceed 4 miles per hour in the harbors...

  14. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... (a) No vessel greater than 40 feet in length may exceed 8 miles per hour in the harbors of Michigan... Petroskey, Michigan. (b) No vessel greater than 40 feet in length may exceed 4 miles per hour in the harbors...

  15. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... (a) No vessel greater than 40 feet in length may exceed 8 miles per hour in the harbors of Michigan... Petoskey, Michigan. (b) No vessel greater than 40 feet in length may exceed 4 miles per hour in the harbors...

  16. 33 CFR 162.120 - Harbors on Lake Michigan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... (a) No vessel greater than 40 feet in length may exceed 8 miles per hour in the harbors of Michigan... Petoskey, Michigan. (b) No vessel greater than 40 feet in length may exceed 4 miles per hour in the harbors...

  17. 33 CFR 162.165 - Buffalo and Rochester Harbors, New York.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Buffalo and Rochester Harbors, New York. 162.165 Section 162.165 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... and Rochester Harbors, New York. In Buffalo and Rochester Harbors, no vessel may exceed 6 miles per...

  18. Satellite Monitoring of Boston Harbor Water Quality: Initial Investigations

    NASA Astrophysics Data System (ADS)

    Sheldon, P.; Chen, R. F.; Schaaf, C.; Pahlevan, N.; Lee, Z.

    2016-02-01

    The transformation of Boston Harbor from the "dirtiest in America" to a National Park Area is one of the most remarkable estuarine recoveries in the world. A long-term water quality dataset from 1991 to present exists in Boston Harbor due to a $3. 8 billion lawsuit requiring the harbor clean-up. This project uses discrete water sampling and underway transects with a towed vehicle coordinated with Landsat 7 and Landsat 8 to create surface maps of chlorophyll a (Chl a), dissolved organic matter (CDOM and DOC), total suspended solids (TSS), diffuse attenuation coefficient (Kd_490), and photic depth in Boston Harbor. In addition, 3 buoys have been designed, constructed, and deployed in Boston Harbor that measure Chl a and CDOM fluorescence, optical backscatter, salinity, temperature, and meteorological parameters. We are initially using summer and fall of 2015 to develop atmospheric corrections for conditions in Boston Harbor and develop algorithms for Landsat 8 data to estimate in water photic depth, TSS, Chl a, Kd_490, and CDOM. We will report on initial buoy and cruise data and show 2015 Landsat-derived distributions of water quality parameters. It is our hope that once algorithms for present Landsat imagery can be developed, historical maps of water quality can be constructed using in water data back to 1991.

  19. Single-molecule FRET unveils induced-fit mechanism for substrate selectivity in flap endonuclease 1

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

    Rashid, Fahad; Harris, Paul D.; Zaher, Manal S.

    Human flap endonuclease 1 (FEN1) and related structure-specific 5’nucleases precisely identify and incise aberrant DNA structures during replication, repair and recombination to avoid genomic instability. Yet, it is unclear how the 5’nuclease mechanisms of DNA distortion and protein ordering robustly mediate efficient and accurate substrate recognition and catalytic selectivity. Here, single-molecule sub-millisecond and millisecond analyses of FEN1 reveal a protein-DNA induced-fit mechanism that efficiently verifies substrate and suppresses off-target cleavage. FEN1 sculpts DNA with diffusion-limited kinetics to test DNA substrate. This DNA distortion mutually ‘locks’ protein and DNA conformation and enables substrate verification with extreme precision. Strikingly, FEN1 never missesmore » cleavage of its cognate substrate while blocking probable formation of catalytically competent interactions with noncognate substrates and fostering their pre-incision dissociation. These findings establish FEN1 has practically perfect precision and that separate control of induced-fit substrate recognition sets up the catalytic selectivity of the nuclease active site for genome stability.« less

  20. Single-molecule FRET unveils induced-fit mechanism for substrate selectivity in flap endonuclease 1

    DOE PAGES

    Rashid, Fahad; Harris, Paul D.; Zaher, Manal S.; ...

    2017-02-23

    Human flap endonuclease 1 (FEN1) and related structure-specific 5’nucleases precisely identify and incise aberrant DNA structures during replication, repair and recombination to avoid genomic instability. Yet, it is unclear how the 5’nuclease mechanisms of DNA distortion and protein ordering robustly mediate efficient and accurate substrate recognition and catalytic selectivity. Here, single-molecule sub-millisecond and millisecond analyses of FEN1 reveal a protein-DNA induced-fit mechanism that efficiently verifies substrate and suppresses off-target cleavage. FEN1 sculpts DNA with diffusion-limited kinetics to test DNA substrate. This DNA distortion mutually ‘locks’ protein and DNA conformation and enables substrate verification with extreme precision. Strikingly, FEN1 never missesmore » cleavage of its cognate substrate while blocking probable formation of catalytically competent interactions with noncognate substrates and fostering their pre-incision dissociation. These findings establish FEN1 has practically perfect precision and that separate control of induced-fit substrate recognition sets up the catalytic selectivity of the nuclease active site for genome stability.« less

  1. Single-molecule FRET unveils induced-fit mechanism for substrate selectivity in flap endonuclease 1

    PubMed Central

    Rashid, Fahad; Harris, Paul D; Zaher, Manal S; Sobhy, Mohamed A; Joudeh, Luay I; Yan, Chunli; Piwonski, Hubert; Tsutakawa, Susan E; Ivanov, Ivaylo; Tainer, John A; Habuchi, Satoshi; Hamdan, Samir M

    2017-01-01

    Human flap endonuclease 1 (FEN1) and related structure-specific 5’nucleases precisely identify and incise aberrant DNA structures during replication, repair and recombination to avoid genomic instability. Yet, it is unclear how the 5’nuclease mechanisms of DNA distortion and protein ordering robustly mediate efficient and accurate substrate recognition and catalytic selectivity. Here, single-molecule sub-millisecond and millisecond analyses of FEN1 reveal a protein-DNA induced-fit mechanism that efficiently verifies substrate and suppresses off-target cleavage. FEN1 sculpts DNA with diffusion-limited kinetics to test DNA substrate. This DNA distortion mutually ‘locks’ protein and DNA conformation and enables substrate verification with extreme precision. Strikingly, FEN1 never misses cleavage of its cognate substrate while blocking probable formation of catalytically competent interactions with noncognate substrates and fostering their pre-incision dissociation. These findings establish FEN1 has practically perfect precision and that separate control of induced-fit substrate recognition sets up the catalytic selectivity of the nuclease active site for genome stability. DOI: http://dx.doi.org/10.7554/eLife.21884.001 PMID:28230529

  2. Apoptosis-Resistant Cardiac Progenitor Cells Modified With Apurinic/Apyrimidinic Endonuclease/Redox Factor 1 Gene Overexpression Regulate Cardiac Repair After Myocardial Infarction.

    PubMed

    Aonuma, Tatsuya; Takehara, Naofumi; Maruyama, Keisuke; Kabara, Maki; Matsuki, Motoki; Yamauchi, Atsushi; Kawabe, Jun-Ichi; Hasebe, Naoyuki

    2016-08-01

    : Overcoming the insufficient survival of cell grafts is an essential objective in cell-based therapy. Apurinic/apyrimidinic endonuclease/redox factor 1 (APE1) promotes cell survival and may enhance the therapeutic effect of engrafted cells. The aim of this study is to determine whether APE1 overexpression in cardiac progenitor cells (CPCs) could ameliorate the efficiency of cell-based therapy. CPCs isolated from 8- to 10-week-old C57BL/6 mouse hearts were infected with retrovirus harboring APE1-DsRed (APE1-CPC) or a DsRed control (control-CPC). Oxidative stress-induced apoptosis was then assessed in APE1-CPCs, control-CPCs, and neonatal rat ventricular myocytes (NRVMs) cocultured with these CPCs. This analysis revealed that APE1 overexpression inhibited CPC apoptosis with activation of transforming growth factor β-activated kinase 1 (TAK1) and nuclear factor (NF)-κB. In the coculture model, NRVM apoptosis was inhibited to a greater extent in the presence of APE1-CPCs compared with control-CPCs. Moreover, the number of surviving DsRed-positive CPC grafts was significantly higher 7 days after the transplant of APE1-CPCs into a mouse myocardial infarction model, and the left ventricular ejection fraction showed greater improvement with attenuation of fibrosis 28 days after the transplant of APE1-CPCs compared with control-CPCs. Additionally, fewer inflammatory macrophages and a higher percentage of cardiac α-sarcomeric actinin-positive CPC-grafts were observed in mice injected with APE1-CPCs compared with control-CPCs after 7 days. In conclusion, antiapoptotic APE1-CPC graft, which increased TAK1-NF-κB pathway activation, survived effectively in the ischemic heart, restored cardiac function, and reduced cardiac inflammation and fibrosis. APE1 overexpression in CPCs may serve as a novel strategy to improve cardiac cell therapy. Improving the survival of cell grafts is essential to maximize the efficacy of cell therapy. The authors investigated the role of APE1 in

  3. 33 CFR 110.26 - Marblehead Harbor, Marblehead, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Marblehead Harbor, Marblehead, Mass. 110.26 Section 110.26 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.26 Marblehead Harbor, Marblehead...

  4. 33 CFR 110.26 - Marblehead Harbor, Marblehead, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Marblehead Harbor, Marblehead, Mass. 110.26 Section 110.26 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.26 Marblehead Harbor, Marblehead...

  5. 33 CFR 110.26 - Marblehead Harbor, Marblehead, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marblehead Harbor, Marblehead, Mass. 110.26 Section 110.26 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.26 Marblehead Harbor, Marblehead...

  6. 33 CFR 110.26 - Marblehead Harbor, Marblehead, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marblehead Harbor, Marblehead, Mass. 110.26 Section 110.26 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.26 Marblehead Harbor, Marblehead...

  7. 33 CFR 110.26 - Marblehead Harbor, Marblehead, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Marblehead Harbor, Marblehead, Mass. 110.26 Section 110.26 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.26 Marblehead Harbor, Marblehead...

  8. 33 CFR 165.125 - Regulated Navigation Area; EPA Superfund Site, New Bedford Harbor, Massachusetts.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... undue risk to environmental remediation efforts. Requests for waivers should be submitted in writing to... vessels or persons engaged in activities associated with remediation efforts in the New Bedford Harbor... advance notice of those activities by the U.S. Environmental Protection Agency (EPA). (c) Waivers. The...

  9. 33 CFR 165.125 - Regulated Navigation Area; EPA Superfund Site, New Bedford Harbor, Massachusetts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... undue risk to environmental remediation efforts. Requests for waivers should be submitted in writing to... vessels or persons engaged in activities associated with remediation efforts in the New Bedford Harbor... advance notice of those activities by the U.S. Environmental Protection Agency (EPA). (c) Waivers. The...

  10. 33 CFR 165.125 - Regulated Navigation Area; EPA Superfund Site, New Bedford Harbor, Massachusetts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... undue risk to environmental remediation efforts. Requests for waivers should be submitted in writing to... vessels or persons engaged in activities associated with remediation efforts in the New Bedford Harbor... advance notice of those activities by the U.S. Environmental Protection Agency (EPA). (c) Waivers. The...

  11. 33 CFR 165.125 - Regulated Navigation Area; EPA Superfund Site, New Bedford Harbor, Massachusetts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... undue risk to environmental remediation efforts. Requests for waivers should be submitted in writing to... vessels or persons engaged in activities associated with remediation efforts in the New Bedford Harbor... advance notice of those activities by the U.S. Environmental Protection Agency (EPA). (c) Waivers. The...

  12. Defense.gov Special Report: 72nd Anniversary of Pearl Harbor

    Science.gov Websites

    Department of Defense Submit Search 72nd Anniversary of the Attack on Pearl Harbor - World War II News Harbor survivors and World War II veterans gathered at the Pacific National Monument's Pearl Harbor course of world history." Story USS Mesa Verda Crew Conducts Remembrance Ceremony As Americans and

  13. Spectrophotometric, colorimetric and visually detection of Pseudomonas aeruginosa ETA gene based gold nanoparticles DNA probe and endonuclease enzyme

    NASA Astrophysics Data System (ADS)

    Amini, Bahram; Kamali, Mehdi; Salouti, Mojtaba; Yaghmaei, Parichehreh

    2018-06-01

    Colorimetric DNA detection is preferred over other methods for clinical molecular diagnosis because it does not require expensive equipment. In the present study, the colorimetric method based on gold nanoparticles (GNPs) and endonuclease enzyme was used for the detection of P. aeruginosa ETA gene. Firstly, the primers and probe for P. aeruginosa exotoxin A (ETA) gene were designed and checked for specificity by the PCR method. Then, GNPs were synthesized using the citrate reduction method and conjugated with the prepared probe to develop the new nano-biosensor. Next, the extracted target DNA of the bacteria was added to GNP-probe complex to check its efficacy for P. aeruginosa ETA gene diagnosis. A decrease in absorbance was seen when GNP-probe-target DNA cleaved into the small fragments of BamHI endonuclease due to the weakened electrostatic interaction between GNPs and the shortened DNA. The right shift of the absorbance peak from 530 to 562 nm occurred after adding the endonuclease. It was measured using a UV-VIS absorption spectroscopy that indicates the existence of the P. aeruginosa ETA gene. Sensitivity was determined in the presence of different concentrations of target DNA of P. aeruginosa. The results obtained from the optimized conditions showed that the absorbance value has linear correlation with concentration of target DNA (R: 0.9850) in the range of 10-50 ng mL-1 with the limit detection of 9.899 ng mL-1. Thus, the specificity of the new method for detection of P. aeruginosa was established in comparison with other bacteria. Additionally, the designed assay was quantitatively applied to detect the P. aeruginosa ETA gene from 103 to 108 CFU mL-1 in real samples with a detection limit of 320 CFU mL-1.

  14. Spectrophotometric, colorimetric and visually detection of Pseudomonas aeruginosa ETA gene based gold nanoparticles DNA probe and endonuclease enzyme.

    PubMed

    Amini, Bahram; Kamali, Mehdi; Salouti, Mojtaba; Yaghmaei, Parichehreh

    2018-06-15

    Colorimetric DNA detection is preferred over other methods for clinical molecular diagnosis because it does not require expensive equipment. In the present study, the colorimetric method based on gold nanoparticles (GNPs) and endonuclease enzyme was used for the detection of P. aeruginosa ETA gene. Firstly, the primers and probe for P. aeruginosa exotoxin A (ETA) gene were designed and checked for specificity by the PCR method. Then, GNPs were synthesized using the citrate reduction method and conjugated with the prepared probe to develop the new nano-biosensor. Next, the extracted target DNA of the bacteria was added to GNP-probe complex to check its efficacy for P. aeruginosa ETA gene diagnosis. A decrease in absorbance was seen when GNP-probe-target DNA cleaved into the small fragments of BamHI endonuclease due to the weakened electrostatic interaction between GNPs and the shortened DNA. The right shift of the absorbance peak from 530 to 562nm occurred after adding the endonuclease. It was measured using a UV-VIS absorption spectroscopy that indicates the existence of the P. aeruginosa ETA gene. Sensitivity was determined in the presence of different concentrations of target DNA of P. aeruginosa. The results obtained from the optimized conditions showed that the absorbance value has linear correlation with concentration of target DNA (R: 0.9850) in the range of 10-50ngmL -1 with the limit detection of 9.899ngmL -1 . Thus, the specificity of the new method for detection of P. aeruginosa was established in comparison with other bacteria. Additionally, the designed assay was quantitatively applied to detect the P. aeruginosa ETA gene from 10 3 to 10 8 CFUmL -1 in real samples with a detection limit of 320CFUmL -1 . Copyright © 2018 Elsevier B.V. All rights reserved.

  15. 33 CFR 80.1470 - Kawaihae Harbor, Hawaii, HI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kawaihae Harbor, Hawaii, HI. 80.1470 Section 80.1470 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1470 Kawaihae Harbor, Hawaii, HI...

  16. 33 CFR 80.1450 - Nawiliwili Harbor, Kauai, HI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Nawiliwili Harbor, Kauai, HI. 80.1450 Section 80.1450 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1450 Nawiliwili Harbor, Kauai, HI...

  17. 33 CFR 110.37 - Sesuit Harbor, Dennis, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Sesuit Harbor, Dennis, Mass. 110.37 Section 110.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.37 Sesuit Harbor, Dennis, Mass. All the waters...

  18. 33 CFR 110.37 - Sesuit Harbor, Dennis, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Sesuit Harbor, Dennis, Mass. 110.37 Section 110.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.37 Sesuit Harbor, Dennis, Mass. All the waters...

  19. 33 CFR 110.32 - Hingham Harbor, Hingham, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Hingham Harbor, Hingham, Mass. 110.32 Section 110.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.32 Hingham Harbor, Hingham, Mass. (a) Area 1...

  20. 33 CFR 110.32 - Hingham Harbor, Hingham, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hingham Harbor, Hingham, Mass. 110.32 Section 110.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.32 Hingham Harbor, Hingham, Mass. (a) Area 1...

  1. 33 CFR 110.32 - Hingham Harbor, Hingham, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Hingham Harbor, Hingham, Mass. 110.32 Section 110.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.32 Hingham Harbor, Hingham, Mass. (a) Area 1...

  2. 33 CFR 110.32 - Hingham Harbor, Hingham, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Hingham Harbor, Hingham, Mass. 110.32 Section 110.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.32 Hingham Harbor, Hingham, Mass. (a) Area 1...

  3. 33 CFR 110.37 - Sesuit Harbor, Dennis, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sesuit Harbor, Dennis, Mass. 110.37 Section 110.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.37 Sesuit Harbor, Dennis, Mass. All the waters...

  4. 33 CFR 110.37 - Sesuit Harbor, Dennis, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Sesuit Harbor, Dennis, Mass. 110.37 Section 110.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.37 Sesuit Harbor, Dennis, Mass. All the waters...

  5. 33 CFR 110.32 - Hingham Harbor, Hingham, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Hingham Harbor, Hingham, Mass. 110.32 Section 110.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.32 Hingham Harbor, Hingham, Mass. (a) Area 1...

  6. 33 CFR 110.37 - Sesuit Harbor, Dennis, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sesuit Harbor, Dennis, Mass. 110.37 Section 110.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.37 Sesuit Harbor, Dennis, Mass. All the waters...

  7. 33 CFR 110.208 - Buffalo Harbor, N.Y.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Buffalo Harbor, N.Y. 110.208 Section 110.208 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.208 Buffalo Harbor, N.Y. (a) The anchorage grounds—(1...

  8. 33 CFR 110.208 - Buffalo Harbor, N.Y.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Buffalo Harbor, N.Y. 110.208 Section 110.208 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.208 Buffalo Harbor, N.Y. (a) The anchorage grounds—(1...

  9. Mitochondrial endonuclease G mediates breakdown of paternal mitochondria upon fertilization.

    PubMed

    Zhou, Qinghua; Li, Haimin; Li, Hanzeng; Nakagawa, Akihisa; Lin, Jason L J; Lee, Eui-Seung; Harry, Brian L; Skeen-Gaar, Riley Robert; Suehiro, Yuji; William, Donna; Mitani, Shohei; Yuan, Hanna S; Kang, Byung-Ho; Xue, Ding

    2016-07-22

    Mitochondria are inherited maternally in most animals, but the mechanisms of selective paternal mitochondrial elimination (PME) are unknown. While examining fertilization in Caenorhabditis elegans, we observed that paternal mitochondria rapidly lose their inner membrane integrity. CPS-6, a mitochondrial endonuclease G, serves as a paternal mitochondrial factor that is critical for PME. We found that CPS-6 relocates from the intermembrane space of paternal mitochondria to the matrix after fertilization to degrade mitochondrial DNA. It acts with maternal autophagy and proteasome machineries to promote PME. Loss of cps-6 delays breakdown of mitochondrial inner membranes, autophagosome enclosure of paternal mitochondria, and PME. Delayed removal of paternal mitochondria causes increased embryonic lethality, demonstrating that PME is important for normal animal development. Thus, CPS-6 functions as a paternal mitochondrial degradation factor during animal development. Copyright © 2016, American Association for the Advancement of Science.

  10. RNA-cleaving properties of human apurinic/apyrimidinic endonuclease 1 (APE1)

    PubMed Central

    Kim, Wan-Cheol; King, Dustin; Lee, Chow H.

    2010-01-01

    We have recently identified apurinic/apyrimidinic endonuclease 1 (APE1) as an endoribonuclease that cleaves c-myc mRNA in vitro and regulates c-myc mRNA levels and half-life in cells. This study was undertaken to further unravel the RNA-cleaving properties of APE1. Here, we show that APE1 cleaves RNA in the absence of divalent metal ions and, at 2 mM, Zn2+, Ni2+, Cu2+, or Co2+ inhibited the endoribonuclease activity of APE1. APE1 is able to cleave CD44 mRNA, microRNAs (miR-21, miR-10b), and three RNA components of SARS-corona virus (orf1b, orf3, spike) suggesting that, when challenged, it can cleave any RNAs in vitro. APE1 does not cleave strong doublestranded regions of RNA and it has a strong preference for 3’ of pyrimidine, especially towards UA, CA, and UG sites at single-stranded or weakly paired regions. It also cleaves RNA weakly at UC, CU, AC, and AU sites in single-stranded or weakly paired regions. Finally, we found that APE1 can reduce the ability of the Dicer enzyme to process premiRNAs in vitro. Overall, this study has revealed some previously unknown biochemical properties of APE1 which has implications for its role in vivo. PMID:21968700

  11. An intrinsic DFF40/CAD endonuclease deficiency impairs oligonucleosomal DNA hydrolysis during caspase-dependent cell death: a common trait in human glioblastoma cells.

    PubMed

    Sánchez-Osuna, María; Martínez-Escardó, Laura; Granados-Colomina, Carla; Martínez-Soler, Fina; Pascual-Guiral, Sònia; Iglesias-Guimarais, Victoria; Velasco, Roser; Plans, Gerard; Vidal, Noemi; Tortosa, Avelina; Barcia, Carlos; Bruna, Jordi; Yuste, Victor J

    2016-07-01

    Glioblastoma (GBM) or grade IV astrocytoma is one of the most devastating human cancers. The loss of DFF40/CAD, the key endonuclease that triggers oligonucleosomal DNA fragmentation during apoptosis, has been linked to genomic instability and cell survival after radiation. Despite the near inevitability of GBM tumor recurrence after treatment, the relationship between DFF40/CAD and GBM remains unexplored. We studied the apoptotic behavior of human GBM-derived cells after apoptotic insult. We analyzed caspase activation and the protein levels and subcellular localization of DFF40/CAD apoptotic endonuclease. DFF40/CAD was also evaluated in histological sections from astrocytic tumors and nontumoral human brain. We showed that GBM cells undergo incomplete apoptosis without generating oligonucleosomal DNA degradation despite the correct activation of executioner caspases. The major defect of GBM cells relied on the improper accumulation of DFF40/CAD at the nucleoplasmic subcellular compartment. Supporting this finding, DFF40/CAD overexpression allowed GBM cells to display oligonucleosomal DNA degradation after apoptotic challenge. Moreover, the analysis of histological slices from astrocytic tumors showed that DFF40/CAD immunoreactivity in tumoral GFAP-positive cells was markedly reduced when compared with nontumoral samples. Our data highlight the low expression levels of DFF40/CAD and the absence of DNA laddering as common molecular traits in GBM. These findings could be of major importance for understanding the malignant behavior of remaining tumor cells after radiochemotherapy. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. A Mismatch EndoNuclease Array-Based Methodology (MENA) for Identifying Known SNPs or Novel Point Mutations.

    PubMed

    Comeron, Josep M; Reed, Jordan; Christie, Matthew; Jacobs, Julia S; Dierdorff, Jason; Eberl, Daniel F; Manak, J Robert

    2016-04-05

    Accurate and rapid identification or confirmation of single nucleotide polymorphisms (SNPs), point mutations and other human genomic variation facilitates understanding the genetic basis of disease. We have developed a new methodology (called MENA (Mismatch EndoNuclease Array)) pairing DNA mismatch endonuclease enzymology with tiling microarray hybridization in order to genotype both known point mutations (such as SNPs) as well as identify previously undiscovered point mutations and small indels. We show that our assay can rapidly genotype known SNPs in a human genomic DNA sample with 99% accuracy, in addition to identifying novel point mutations and small indels with a false discovery rate as low as 10%. Our technology provides a platform for a variety of applications, including: (1) genotyping known SNPs as well as confirming newly discovered SNPs from whole genome sequencing analyses; (2) identifying novel point mutations and indels in any genomic region from any organism for which genome sequence information is available; and (3) screening panels of genes associated with particular diseases and disorders in patient samples to identify causative mutations. As a proof of principle for using MENA to discover novel mutations, we report identification of a novel allele of the beethoven (btv) gene in Drosophila, which encodes a ciliary cytoplasmic dynein motor protein important for auditory mechanosensation.

  13. Tech Talk for Social Studies Teachers Lest We Forget: Remembering Pearl Harbor.

    ERIC Educational Resources Information Center

    Green, Tim

    2001-01-01

    Presents an annotated bibliography that provides Web sites about Pearl Harbor (Hawaii). Includes Web sites that cover Pearl Harbor history, a live view of Pearl Harbor, stories from people who remember where they were during the attack, information on the naval station at Pearl Harbor, and a virtual tour of the USS Arizona. (CMK)

  14. 33 CFR 80.1142 - San Francisco Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Francisco Harbor, CA. 80.1142 Section 80.1142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1142 San Francisco Harbor, CA. A straight line...

  15. 33 CFR 80.1136 - Moss Landing Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Moss Landing Harbor, CA. 80.1136 Section 80.1136 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1136 Moss Landing Harbor, CA. A line drawn from...

  16. 33 CFR 80.1136 - Moss Landing Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Moss Landing Harbor, CA. 80.1136 Section 80.1136 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1136 Moss Landing Harbor, CA. A line drawn from...

  17. 33 CFR 80.1152 - Crescent City Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Crescent City Harbor, CA. 80.1152 Section 80.1152 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1152 Crescent City Harbor, CA. A line drawn...

  18. 33 CFR 80.1136 - Moss Landing Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Moss Landing Harbor, CA. 80.1136 Section 80.1136 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1136 Moss Landing Harbor, CA. A line drawn from...

  19. 33 CFR 80.1140 - Pillar Point Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pillar Point Harbor, CA. 80.1140 Section 80.1140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1140 Pillar Point Harbor, CA. A line drawn from...

  20. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Santa Barbara Harbor, CA. 80.1126 Section 80.1126 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn...

  1. 33 CFR 80.1140 - Pillar Point Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pillar Point Harbor, CA. 80.1140 Section 80.1140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1140 Pillar Point Harbor, CA. A line drawn from...

  2. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Santa Barbara Harbor, CA. 80.1126 Section 80.1126 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn...

  3. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Santa Cruz Harbor, CA. 80.1138 Section 80.1138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from...

  4. 33 CFR 80.1152 - Crescent City Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Crescent City Harbor, CA. 80.1152 Section 80.1152 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1152 Crescent City Harbor, CA. A line drawn...

  5. 33 CFR 80.1110 - Dana Point Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Dana Point Harbor, CA. 80.1110 Section 80.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1110 Dana Point Harbor, CA. A line drawn from...

  6. 33 CFR 80.1110 - Dana Point Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Dana Point Harbor, CA. 80.1110 Section 80.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1110 Dana Point Harbor, CA. A line drawn from...

  7. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Santa Barbara Harbor, CA. 80.1126 Section 80.1126 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn...

  8. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Santa Cruz Harbor, CA. 80.1138 Section 80.1138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from...

  9. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Santa Cruz Harbor, CA. 80.1138 Section 80.1138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from...

  10. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Santa Barbara Harbor, CA. 80.1126 Section 80.1126 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn...

  11. 33 CFR 80.1110 - Dana Point Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Dana Point Harbor, CA. 80.1110 Section 80.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1110 Dana Point Harbor, CA. A line drawn from...

  12. 33 CFR 80.1140 - Pillar Point Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pillar Point Harbor, CA. 80.1140 Section 80.1140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1140 Pillar Point Harbor, CA. A line drawn from...

  13. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Santa Cruz Harbor, CA. 80.1138 Section 80.1138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from...

  14. 33 CFR 80.1110 - Dana Point Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Dana Point Harbor, CA. 80.1110 Section 80.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1110 Dana Point Harbor, CA. A line drawn from...

  15. 33 CFR 80.1126 - Santa Barbara Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Santa Barbara Harbor, CA. 80.1126 Section 80.1126 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1126 Santa Barbara Harbor, CA. A line drawn...

  16. 33 CFR 80.1140 - Pillar Point Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pillar Point Harbor, CA. 80.1140 Section 80.1140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1140 Pillar Point Harbor, CA. A line drawn from...

  17. 33 CFR 80.1152 - Crescent City Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Crescent City Harbor, CA. 80.1152 Section 80.1152 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1152 Crescent City Harbor, CA. A line drawn...

  18. 33 CFR 80.1142 - San Francisco Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Francisco Harbor, CA. 80.1142 Section 80.1142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1142 San Francisco Harbor, CA. A straight line...

  19. 33 CFR 80.1140 - Pillar Point Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pillar Point Harbor, CA. 80.1140 Section 80.1140 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1140 Pillar Point Harbor, CA. A line drawn from...

  20. 33 CFR 80.1142 - San Francisco Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Francisco Harbor, CA. 80.1142 Section 80.1142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1142 San Francisco Harbor, CA. A straight line...

  1. 33 CFR 80.1142 - San Francisco Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Francisco Harbor, CA. 80.1142 Section 80.1142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1142 San Francisco Harbor, CA. A straight line...

  2. 33 CFR 80.1142 - San Francisco Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Francisco Harbor, CA. 80.1142 Section 80.1142 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1142 San Francisco Harbor, CA. A straight line...

  3. 33 CFR 80.1110 - Dana Point Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Dana Point Harbor, CA. 80.1110 Section 80.1110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1110 Dana Point Harbor, CA. A line drawn from...

  4. 33 CFR 80.1138 - Santa Cruz Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Santa Cruz Harbor, CA. 80.1138 Section 80.1138 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1138 Santa Cruz Harbor, CA. A line drawn from...

  5. 33 CFR 117.722 - Great Egg Harbor Bay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Great Egg Harbor Bay. 117.722 Section 117.722 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.722 Great Egg Harbor Bay. The draw of...

  6. 33 CFR 80.1480 - Hilo Harbor, Hawaii, HI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hilo Harbor, Hawaii, HI. 80.1480 Section 80.1480 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1480 Hilo Harbor, Hawaii, HI. A line drawn...

  7. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Ponce Harbor, P.R. 110.255 Section 110.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On the...

  8. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Ponce Harbor, P.R. 110.255 Section 110.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On the...

  9. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ponce Harbor, P.R. 110.255 Section 110.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On the...

  10. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Ponce Harbor, P.R. 110.255 Section 110.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On the...

  11. 33 CFR 110.255 - Ponce Harbor, P.R.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Ponce Harbor, P.R. 110.255 Section 110.255 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.255 Ponce Harbor, P.R. (a) Small-craft anchorage. On the...

  12. 33 CFR 80.1460 - Kahului Harbor, Maui, HI.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kahului Harbor, Maui, HI. 80.1460 Section 80.1460 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Islands § 80.1460 Kahului Harbor, Maui, HI. A line drawn...

  13. 33 CFR 110.210 - San Diego Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Diego Harbor, CA. 110.210... ANCHORAGE REGULATIONS Anchorage Grounds § 110.210 San Diego Harbor, CA. (a) The anchorage grounds. (1... Commander, Naval Base, San Diego, CA. The administration of these anchorages is exercised by the Commander...

  14. 33 CFR 110.210 - San Diego Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Diego Harbor, CA. 110.210... ANCHORAGE REGULATIONS Anchorage Grounds § 110.210 San Diego Harbor, CA. (a) The anchorage grounds. (1... Commander, Naval Base, San Diego, CA. The administration of these anchorages is exercised by the Commander...

  15. 33 CFR 80.1104 - San Diego Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Diego Harbor, CA. 80.1104 Section 80.1104 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1104 San Diego Harbor, CA. A line drawn from...

  16. 33 CFR 80.1104 - San Diego Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Diego Harbor, CA. 80.1104 Section 80.1104 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1104 San Diego Harbor, CA. A line drawn from...

  17. 33 CFR 80.1104 - San Diego Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Diego Harbor, CA. 80.1104 Section 80.1104 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1104 San Diego Harbor, CA. A line drawn from...

  18. 33 CFR 110.210 - San Diego Harbor, CA.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Diego Harbor, CA. 110.210... ANCHORAGE REGULATIONS Anchorage Grounds § 110.210 San Diego Harbor, CA. (a) The anchorage grounds. (1... Commander, Naval Base, San Diego, CA. The administration of these anchorages is exercised by the Commander...

  19. 33 CFR 80.1104 - San Diego Harbor, CA.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Diego Harbor, CA. 80.1104 Section 80.1104 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1104 San Diego Harbor, CA. A line drawn from...

  20. 33 CFR 80.1104 - San Diego Harbor, CA.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Diego Harbor, CA. 80.1104 Section 80.1104 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1104 San Diego Harbor, CA. A line drawn from...

  1. 33 CFR 110.210 - San Diego Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Diego Harbor, CA. 110.210... ANCHORAGE REGULATIONS Anchorage Grounds § 110.210 San Diego Harbor, CA. (a) The anchorage grounds. (1... Commander, Naval Base, San Diego, CA. The administration of these anchorages is exercised by the Commander...

  2. 33 CFR 117.722 - Great Egg Harbor Bay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Great Egg Harbor Bay. 117.722 Section 117.722 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.722 Great Egg Harbor Bay. The draw of...

  3. Tales of some ancient harbors in the Aegean back-arc region: Earthquakes, coastal changes, historical impacts

    NASA Astrophysics Data System (ADS)

    Stiros, Stathis; Saltogianni, Vasso

    2017-04-01

    Tectonically active terrains are characterized by seismic transient ground motions (shaking) and by permanent ground motions in the vicinity of activated faults, with both effects occasionally leaving their signature on human constructions and the landscape. Especially in coastal areas marked by small tidal ranges and normal water salinity, as is the case with most parts of the Eastern Mediterranean, even small-amplitude tectonic motions can be derived from observations on coastal constructions, mainly harbors, but also on spring chambers in nearly arid environments, sewers, etc. Such observations, if coupled with well-dated observations of destructions and repairs and of changes in the occupation style of ancient sites can permit precious information conveyed from archaeology to tectonics/seismology and vice versa. A transect with harbor remains from Rhodes to the Gulf of Corinth and then till the Ionian Islands provides some excellent examples. The military harbor of Rhodes, in an area of long term uplift, a coded report of which seems to be provided by ancient poet Pindar, was subject to seismic subsidence and destruction, but with major international support, it was repaired, till renewed uplift brought it several meters above the water. In the Corinth area, the Kenchreai harbor was abruptly submerged during a major repair of a temple, as revealed by precious stained glass panels, ready to use but abandoned in shallow water beneath ruins, while radiometric dating of the uplift in the western Lechaion harbor, constrains its excavation in swampy environment not in Roman times, but to the period of flourishing of Corinth in circa 600BC and the colonization of Italy. Farther west, the sea-level mark of the harbor of Aigeira, at Mavra Litharia (Derveni/Akrata) indicates 4m uplift since the Roman period, at least partly seismic, correlating with an exposed reef and the abandonment of the repairs of the theatre of Aigeira. Seismic land uplift explains the demise of

  4. Madaket Harbor, Nantucket, Massachusetts. Water Resources Improvement.

    DTIC Science & Technology

    1977-07-01

    will continue to be, important increases in the recreational use of land and water. The harbor area is an important arena for commercial shellfishing...an important arena for commercial shell fishing. The past few years have seen a rather rapid increase in residential land use. Construction has...beamc. Tnis material will be re-deposited,, viaj troio it 1-apfro1inr ox prior location. j, MADAKET HARBOR NANTUCKET, MASSACHUSETTS FEASIBILITY

  5. 76 FR 8653 - Drawbridge Operation Regulation; Gulf Intracoastal Waterway, New Orleans Harbor, Inner Harbor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... regulation governing the operation of the SR 39 (Judge Seeber/Claiborne Avenue) vertical lift bridge across... (Judge Seeber/Claiborne Avenue) vertical lift bridge across the Inner Harbor Navigational Canal, mile 0.9...

  6. 33 CFR 80.1152 - Crescent City Harbor, CA.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Crescent City Harbor, CA. 80.1152... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1152 Crescent City Harbor, CA. A line drawn from Crescent City Entrance Light to the southeasternmost extremity of Whaler Island. [CGD 84-091, 51...

  7. 33 CFR 80.1152 - Crescent City Harbor, CA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Crescent City Harbor, CA. 80.1152... NAVIGATION RULES COLREGS DEMARCATION LINES Pacific Coast § 80.1152 Crescent City Harbor, CA. A line drawn from Crescent City Entrance Light to the southeasternmost extremity of Whaler Island. [CGD 84-091, 51...

  8. Investigation of the mechanism of meiotic DNA cleavage by VMA1-derived endonuclease uncovers a meiotic alteration in chromatin structure around the target site.

    PubMed

    Fukuda, Tomoyuki; Ohta, Kunihiro; Ohya, Yoshikazu

    2006-06-01

    VMA1-derived endonuclease (VDE), a homing endonuclease in Saccharomyces cerevisiae, is encoded by the mobile intein-coding sequence within the nuclear VMA1 gene. VDE recognizes and cleaves DNA at the 31-bp VDE recognition sequence (VRS) in the VMA1 gene lacking the intein-coding sequence during meiosis to insert a copy of the intein-coding sequence at the cleaved site. The mechanism underlying the meiosis specificity of VMA1 intein-coding sequence homing remains unclear. We studied various factors that might influence the cleavage activity in vivo and found that VDE binding to the VRS can be detected only when DNA cleavage by VDE takes place, implying that meiosis-specific DNA cleavage is regulated by the accessibility of VDE to its target site. As a possible candidate for the determinant of this accessibility, we analyzed chromatin structure around the VRS and revealed that local chromatin structure near the VRS is altered during meiosis. Although the meiotic chromatin alteration exhibits correlations with DNA binding and cleavage by VDE at the VMA1 locus, such a chromatin alteration is not necessarily observed when the VRS is embedded in ectopic gene loci. This suggests that nucleosome positioning or occupancy around the VRS by itself is not the sole mechanism for the regulation of meiosis-specific DNA cleavage by VDE and that other mechanisms are involved in the regulation.

  9. Investigation of the Mechanism of Meiotic DNA Cleavage by VMA1-Derived Endonuclease Uncovers a Meiotic Alteration in Chromatin Structure around the Target Site

    PubMed Central

    Fukuda, Tomoyuki; Ohta, Kunihiro; Ohya, Yoshikazu

    2006-01-01

    VMA1-derived endonuclease (VDE), a homing endonuclease in Saccharomyces cerevisiae, is encoded by the mobile intein-coding sequence within the nuclear VMA1 gene. VDE recognizes and cleaves DNA at the 31-bp VDE recognition sequence (VRS) in the VMA1 gene lacking the intein-coding sequence during meiosis to insert a copy of the intein-coding sequence at the cleaved site. The mechanism underlying the meiosis specificity of VMA1 intein-coding sequence homing remains unclear. We studied various factors that might influence the cleavage activity in vivo and found that VDE binding to the VRS can be detected only when DNA cleavage by VDE takes place, implying that meiosis-specific DNA cleavage is regulated by the accessibility of VDE to its target site. As a possible candidate for the determinant of this accessibility, we analyzed chromatin structure around the VRS and revealed that local chromatin structure near the VRS is altered during meiosis. Although the meiotic chromatin alteration exhibits correlations with DNA binding and cleavage by VDE at the VMA1 locus, such a chromatin alteration is not necessarily observed when the VRS is embedded in ectopic gene loci. This suggests that nucleosome positioning or occupancy around the VRS by itself is not the sole mechanism for the regulation of meiosis-specific DNA cleavage by VDE and that other mechanisms are involved in the regulation. PMID:16757746

  10. 46 CFR 7.30 - New York Harbor, NY.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false New York Harbor, NY. 7.30 Section 7.30 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Atlantic Coast § 7.30 New York Harbor, NY. A line drawn from East Rockaway Inlet Breakwater Light to Ambrose Light...

  11. Underwater noise from three types of offshore wind turbines: estimation of impact zones for harbor porpoises and harbor seals.

    PubMed

    Tougaard, Jakob; Henriksen, Oluf Damsgaard; Miller, Lee A

    2009-06-01

    Underwater noise was recorded from three different types of wind turbines in Denmark and Sweden (Middelgrunden, Vindeby, and Bockstigen-Valar) during normal operation. Wind turbine noise was only measurable above ambient noise at frequencies below 500 Hz. Total sound pressure level was in the range 109-127 dB re 1 microPa rms, measured at distances between 14 and 20 m from the foundations. The 1/3-octave noise levels were compared with audiograms of harbor seals and harbor porpoises. Maximum 1/3-octave levels were in the range 106-126 dB re 1 microPa rms. Maximum range of audibility was estimated under two extreme assumptions on transmission loss (3 and 9 dB per doubling of distance, respectively). Audibility was low for harbor porpoises extending 20-70 m from the foundation, whereas audibility for harbor seals ranged from less than 100 m to several kilometers. Behavioral reactions of porpoises to the noise appear unlikely except if they are very close to the foundations. However, behavioral reactions from seals cannot be excluded up to distances of a few hundred meters. It is unlikely that the noise reaches dangerous levels at any distance from the turbines and the noise is considered incapable of masking acoustic communication by seals and porpoises.

  12. Anthropogenic platinum and palladium in the sediments of Boston Harbor

    USGS Publications Warehouse

    Tuit, C.B.; Ravizza, G.E.; Bothner, Michael H.

    2000-01-01

    Anthropogenic activity has increased recent sediment concentrations of Pt and Pd in Boston Harbor by approximately 5 times background concentrations. Surface sediments and downcore profiles were investigated to evaluate Pt and Pd accumulation and behavior in urban coastal sediments. There is no clear correlation between temporal changes in Pt and Pd consumption and sediment concentration. However, Pt/Pb and Pd/Pb ratios suggest that Pt and Pd flux into the Harbor may not be decreasing with cessation of sludge input as rapidly as other metals. This is supported by the large discrepancy between fluxes associated with sludge and effluent release and those calculated from surface sediment concentrations. This evidence supports catalytic converters as a major source of Pd and Pt to Boston Harbor but cannot preclude other sources. Pd does not exhibit signs of post-burial remobilization below the mixed layer in the sediment cores, although near-surface variability in Pd concentrations may indicate a labile Pd component. Pt displays an inverse correlation with Mn above the oxic/suboxic transition, similar to behavior seen in pristine sediments where Pt is thought to be chemically mobile. This study does not support the use of Pd and Pt as tracers of recent contaminated sedimentation. However, the possibility of a labile Pt and Pd in these sediments highlights the need for further study of the biological uptake of these metals.

  13. Floating-Harbor syndrome associated with middle ear abnormalities.

    PubMed

    Hendrickx, Jan-Jaap; Keymolen, Kathelijn; Desprechins, Brigitte; Casselman, Jan; Gordts, Frans

    2010-01-01

    Floating-Harbor syndrome is a rare syndrome of unknown etiology, which was first described in 1973. A triad of main features characterizes Floating-Harbor syndrome: short stature, characteristic face, and an expressive speech delay. We present a patient in whom the hearing thresholds improved insufficiently after placement of grommets. High-resolution CT scan of the temporal bone showed a prominent soft-tissue thickening suspected of causing fixation of the malleus, and fusion of the malleus head with the body of the incus. To our knowledge this is the first reported abnormal middle ear anatomy in a patient with Floating-Harbor syndrome. A conservative treatment with hearing aids was preferred as an initial treatment in favor of a surgical exploration.

  14. The GAN Exonuclease or the Flap Endonuclease Fen1 and RNase HII Are Necessary for Viability of Thermococcus kodakarensis.

    PubMed

    Burkhart, Brett W; Cubonova, Lubomira; Heider, Margaret R; Kelman, Zvi; Reeve, John N; Santangelo, Thomas J

    2017-07-01

    Many aspects of and factors required for DNA replication are conserved across all three domains of life, but there are some significant differences surrounding lagging-strand synthesis. In Archaea , a 5'-to-3' exonuclease, related to both bacterial RecJ and eukaryotic Cdc45, that associates with the replisome specifically through interactions with GINS was identified and designated GAN (for G INS- a ssociated n uclease). Despite the presence of a well-characterized flap endonuclease (Fen1), it was hypothesized that GAN might participate in primer removal during Okazaki fragment maturation, and as a Cdc45 homologue, GAN might also be a structural component of an archaeal CMG (Cdc45, MCM, and GINS) replication complex. We demonstrate here that, individually, either Fen1 or GAN can be deleted, with no discernible effects on viability and growth. However, deletion of both Fen1 and GAN was not possible, consistent with both enzymes catalyzing the same step in primer removal from Okazaki fragments in vivo RNase HII has also been proposed to participate in primer processing during Okazaki fragment maturation. Strains with both Fen1 and RNase HII deleted grew well. GAN activity is therefore sufficient for viability in the absence of both RNase HII and Fen1, but it was not possible to construct a strain with both RNase HII and GAN deleted. Fen1 alone is therefore insufficient for viability in the absence of both RNase HII and GAN. The ability to delete GAN demonstrates that GAN is not required for the activation or stability of the archaeal MCM replicative helicase. IMPORTANCE The mechanisms used to remove primer sequences from Okazaki fragments during lagging-strand DNA replication differ in the biological domains. Bacteria use the exonuclease activity of DNA polymerase I, whereas eukaryotes and archaea encode a flap endonuclease (Fen1) that cleaves displaced primer sequences. RNase HII and the GINS-associated exonuclease GAN have also been hypothesized to assist in primer

  15. 33 CFR 110.95 - Newport Bay Harbor, Calif.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... (Newport Harbor Yacht Club). East of a line bearing 23° from the center of the north end of 8th Street... (Balboa Yacht Club). South of a line parallel to and 150 feet from the south pierhead line off Balboa... Newport Beach Harbor Ordinance No. 543 for pleasure boats and yachts of such sizes and alignments as...

  16. 33 CFR 110.95 - Newport Bay Harbor, Calif.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... (Newport Harbor Yacht Club). East of a line bearing 23° from the center of the north end of 8th Street... (Balboa Yacht Club). South of a line parallel to and 150 feet from the south pierhead line off Balboa... Newport Beach Harbor Ordinance No. 543 for pleasure boats and yachts of such sizes and alignments as...

  17. 33 CFR 100.113 - Provincetown Harbor Swim for Life, Provincetown, MA.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Provincetown Harbor Swim for Life... SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.113 Provincetown Harbor Swim for Life, Provincetown, MA. (a) Regulated Area. All waters of Provincetown Harbor within 200 feet of...

  18. Mucoepidermoid carcinoma does not harbor transcriptionally active high risk human papillomavirus even in the absence of the MAML2 translocation.

    PubMed

    Bishop, Justin A; Yonescu, Raluca; Batista, Denise; Yemelyanova, Anna; Ha, Patrick K; Westra, William H

    2014-01-01

    High risk human papillomavirus (HPV) is firmly established as an important cause of oropharyngeal carcinoma. Recent studies have also implicated HPV as a cause of mucoepidermoid carcinoma (MEC)-a tumor of salivary gland origin that frequently harbors MAML2 translocations. The purpose of this study was to determine the prevalence of transcriptionally active HPV in a large group of MECs and to determine whether HPV infection and the MAML2 translocation are mutually exclusive events. Break-apart fluorescence in situ hybridization for MAML2 was performed on a tissue microarray containing 92 MECs. HPV testing was performed using RNA in situ hybridization targeting high risk HPV mRNA E6/E7 transcripts. Of the 71 MECs that could be evaluated by FISH, 57 (80 %) harbored the MAML2 rearrangement. HPV was not detected in any of the 57 MECs that contained a MAML2 rearrangement, in any of the 14 MECs that did not contain the rearrangement, or in any of the 21 MECs where MAML2 status was unknown. High risk HPV does not appear to play any significant role in the development of MEC. It neither complements nor replaces MAML2 translocation in the tumorigenesis of MEC.

  19. Penialidins A-C with strong antibacterial activities from Penicillium sp., an endophytic fungus harboring leaves of Garcinia nobilis.

    PubMed

    Jouda, Jean-Bosco; Kusari, Souvik; Lamshöft, Marc; Mouafo Talontsi, Ferdinand; Douala Meli, Clovis; Wandji, Jean; Spiteller, Michael

    2014-10-01

    Three new polyketides named penialidins A-C (1-3), along with one known compound, citromycetin (4), were isolated from an endophytic fungus, Penicillium sp., harbored in the leaves of the Cameroonian medicinal plant Garcinia nobilis. Their structures were elucidated by means of spectroscopic and spectrometric methods (NMR and HRMS(n)). The antibacterial efficacies of the new compounds (1-3) were tested against the clinically-important risk group 2 (RG2) bacterial strains of Staphylococcus aureus and Escherichia coli. The ecologically imposing strains of E. coli (RG1), Bacillus subtilis and Acinetobacter sp. BD4 were also included in the assay. Compound 3 exhibited pronounced activity against the clinically-relevant S. aureus as well as against B. subtilis comparable to that of the reference standard (streptomycin). Compound 2 was also highly-active against S. aureus. By comparing the structures of the three new compounds (1-3), it was revealed that altering the substitutions at C-10 and C-2 can significantly increase the antibacterial activity of 1. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Composition and source of butyltins in sediments of Kaohsiung Harbor, Taiwan

    NASA Astrophysics Data System (ADS)

    Dong, Cheng-Di; Chen, Chih-Feng; Chen, Chiu-Wen

    2015-04-01

    Fifty-eight sediment samples were collected from the Kaohsiung Harbor (Taiwan) for analyses of monobutyltin (MBT), dibutyltin (DBT) and tributyltin (TBT), using gas chromatography/flame photometric detector (GC/FPD). The concentration of total butyltins (ΣBTs), sum of MBT, DBT, and TBT, varied from 3.9 to 158.5 ng Sn/g dw in sediment samples with TBT being the major component of the sediment samples, except for the vicinity of the Love River mouth where MBT was the most abundant BT compound (a proportion of over 57%). Based on the BTs concentration, distribution, composition and correlations, the sources of BTs found in harbor sediments are shipping activities, and TBT is the main pollutant; the estuary (i.e. Love River) has been the anthropogenic source of MBT from upstream inputs. Influences of TBT on aquatic organisms are evaluated using the toxicity guidelines proposed by the US EPA (US Environmental Protection Agency) and the ACCI (assessment class criterion for imposex) proposed by OSPAR (Oslo and Paris Commission). The evaluation shows that the TBT contained in the sediment at Kaohsiung Harbor is likely to have a negative influence at ACCI class C because gastropods present imposex and TBT levels are above ecotoxicological assessment criteria (EAC) limits.

  1. 77 FR 45239 - Amendment of Class E Airspace; Bar Harbor, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-31

    ...-1366; Airspace Docket No. 11-ANE-13] Amendment of Class E Airspace; Bar Harbor, ME AGENCY: Federal... area at Bar Harbor, ME, as the Surry Non-Directional Radio Beacon (NDB) has been decommissioned and new... airspace at Bar Harbor, ME (77 FR 27666) Docket No. FAA-2011-1366. Interested parties were invited to...

  2. Active site electrostatics protect genome integrity by blocking abortive hydrolysis during DNA recombination

    PubMed Central

    Ma, Chien-Hui; Rowley, Paul A; Macieszak, Anna; Guga, Piotr; Jayaram, Makkuni

    2009-01-01

    Water, acting as a rogue nucleophile, can disrupt transesterification steps of important phosphoryl transfer reactions in DNA and RNA. We have unveiled this risk, and identified safeguards instituted against it, during strand cleavage and joining by the tyrosine site-specific recombinase Flp. Strand joining is threatened by a latent Flp endonuclease activity (type I) towards the 3′-phosphotyrosyl intermediate resulting from strand cleavage. This risk is not alleviated by phosphate electrostatics; neutralizing the negative charge on the scissile phosphate through methylphosphonate (MeP) substitution does not stimulate type I endonuclease. Rather, protection derives from the architecture of the recombination synapse and conformational dynamics within it. Strand cleavage is protected against water by active site electrostatics. Replacement of the catalytic Arg-308 of Flp by alanine, along with MeP substitution, elicits a second Flp endonuclease activity (type II) that directly targets the scissile phosphodiester bond in DNA. MeP substitution, combined with appropriate active site mutations, will be useful in revealing anti-hydrolytic mechanisms engendered by systems that mediate DNA relaxation, DNA transposition, site-specific recombination, telomere resolution, RNA splicing and retrohoming of mobile introns. PMID:19440204

  3. New World Bats Harbor Diverse Influenza A Viruses

    PubMed Central

    Tong, Suxiang; Zhu, Xueyong; Li, Yan; Shi, Mang; Zhang, Jing; Bourgeois, Melissa; Yang, Hua; Chen, Xianfeng; Recuenco, Sergio; Gomez, Jorge; Chen, Li-Mei; Johnson, Adam; Tao, Ying; Dreyfus, Cyrille; Yu, Wenli; McBride, Ryan; Carney, Paul J.; Gilbert, Amy T.; Chang, Jessie; Guo, Zhu; Davis, Charles T.; Paulson, James C.; Stevens, James; Rupprecht, Charles E.; Holmes, Edward C.; Wilson, Ian A.; Donis, Ruben O.

    2013-01-01

    Aquatic birds harbor diverse influenza A viruses and are a major viral reservoir in nature. The recent discovery of influenza viruses of a new H17N10 subtype in Central American fruit bats suggests that other New World species may similarly carry divergent influenza viruses. Using consensus degenerate RT-PCR, we identified a novel influenza A virus, designated as H18N11, in a flat-faced fruit bat (Artibeus planirostris) from Peru. Serologic studies with the recombinant H18 protein indicated that several Peruvian bat species were infected by this virus. Phylogenetic analyses demonstrate that, in some gene segments, New World bats harbor more influenza virus genetic diversity than all other mammalian and avian species combined, indicative of a long-standing host-virus association. Structural and functional analyses of the hemagglutinin and neuraminidase indicate that sialic acid is not a ligand for virus attachment nor a substrate for release, suggesting a unique mode of influenza A virus attachment and activation of membrane fusion for entry into host cells. Taken together, these findings indicate that bats constitute a potentially important and likely ancient reservoir for a diverse pool of influenza viruses. PMID:24130481

  4. Geochemical investigation of a sediment core from the Trajan basin at Portus, the harbor of ancient Rome

    NASA Astrophysics Data System (ADS)

    Delile, H.; Mazzini, I.; Blichert-Toft, J.; Goiran, J. P.; Arnaud-Godet, F.; Salomon, F.; Albarède, F.

    2014-03-01

    From the 1st century AD and for the duration of the Roman Empire, the Portus complex was the main harbor of Rome. Its location on the Tiber delta next to the Tyrrhenian Sea produced rapid environmental changes that, together with historical vicissitudes, largely determined the fate of the harbor. We have assembled data on the mineralogy, sedimentology, geochemistry, and ostracod populations of a sediment core drilled in the access channel of the hexagonal basin of Trajan, with the expectation that such a combined data set will shed new light on how the connections of the inland Trajan basin with the Tiber river, the earlier Claudius harbor on the nearby shoreline, and the sea evolved through the centuries. The data define four distinct periods which geochemistry characterizes by different conditions of salinity and oxygenation. These in turn can be related to historical periods and events by means of 14C data. The early Imperial Period was dominated by input of well-oxygenated freshwater from the Tiber. During the Late Empire, harbor water became relatively more influenced by seawater and increasingly oxygen deficient, which attests to a decommissioning of the Canale Trasverso connecting the harbor to the Tiber. The strong anthropogenic signal, which is visible very clearly in geochemical parameters, attests to the human occupation of the harbor area up to the Early Middle Ages, when human activity was brought to an abrupt end. The simultaneous use in this study of multiple complementary tracers has allowed for the sedimentary sources of the different classes of particles in the harbor basin to be identified and assigned to either the freshwater supply from the Canale Trasverso or the seawater of the Claudius harbor.

  5. Planning through Partnerships : Alternative Transportation at Boston Harbor Islands National Park Area

    DOT National Transportation Integrated Search

    2004-07-31

    This case study tells the story of a successful and collaborative transportation planning process at Boston Harbor Islands National Park Area (Boston Harbor Islands). By using an innovative approach to planning, Boston Harbor Islands has been able to...

  6. Restriction Endonucleases from Invasive Neisseria gonorrhoeae Cause Double-Strand Breaks and Distort Mitosis in Epithelial Cells during Infection

    PubMed Central

    Weyler, Linda; Engelbrecht, Mattias; Mata Forsberg, Manuel; Brehwens, Karl; Vare, Daniel; Vielfort, Katarina; Wojcik, Andrzej; Aro, Helena

    2014-01-01

    The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies. PMID:25460012

  7. Restriction endonucleases from invasive Neisseria gonorrhoeae cause double-strand breaks and distort mitosis in epithelial cells during infection.

    PubMed

    Weyler, Linda; Engelbrecht, Mattias; Mata Forsberg, Manuel; Brehwens, Karl; Vare, Daniel; Vielfort, Katarina; Wojcik, Andrzej; Aro, Helena

    2014-01-01

    The host epithelium is both a barrier against, and the target for microbial infections. Maintaining regulated cell growth ensures an intact protective layer towards microbial-induced cellular damage. Neisseria gonorrhoeae infections disrupt host cell cycle regulation machinery and the infection causes DNA double strand breaks that delay progression through the G2/M phase. We show that intracellular gonococci upregulate and release restriction endonucleases that enter the nucleus and damage human chromosomal DNA. Bacterial lysates containing restriction endonucleases were able to fragment genomic DNA as detected by PFGE. Lysates were also microinjected into the cytoplasm of cells in interphase and after 20 h, DNA double strand breaks were identified by 53BP1 staining. In addition, by using live-cell microscopy and NHS-ester stained live gonococci we visualized the subcellular location of the bacteria upon mitosis. Infected cells show dysregulation of the spindle assembly checkpoint proteins MAD1 and MAD2, impaired and prolonged M-phase, nuclear swelling, micronuclei formation and chromosomal instability. These data highlight basic molecular functions of how gonococcal infections affect host cell cycle regulation, cause DNA double strand breaks and predispose cellular malignancies.

  8. Lignification induced by pseudomonads harboring avirulent genes on Arabidopsis.

    PubMed

    Lee, S; Sharm, Y; Lee, T K; Chang, M; Davis, K R

    2001-08-31

    The responses of Arabidopsis thaliana ecotypes to the bacterial pathogen Pseudomonas syringae pv. maculicola 4326 (Psm4326) harboring cloned avirulence genes avrB and avrRpt2 from P. syringae pv. glycinea were examined. Psm4326 containing avirulent genes, avrB and avrRpt2 induced lignification and peroxidase activities in the bacteria infiltrated leaves of Col-O only and not in Mt-O, Bla-2 and Po-1. However, Arabidopsis ecotypes infiltrated with Psm4326 harboring with and without avirulent genes all showed differential induction of mRNA for peroxidase gene and lignin accumulation up to 24 h after infiltration. Only avrB gene in Col-O showed strong corelationship between peroxidase mRNA expression as well as lignification gradually up to 36 h after infiltration. These results extend previous observations that avirulence genes from pathogens of one host plant can be recognized by non-host plants and provide the genetic framework for analysis of the plant-specific response to the bacterial avirulent gene products in A. thaliana.

  9. Geotechnical and Geoacoustic Investigation of Seafloor Sediments on Boston Harbor Approaches

    DTIC Science & Technology

    2017-01-25

    Geoacoustic Investigation of Seafloor Sediments on Boston Harbor Approaches Andrei Abelev Marine Physics Branch Marine Geosciences Division Peter...LIMITATION OF ABSTRACT Geotechnical and Geoacoustic Investigation of Seafloor Sediments on Boston Harbor Approaches Andrei Abelev, Peter Herdic...sampling and analysis series for classification and characterization of the surficial seafloor sediment in the Boston Harbor approaches . 25-01-2017

  10. Prevalence of antibodies against Ehrlichia spp. and Orientia tsutsugamushi in small mammals around harbors in Taiwan.

    PubMed

    Tsai, Kun-Hsien; Chang, Shu-Feng; Yen, Tsai-Ying; Shih, Wei-Liang; Chen, Wan-Jen; Wang, Hsi-Chieh; Yu, Xue-Jie; Wen, Tzai-Hung; Wu, Wen-Jer; Shu, Pei-Yun

    2016-01-27

    Tick-borne ehrlichiosis and mite-borne scrub typhus represent important emerging zoonotic rickettsial diseases. Although scrub typhus has been recognized by the Taiwanese public health system, information on ehrlichial infections is scarce in Taiwan. In this study, the risk of spread of ectoparasites on rodents through aerial and marine transportation was assessed in international and domestic harbors. Here, we report the first systematic surveillance of seroprevalence against Ehrlichia spp. in small mammals on the main island of Taiwan. In total, 1648 small mammals were trapped from 8 international ports, 18 domestic fishing harbors, and 7 local public health centers around Taiwan from November 2004 to December 2008. Sera were analyzed using indirect immunofluorescence assays to detect IgG antibodies against Ehrlichia chaffeensis and Orientia tsutsugamushi. A serum titer of ≧1:80 was considered positive. Antibodies against Ehrlichia spp. and O. tsutsugamushi were detected in 3.28% and 4.92% of small mammals active around harbors, respectively. The seropositive rate against Ehrlichia was higher in northern Taiwan from 2005 to 2008. However, O. tsutsugamushi infections increased in southern Taiwan during this period. The serological evidence of ehrlichial and O. tsutsugamushi infections in all international ports were included in the study. No significant differences were found among the seropositive rates of Ehrlichia spp. and O. tsutsugamushi in small mammals trapped between international and local harbors. The overall prevalence of Ehrlichia spp. and O. tsutsugamushi infections in small mammals active around harbors was 3.28% and 4.92%, respectively. The results provided serological evidence supporting the potential risks of transporting pathogens through air and maritime traffic. This study highlights serious issues of the emergence and spread of rickettsial diseases in Taiwan. The incidence of human ehrlichiosis requires further investigation.

  11. Ground-water status report, Pearl Harbor area, Hawaii, 1978

    USGS Publications Warehouse

    Soroos, Ronald L.; Ewart, Charles J.

    1979-01-01

    Increasing demand for freshwater in Hawaii has placed heavy stress on many of the State 's basal aquifer systems. The most heavily stressed of these systems is the Pearl Harbor on Oahu. The Pearl Harbor basal aquifer supplies as much as 277 million gallons per day. Since early in this century, spring discharge has been declining while pumpage has been increasing. Total ground-water discharge has remained steady despite short-term fluctuations. Some wells show general increases in chloride concentration while others remain steady. Chloride concentrations throughout the area show no apparent increase since 1970. Basal water head maps of the Pearl Harbor area clearly reflect the natural discharge points, which are the springs located along the shore near the center of Pearl Harbor. Basal-water hydrographs show a general decline of about 0.09 foot per year. This implies depletion of storage at a rate of about 25 million gallons per day. (USGS).

  12. Pollutant Concentrations and Toxic Effects on the Red Alga Ceramium tenuicorne of Sediments from Natural Harbors and Small Boat Harbors on the West Coast of Sweden.

    PubMed

    Eklund, Britta; Hansson, Tomas; Bengtsson, Henrik; Eriksson Wiklund, Ann-Kristin

    2016-04-01

    This investigation set out to analyze the toxicity of surface sediments in a number of natural harbors and small boat harbors on the west coast of Sweden. This was done with the growth inhibition method with Ceramium tenuicorne. Also, concentrations of copper (Cu), lead (Pb), zinc (Zn), irgarol, organotin compounds, and polycyclic aromatic hydrocarbons (PAHs) in the sediments were analyzed. The small boat harbors were heavily polluted by Cu, Zn, butyltins, and PAHs, and to a lesser extent by Pb. The Cu, Pb, Zn, and butyltins probably originated from their past and/or present use in antifouling paints, whereas the PAHs probably had multiple sources, including boat motor exhausts. The measured toxicity of the sediment was generally related to their Cu, Zn, and butyltin content, although other toxic substances than those analyzed here probably contributed to the toxicity in some of the harbors. The natural harbor sediments contained less pollutants and were less toxic than the small boat harbor sediments. Nevertheless, our data indicate that the boating pressure today may be high enough to produce toxic effects even in natural harbors in pristine areas. The strongest relationship between toxicity and the major pollutants was obtained when the sediment toxicity was expressed as gram wet weight per liter compared with gram dry weight per liter and gram total organic carbon per liter. Hence, for pollutants that can be elutriated with natural sea water, sediment toxicity expressed as gram wet weight per liter appears preferable.

  13. Endonuclease G mediates α-synuclein cytotoxicity during Parkinson's disease.

    PubMed

    Büttner, Sabrina; Habernig, Lukas; Broeskamp, Filomena; Ruli, Doris; Vögtle, F Nora; Vlachos, Manolis; Macchi, Francesca; Küttner, Victoria; Carmona-Gutierrez, Didac; Eisenberg, Tobias; Ring, Julia; Markaki, Maria; Taskin, Asli Aras; Benke, Stefan; Ruckenstuhl, Christoph; Braun, Ralf; Van den Haute, Chris; Bammens, Tine; van der Perren, Anke; Fröhlich, Kai-Uwe; Winderickx, Joris; Kroemer, Guido; Baekelandt, Veerle; Tavernarakis, Nektarios; Kovacs, Gabor G; Dengjel, Jörn; Meisinger, Chris; Sigrist, Stephan J; Madeo, Frank

    2013-11-27

    Malfunctioning of the protein α-synuclein is critically involved in the demise of dopaminergic neurons relevant to Parkinson's disease. Nonetheless, the precise mechanisms explaining this pathogenic neuronal cell death remain elusive. Endonuclease G (EndoG) is a mitochondrially localized nuclease that triggers DNA degradation and cell death upon translocation from mitochondria to the nucleus. Here, we show that EndoG displays cytotoxic nuclear localization in dopaminergic neurons of human Parkinson-diseased patients, while EndoG depletion largely reduces α-synuclein-induced cell death in human neuroblastoma cells. Xenogenic expression of human α-synuclein in yeast cells triggers mitochondria-nuclear translocation of EndoG and EndoG-mediated DNA degradation through a mechanism that requires a functional kynurenine pathway and the permeability transition pore. In nematodes and flies, EndoG is essential for the α-synuclein-driven degeneration of dopaminergic neurons. Moreover, the locomotion and survival of α-synuclein-expressing flies is compromised, but reinstalled by parallel depletion of EndoG. In sum, we unravel a phylogenetically conserved pathway that involves EndoG as a critical downstream executor of α-synuclein cytotoxicity.

  14. Modeling tidal exchange and dispersion in Boston Harbor

    USGS Publications Warehouse

    Signell, Richard P.; Butman, Bradford

    1992-01-01

    Tidal dispersion and the horizontal exchange of water between Boston Harbor and the surrounding ocean are examined with a high-resolution (200 m) depth-averaged numerical model. The strongly varying bathymetry and coastline geometry of the harbor generate complex spatial patterns in the modeled tidal currents which are verified by shipboard acoustic Doppler surveys. Lagrangian exchange experiments demonstrate that tidal currents rapidly exchange and mix material near the inlets of the harbor due to asymmetry in the ebb/flood response. This tidal mixing zone extends roughly a tidal excursion from the inlets and plays an important role in the overall flushing of the harbor. Because the tides can only efficiently mix material in this limited region, however, harbor flushing must be considered a two step process: rapid exchange in the tidal mixing zone, followed by flushing of the tidal mixing zone by nontidal residual currents. Estimates of embayment flushing based on tidal calculations alone therefore can significantly overestimate the flushing time that would be expected under typical environmental conditions. Particle-release simulations from point sources also demonstrate that while the tides efficiently exchange material in the vicinity of the inlets, the exact nature of dispersion from point sources is extremely sensitive to the timing and location of the release, and the distribution of particles is streaky and patchlike. This suggests that high-resolution modeling of dispersion from point sources in these regions must be performed explicitly and cannot be parameterized as a plume with Gaussian-spreading in a larger scale flow field.

  15. 33 CFR 110.80b - Marquette Harbor, Marquette, Mich.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marquette Harbor, Marquette, Mich. 110.80b Section 110.80b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.80b Marquette Harbor, Marquette, Mich. The...

  16. 33 CFR 110.80b - Marquette Harbor, Marquette, Mich.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Marquette Harbor, Marquette, Mich. 110.80b Section 110.80b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.80b Marquette Harbor, Marquette, Mich. The...

  17. 33 CFR 110.80b - Marquette Harbor, Marquette, Mich.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Marquette Harbor, Marquette, Mich. 110.80b Section 110.80b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.80b Marquette Harbor, Marquette, Mich. The...

  18. 33 CFR 110.80b - Marquette Harbor, Marquette, Mich.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marquette Harbor, Marquette, Mich. 110.80b Section 110.80b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.80b Marquette Harbor, Marquette, Mich. The...

  19. 33 CFR 110.80b - Marquette Harbor, Marquette, Mich.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Marquette Harbor, Marquette, Mich. 110.80b Section 110.80b Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.80b Marquette Harbor, Marquette, Mich. The...

  20. 78 FR 42016 - Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, WI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-15

    ...-AA00 Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, WI AGENCY: Coast Guard, DHS... Milwaukee Harbor due to 4 fireworks displays at Discovery World Pier. This safety zone is necessary to... entitled, ``Safety Zone; Discovery World Fireworks, Milwaukee Harbor, Milwaukee, Wisconsin'' in the Federal...

  1. Multipronged regulatory functions of a novel endonuclease (TieA) from Helicobacter pylori

    PubMed Central

    Devi, Savita; Ansari, Suhail A.; Tenguria, Shivendra; Kumar, Naveen; Ahmed, Niyaz

    2016-01-01

    Helicobacter pylori portrays a classical paradigm of persistent bacterial infections. A well balanced homeostasis of bacterial effector functions and host responses is purported to be the key in achieving long term colonization in specific hosts. H. pylori nucleases have been shown to assist in natural transformation, but their role in virulence and colonization remains elusive. Therefore, it is imperative to understand the involvement of these nucleases in the pathogenesis of H. pylori. Here, we report the multifaceted role of a TNFR-1 interacting endonuclease A (TieA) from H. pylori. tieA expression is differentially regulated in response to environmental stress and post adherence to gastric epithelial cells. Studies with isogenic knockouts of tieA revealed it to be a secretory protein which translocates into the host gastric epithelial cells independent of a type IV secretion system, gets phosphorylated by DNA-PK kinase and auto-phosphorylates as serine kinase. Furthermore, TieA binds to and cleaves DNA in a non-specific manner and promotes Fas mediated apoptosis in AGS cells. Additionally, TieA induced pro-inflammatory cytokine secretion via activation of transcription factor AP-1 and signaled through MAP kinase pathway. Collectively, TieA with its multipronged and moonlighting functions could facilitate H. pylori in maintaining a balance of bacterial adaptation, and elimination by the host responses. PMID:27550181

  2. Phage T4 SegB protein is a homing endonuclease required for the preferred inheritance of T4 tRNA gene region occurring in co-infection with a related phage.

    PubMed

    Brok-Volchanskaya, Vera S; Kadyrov, Farid A; Sivogrivov, Dmitry E; Kolosov, Peter M; Sokolov, Andrey S; Shlyapnikov, Michael G; Kryukov, Valentine M; Granovsky, Igor E

    2008-04-01

    Homing endonucleases initiate nonreciprocal transfer of DNA segments containing their own genes and the flanking sequences by cleaving the recipient DNA. Bacteriophage T4 segB gene, which is located in a cluster of tRNA genes, encodes a protein of unknown function, homologous to homing endonucleases of the GIY-YIG family. We demonstrate that SegB protein is a site-specific endonuclease, which produces mostly 3' 2-nt protruding ends at its DNA cleavage site. Analysis of SegB cleavage sites suggests that SegB recognizes a 27-bp sequence. It contains 11-bp conserved sequence, which corresponds to a conserved motif of tRNA TpsiC stem-loop, whereas the remainder of the recognition site is rather degenerate. T4-related phages T2L, RB1 and RB3 contain tRNA gene regions that are homologous to that of phage T4 but lack segB gene and several tRNA genes. In co-infections of phages T4 and T2L, segB gene is inherited with nearly 100% of efficiency. The preferred inheritance depends absolutely on the segB gene integrity and is accompanied by the loss of the T2L tRNA gene region markers. We suggest that SegB is a homing endonuclease that functions to ensure spreading of its own gene and the surrounding tRNA genes among T4-related phages.

  3. Phage T4 SegB protein is a homing endonuclease required for the preferred inheritance of T4 tRNA gene region occurring in co-infection with a related phage

    PubMed Central

    Brok-Volchanskaya, Vera S.; Kadyrov, Farid A.; Sivogrivov, Dmitry E.; Kolosov, Peter M.; Sokolov, Andrey S.; Shlyapnikov, Michael G.; Kryukov, Valentine M.; Granovsky, Igor E.

    2008-01-01

    Homing endonucleases initiate nonreciprocal transfer of DNA segments containing their own genes and the flanking sequences by cleaving the recipient DNA. Bacteriophage T4 segB gene, which is located in a cluster of tRNA genes, encodes a protein of unknown function, homologous to homing endonucleases of the GIY-YIG family. We demonstrate that SegB protein is a site-specific endonuclease, which produces mostly 3′ 2-nt protruding ends at its DNA cleavage site. Analysis of SegB cleavage sites suggests that SegB recognizes a 27-bp sequence. It contains 11-bp conserved sequence, which corresponds to a conserved motif of tRNA TψC stem-loop, whereas the remainder of the recognition site is rather degenerate. T4-related phages T2L, RB1 and RB3 contain tRNA gene regions that are homologous to that of phage T4 but lack segB gene and several tRNA genes. In co-infections of phages T4 and T2L, segB gene is inherited with nearly 100% of efficiency. The preferred inheritance depends absolutely on the segB gene integrity and is accompanied by the loss of the T2L tRNA gene region markers. We suggest that SegB is a homing endonuclease that functions to ensure spreading of its own gene and the surrounding tRNA genes among T4-related phages. PMID:18281701

  4. Metal concentrations in surface sediments of Boston Harbor: Changes with time

    USGS Publications Warehouse

    Bothner, Michael H.; Buchholtz ten Brink, Marilyn R.; Manheim, F.T.

    1998-01-01

    The concentrations of metals in surface sediments of Boston Harbor have decreased during the period 1977–1993. This conclusion is supported by analysis of: (1) surface sediments collected at monitoring stations in the outer harbor between 1977 and 1993; (2) metal concentration profiles in sediment cores from depositional areas of the harbor; and (3) historical data from a contaminated-sediment database, which includes information on metal and organic contaminants and sediment texture. The background and matrix-corrected concentrations of lead (Pb) measured in the surficial layer (0–2 cm) of cores decreased by an average of 46%±12% among four locations in the outer harbor during the 16 y period. Chromium (Cr), copper (Cu), mercury (Hg), silver (Ag), and zinc (Zn) exhibited similar trends. Results from our sediment sampling are supported by historical data that were compiled from diverse sources into a regional sediment database. This sediment database contains approximately 3000 samples; of these, about 460 samples were collected and analyzed for Cu, Hg, or Zn and many other sediment parameters in Boston Harbor surface sediments between 1971–1993. The database indicates that the concentrations of these three metals also decreased with time in Boston’s Inner Harbor. The decreases in metal concentrations that are observed in more recent years parallel a general decrease in the flux of metals to the harbor, implemented by: (1) ending the sewage sludge discharge to the Harbor in December, 1991; (2) greater source reduction (e.g. recovery of silver from photographic processing) and closing or moving of industries; (3) improvements in wastewater handling and sewage treatment; and (4) diminishing use of lead in gasoline beginning about 1973. Despite the general decrease in metal concentrations in Boston Harbor surface sediments, the concentrations of Ag and Hg measured at some outer harbor stations in 1993 were still at, or above, the level associated with

  5. Antitumor activity of alectinib, a selective ALK inhibitor, in an ALK-positive NSCLC cell line harboring G1269A mutation: Efficacy of alectinib against ALK G1269A mutated cells.

    PubMed

    Yoshimura, Yasushi; Kurasawa, Mitsue; Yorozu, Keigo; Puig, Oscar; Bordogna, Walter; Harada, Naoki

    2016-03-01

    Alectinib is a highly selective next-generation anaplastic lymphoma kinase (ALK) inhibitor. Although alectinib shows inhibitory activity against various crizotinib-resistant ALK mutations in studies using cell-free kinase assays and Ba/F3 cell-based assays, it has not been tested for efficacy against non-small cell lung cancer (NSCLC) with the ALK mutations. We conducted in vitro and in vivo investigations into the antitumor activity of alectinib against an ALK-positive NSCLC cell line, SNU-2535, which harbors an ALK G1269A mutation. The clinical efficacy of alectinib against a NSCLC patient harboring ALK G1269A mutation was evaluated in the phase I part of the North American study. Alectinib exhibited antiproliferative activity against SNU-2535 cells in vitro with IC50 of 33.1 nM. Alectinib strongly inhibited phosphorylation of ALK and its downstream signaling molecules ERK1/2, AKT, and STAT3. In a mouse xenograft model, once-daily oral administration of alectinib for 21 days resulted in strong tumor regression. In addition, administration of alectinib for 100 days achieved continuous tumor regression without tumor regrowth in all mice. Notably, eradication of tumor cells was observed in half of the mice. In the clinical study, a patient with ALK G1269A mutation showed partial response to alectinib with a duration of response of 84 days. These results indicated that alectinib has potent antitumor activity against NSCLC cells harboring the crizotinib-resistant mutation ALK G1269A. It is expected that alectinib would provide a valuable therapeutic option for patients with NSCLC having not only native ALK but also crizotinib-resistant ALK mutations.

  6. Digital detection of endonuclease mediated gene disruption in the HIV provirus

    PubMed Central

    Sedlak, Ruth Hall; Liang, Shu; Niyonzima, Nixon; De Silva Feelixge, Harshana S.; Roychoudhury, Pavitra; Greninger, Alexander L.; Weber, Nicholas D.; Boissel, Sandrine; Scharenberg, Andrew M.; Cheng, Anqi; Magaret, Amalia; Bumgarner, Roger; Stone, Daniel; Jerome, Keith R.

    2016-01-01

    Genome editing by designer nucleases is a rapidly evolving technology utilized in a highly diverse set of research fields. Among all fields, the T7 endonuclease mismatch cleavage assay, or Surveyor assay, is the most commonly used tool to assess genomic editing by designer nucleases. This assay, while relatively easy to perform, provides only a semi-quantitative measure of mutation efficiency that lacks sensitivity and accuracy. We demonstrate a simple droplet digital PCR assay that quickly quantitates a range of indel mutations with detection as low as 0.02% mutant in a wild type background and precision (≤6%CV) and accuracy superior to either mismatch cleavage assay or clonal sequencing when compared to next-generation sequencing. The precision and simplicity of this assay will facilitate comparison of gene editing approaches and their optimization, accelerating progress in this rapidly-moving field. PMID:26829887

  7. 33 CFR 110.58 - Cos Cob Harbor, Greenwich, Conn.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Cos Cob Harbor, Greenwich, Conn. 110.58 Section 110.58 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.58 Cos Cob Harbor, Greenwich, Conn. (a) Area A...

  8. 33 CFR 110.58 - Cos Cob Harbor, Greenwich, Conn.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Cos Cob Harbor, Greenwich, Conn. 110.58 Section 110.58 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.58 Cos Cob Harbor, Greenwich, Conn. (a) Area A...

  9. 33 CFR 110.58 - Cos Cob Harbor, Greenwich, Conn.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Cos Cob Harbor, Greenwich, Conn. 110.58 Section 110.58 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.58 Cos Cob Harbor, Greenwich, Conn. (a) Area A...

  10. 33 CFR 110.58 - Cos Cob Harbor, Greenwich, Conn.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cos Cob Harbor, Greenwich, Conn. 110.58 Section 110.58 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.58 Cos Cob Harbor, Greenwich, Conn. (a) Area A...

  11. 33 CFR 110.58 - Cos Cob Harbor, Greenwich, Conn.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Cos Cob Harbor, Greenwich, Conn. 110.58 Section 110.58 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.58 Cos Cob Harbor, Greenwich, Conn. (a) Area A...

  12. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage grounds—(1...

  13. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage grounds—(1...

  14. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage grounds—(1...

  15. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage grounds—(1...

  16. 33 CFR 110.240 - San Juan Harbor, P.R.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false San Juan Harbor, P.R. 110.240 Section 110.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.240 San Juan Harbor, P.R. (a) The anchorage grounds—(1...

  17. 76 FR 32071 - Safety Zone; Conneaut Festival Fireworks, Conneaut Harbor, Conneaut, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ...-AA00 Safety Zone; Conneaut Festival Fireworks, Conneaut Harbor, Conneaut, OH AGENCY: Coast Guard, DHS... Conneaut Harbor, Conneaut, OH for the Conneaut Festival Fireworks. This zone is intended to restrict vessels from a portion of Conneaut Harbor, Conneaut, OH during the Conneaut Festival Fireworks on July 3...

  18. 76 FR 34865 - Safety Zone; Rochester Harbor Festival, Genesee River, Rochester, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-15

    ...-AA00 Safety Zone; Rochester Harbor Festival, Genesee River, Rochester, NY AGENCY: Coast Guard, DHS... Genesee River, Rochester, NY for the Rochester Harbor Festival fireworks. This zone is intended to restrict vessels from the mouth of the Genesee River in Rochester during the Rochester Harbor Festival...

  19. Ecological effects of rubble-mound breakwater construction and channel dredging at West Harbor, Ohio (western Lake Erie)

    USGS Publications Warehouse

    Manny, Bruce A.; Schloesser, Donald W.; Brown, Charles L.; French, John R. P.

    1985-01-01

    The investigation reported herein indicated that breakwater construction and associated channel dredging activities by the US Army Corps of Engineers in western Lake Erie at the entrance to West Harbor (Ohio) had no detectable adverse impacts on the distributions or abundances of macrozoobenthos and fishes. Rather, increases were noted in the number of fish eggs and larvae and in the density and biomass of periphyton and macrozoobenthos on and near the breakwaters. The area also served as a nursery ground for 20 species of fishes both during and after construction and dredging activities. Colonization of the breakwaters by periphyton, primarily a green alga (Cladophora glomerata), diatoms (Gomphonema parvulum), and a bluegreen alga (Oscillatoria tenuis), and by macrozoobenthos, primarily worms (Oligochaeta), amphipods (Gammarus spp.), and midge larvae (Chironomidae), was rapid and extensive, indicating that the breakwaters provided new, favorable habitat for primary and secondary producer organisms. Marked adverse changes in water quality, especially reduced dissolved oxygen concentrations (25 mg/l), occurred around the entrance to West Harbor in 1983 following cessation of construction and dredging activities. These water quality changes, however, could not be ascribed with certainty to construction and dredging activities at West Harbor. Construction of additional breakwaters in the study area at that time by the State of Ohio served to confound determination of the responsible causal factors.

  20. Los Angeles Beach Harbors, Los Angeles County, California.

    DTIC Science & Technology

    1974-10-01

    predicted at this time. The presently proposed project is not dependent upon nor contributory to further navigation development in the V" Los Angeles...as Long Beach and Compton. The Los Angeles Harbor probably exhibited similar intensities ranging from VII to IX depending on the soil conditions...the harbor. The water quality in these aquifers is dependent upon the rates of recharge and extraction (natural and otherwise). The Dominguez Gap

  1. Butyltin Concentrations in Selected US Harbor Systems. A Baseline Assessment.

    DTIC Science & Technology

    1987-04-01

    and the Naval Supply Center. Additionally. San Diego Bay is a multiple-use region that supports a commercial port, private shipyards, recreational...are Naval Air Station, Alameda; Naval Supply Center, Oakland: and Naval Station. Treasure Island. The Naval Support Activity at Mare Island is also...terminal on the west coast. The port is divided into three sections (figure 3). The Oakland Outer Harbor is situated to the north of the Naval Supply

  2. 78 FR 28619 - Boston Harbor Islands Advisory Council Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-15

    ... DEPARTMENT OF THE INTERIOR [NPS-NER-BOHA-12921: PPMPSPD1Z.YM0000: PPNEBOHAS1] Boston Harbor.... SUMMARY: This notice announces a meeting of the Boston Harbor Islands Advisory Council. The agenda... park update. DATES: Date/Time: June 5, 2013, 4:00 p.m. to 6:00 p.m. (EASTERN). Location: Boston Society...

  3. 26 CFR 1.401(k)-3 - Safe harbor requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Safe harbor requirements. 1.401(k)-3 Section 1.401(k)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(k)-3 Safe harbor...

  4. 26 CFR 1.401(m)-3 - Safe harbor requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Safe harbor requirements. 1.401(m)-3 Section 1.401(m)-3 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.401(m)-3 Safe harbor...

  5. DNA and Protein Requirements for Substrate Conformational Changes Necessary for Human Flap Endonuclease-1-catalyzed Reaction*

    PubMed Central

    Algasaier, Sana I.; Exell, Jack C.; Bennet, Ian A.; Thompson, Mark J.; Gotham, Victoria J. B.; Shaw, Steven J.; Craggs, Timothy D.; Finger, L. David; Grasby, Jane A.

    2016-01-01

    Human flap endonuclease-1 (hFEN1) catalyzes the essential removal of single-stranded flaps arising at DNA junctions during replication and repair processes. hFEN1 biological function must be precisely controlled, and consequently, the protein relies on a combination of protein and substrate conformational changes as a prerequisite for reaction. These include substrate bending at the duplex-duplex junction and transfer of unpaired reacting duplex end into the active site. When present, 5′-flaps are thought to thread under the helical cap, limiting reaction to flaps with free 5′-termini in vivo. Here we monitored DNA bending by FRET and DNA unpairing using 2-aminopurine exciton pair CD to determine the DNA and protein requirements for these substrate conformational changes. Binding of DNA to hFEN1 in a bent conformation occurred independently of 5′-flap accommodation and did not require active site metal ions or the presence of conserved active site residues. More stringent requirements exist for transfer of the substrate to the active site. Placement of the scissile phosphate diester in the active site required the presence of divalent metal ions, a free 5′-flap (if present), a Watson-Crick base pair at the terminus of the reacting duplex, and the intact secondary structure of the enzyme helical cap. Optimal positioning of the scissile phosphate additionally required active site conserved residues Tyr40, Asp181, and Arg100 and a reacting duplex 5′-phosphate. These studies suggest a FEN1 reaction mechanism where junctions are bound and 5′-flaps are threaded (when present), and finally the substrate is transferred onto active site metals initiating cleavage. PMID:26884332

  6. Pulmonary inflammatory myofibroblastic tumor harboring EML4-ALK fusion gene.

    PubMed

    Sokai, Akihiko; Enaka, Makiko; Sokai, Risa; Mori, Shoichi; Mori, Shunsuke; Gunji, Masaharu; Fujino, Masahiko; Ito, Masafumi

    2014-01-01

    Inflammatory myofibroblastic tumor is a rare tumor deriving from mesenchymal tissue. Approximately 50% of inflammatory myofibroblastic tumors harbor an anaplastic lymphoma kinase fusion gene. Pulmonary inflammatory myofibroblastic tumors harboring tropomyosin3-anaplastic lymphoma kinase or protein tyrosine phosphatase receptor-type F polypeptide-interacting protein-binding protein 1-anaplastic lymphoma kinase have been reported previously. However, it has not been reported that inflammatory myofibroblastic tumors harbor echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene which is considered to be very specific to lung cancers. A few tumors harboring echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene other than lung cancers have been reported and the tumors were all carcinomas. A 67-year-old man had been followed up for a benign tumor for approximately 3 years before the tumor demonstrated malignant transformation. Lobectomy and autopsy revealed that an inflammatory myofibroblastic tumor harboring echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion gene had transformed into an undifferentiated sarcoma. This case suggests that echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase fusion is an oncogenic event in not only carcinomas but also sarcomas originating from stromal cells.

  7. Phosphate steering by Flap Endonuclease 1 promotes 5'-flap specificity and incision to prevent genome instability

    DOE PAGES

    Tsutakawa, Susan E.; Thompson, Mark J.; Arvai, Andrew S.; ...

    2017-06-27

    DNA replication and repair enzyme Flap Endonuclease 1 (FEN1) is vital for genome integrity, and FEN1 mutations arise in multiple cancers. FEN1 precisely cleaves single-stranded (ss) 5'-flaps one nucleotide into duplex (ds) DNA. Yet, how FEN1 selects for but does not incise the ss 5'-flap was enigmatic. Here we combine crystallographic, biochemical and genetic analyses to show that two dsDNA binding sites set the 5'polarity and to reveal unexpected control of the DNA phosphodiester backbone by electrostatic interactions. Via phosphate steering', basic residues energetically steer an inverted ss 5'-flap through a gateway over FEN1's active site and shift dsDNA formore » catalysis. Mutations of these residues cause an 18,000-fold reduction in catalytic rate in vitro and large-scale trinucleotide (GAA) n repeat expansions in vivo, implying failed phosphate-steering promotes an unanticipated lagging-strand template-switch mechanism during replication. Thus, phosphate steering is an unappreciated FEN1 function that enforces 5'-flap specificity and catalysis, preventing genomic instability.« less

  8. Phosphate steering by Flap Endonuclease 1 promotes 5'-flap specificity and incision to prevent genome instability

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

    Tsutakawa, Susan E.; Thompson, Mark J.; Arvai, Andrew S.

    DNA replication and repair enzyme Flap Endonuclease 1 (FEN1) is vital for genome integrity, and FEN1 mutations arise in multiple cancers. FEN1 precisely cleaves single-stranded (ss) 5'-flaps one nucleotide into duplex (ds) DNA. Yet, how FEN1 selects for but does not incise the ss 5'-flap was enigmatic. Here we combine crystallographic, biochemical and genetic analyses to show that two dsDNA binding sites set the 5'polarity and to reveal unexpected control of the DNA phosphodiester backbone by electrostatic interactions. Via phosphate steering', basic residues energetically steer an inverted ss 5'-flap through a gateway over FEN1's active site and shift dsDNA formore » catalysis. Mutations of these residues cause an 18,000-fold reduction in catalytic rate in vitro and large-scale trinucleotide (GAA) n repeat expansions in vivo, implying failed phosphate-steering promotes an unanticipated lagging-strand template-switch mechanism during replication. Thus, phosphate steering is an unappreciated FEN1 function that enforces 5'-flap specificity and catalysis, preventing genomic instability.« less

  9. Adenomatous Polyposis Coli Interacts with Flap Endonuclease 1 to Block Its Nuclear Entry and Function1

    PubMed Central

    Jaiswal, Aruna S; Armas, Melissa L; Izumi, Tadahide; Strauss, Phyllis R; Narayan, Satya

    2012-01-01

    In previous studies, we found that adenomatous polyposis coli (APC) blocks the base excision repair (BER) pathway by interacting with 5′-flap endonuclease 1 (Fen1). In this study, we identify the molecular features that contribute to the formation and/or stabilization of the APC/Fen1 complex that determines the extent of BER inhibition, and the subsequent accumulation of DNA damage creates mutagenic lesions leading to transformation susceptibility. We show here that APC binds to the nuclear localization sequence of Fen1 (Lys365Lys366Lys367), which prevents entry of Fen1 into the nucleus and participation in Pol-β-directed long-patch BER. We also show that levels of the APC/Fen1 complex are higher in breast tumors than in the surrounding normal tissues. These studies demonstrate a novel role for APC in the suppression of Fen1 activity in the BER pathway and a new biomarker profile to be explored to identify individuals who may be susceptible to the development of mammary and other tumors. PMID:22787431

  10. Remembering Pearl Harbor at 75 Years.

    PubMed

    Liehr, Patricia; Sopcheck, Janet; Milbrath, Gwyneth

    2016-12-01

    : On December 7, 1941, the Sunday-morning quiet of the U.S. naval base in Pearl Harbor, Hawaii, was shattered by dive-bombing Japanese fighter planes. The planes came in two waves-and when it was all over, more than 2,400 were killed and more than 1,100 were injured.Nurses were stationed at U.S. Naval Hospital Pearl Harbor, Tripler General Hospital (now Tripler Army Medical Center), Hickam Field Hospital, Schofield Barracks Station Hospital, and aboard the USS Solace, and witnessed the devastation. But they also did what nurses do in emergencies-they responded and provided care to those in need. Here are the stories of a few of those nurses.

  11. 77 FR 27666 - Proposed Amendment of Class E Airspace; Bar Harbor, ME

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ...-1366; Airspace Docket No. 11-ANE-13] Proposed Amendment of Class E Airspace; Bar Harbor, ME AGENCY... action proposes to amend Class E Airspace at Bar Harbor, ME, as the Surry Non-Directional Radio Beacon... Airport, Bar Harbor, ME. Airspace reconfiguration is necessary due to the decommissioning of the Surry NDB...

  12. 33 CFR 165.14-1414 - Safety Zones; Hawaiian Islands Commercial Harbors; HI.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... harbors, or all of these harbors, dependent upon details in the tsunami warning. These safety zones extend... period. Paragraph (b) of this section will be enforced when a tsunami warning has been issued for the... Coast Guard's Homeport Web site. Following the passage of the tsunami or tsunami threat and harbor...

  13. 78 FR 669 - Safety Zone; Hampton Harbor Channel Obstruction, Hampton Harbor; Hampton, NH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-04

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket Number USCG-2012-1055] RIN... docket [USCG-2012-1055]. To view documents mentioned in this preamble as being available in the docket....1. 0 2. Add Sec. 165.T01-1055 to read as follows: Sec. 165.T01-1055 Safety Zone; Hampton Harbor...

  14. Integrated approach to assess ecosystem health in harbor areas.

    PubMed

    Bebianno, M J; Pereira, C G; Rey, F; Cravo, A; Duarte, D; D'Errico, G; Regoli, F

    2015-05-01

    Harbors are critical environments with strategic economic importance but with potential environmental impact: health assessment criteria are a key issue. An ecosystem health status approach was carried out in Portimão harbor as a case-study. Priority and specific chemical levels in sediments along with their bioavailability in mussels, bioassays and a wide array of biomarkers were integrated in a biomarker index (IBR index) and the overall data in a weight of evidence (WOE) model. Metals, PAHs, PCBs and HCB were not particularly high compared with sediment guidelines and standards for dredging. Bioavailability was evident for Cd, Cu and Zn. Biomarkers proved more sensitive namely changes of antioxidant responses, metallothioneins and vittellogenin-like proteins. IBR index indicated that site 4 was the most impacted area. Assessment of the health status by WOE approach highlighted the importance of integrating sediment chemistry, bioaccumulation, biomarkers and bioassays and revealed that despite some disturbance in the harbor area, there was also an impact of urban effluents from upstream. Environmental quality assessment in harbors. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. 77 FR 43513 - Olympia Harbor Days Tug Boat Races, Budd Inlet, WA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-25

    ... Harbor Days Tug Boat Races, Budd Inlet, WA AGENCY: Coast Guard, DHS. ACTION: Notice of enforcement of regulation. SUMMARY: The Coast Guard will enforce the Special Local Regulation, Olympia Harbor Days Tug Boat... Special Local Regulation for Olympia Harbor Days Tug Boat Races, Budd Inlet, WA in 33 CFR 100.1309 on...

  16. Safe harbor: protecting ports with shipboard fuel cells.

    PubMed

    Taylor, David A

    2006-04-01

    With five of the largest harbors in the United States, California is beginning to take steps to manage the large amounts of pollution generated by these bustling centers of transport and commerce. One option for reducing diesel emissions is the use of fuel cells, which run cleaner than diesel and other internal combustion engines. Other technologies being explored by harbor officials are diesel-electric hybrid and gas turbine locomotives for moving freight within port complexes.

  17. 15. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, LOOKING OUT TOWARD ARIZONA MEMORIAL AND FORD ISLAND. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

  18. Roles for the Rad27 Flap Endonuclease in Mitochondrial Mutagenesis and Double-Strand Break Repair in Saccharomyces cerevisiae.

    PubMed

    Nagarajan, Prabha; Prevost, Christopher T; Stein, Alexis; Kasimer, Rachel; Kalifa, Lidza; Sia, Elaine A

    2017-06-01

    The structure-specific nuclease, Rad27p/FEN1, plays a crucial role in DNA repair and replication mechanisms in the nucleus. Genetic assays using the rad27-∆ mutant have shown altered rates of DNA recombination, microsatellite instability, and point mutation in mitochondria. In this study, we examined the role of Rad27p in mitochondrial mutagenesis and double-strand break (DSB) repair in Saccharomyces cerevisiae Our findings show that Rad27p is essential for efficient mitochondrial DSB repair by a pathway that generates deletions at a region flanked by direct repeat sequences. Mutant analysis suggests that both exonuclease and endonuclease activities of Rad27p are required for its role in mitochondrial DSB repair. In addition, we found that the nuclease activities of Rad27p are required for the prevention of mitochondrial DNA (mtDNA) point mutations, and in the generation of spontaneous mtDNA rearrangements. Overall, our findings underscore the importance of Rad27p in the maintenance of mtDNA, and demonstrate that it participates in multiple DNA repair pathways in mitochondria, unlinked to nuclear phenotypes. Copyright © 2017 by the Genetics Society of America.

  19. Charleston Harbor Deepening Project. Charleston Harbor and Shipyard River, South Carolina.

    DTIC Science & Technology

    1976-04-01

    between the two basins to 250 feet; enlargement of the 0 anchorage basin near the harbor mouth by deepening to a depth of 40 feet and by extending the...and 0 Wando River; and the relocating of channels near terminals to provide 125-foot clearance between piers and the edge of the channel. * 0 0...materials; localized adverse effects on plankton and primary productivity; minor losses of larval and juvenile fishes near the dredge and disposal areas

  20. Occurrence of fungi in combs of fungus-growing termites (Isoptera: Termitidae, Macrotermitinae).

    PubMed

    Guedegbe, Herbert J; Miambi, Edouard; Pando, Anne; Roman, Jocelyne; Houngnandan, Pascal; Rouland-Lefevre, Corinne

    2009-10-01

    Fungus-growing termites cultivate their mutualistic basidiomycete Termitomyces species on a substrate called a fungal comb. Here, the Suicide Polymerase Endonuclease Restriction (SuPER) method was adapted for the first time to a fungal study to determine the entire fungal community of fungal combs and to test whether fungi other than the symbiotic cultivar interact with termite hosts. Our molecular analyses show that although active combs are dominated by Termitomyces fungi isolated with direct Polymerase Endonuclease Restriction - Denaturing Gradient Gel Electrophoresis (PCR-DGGE), they can also harbor some filamentous fungi and yeasts only revealed by SuPER PCR-DGGE. This is the first molecular evidence of the presence of non-Termitomyces species in active combs. However, because there is no evidence for a species-specific relationship between these fungi and termites, they are mere transient guests with no specialization in the symbiosis. It is however surprising to notice that termite-associated Xylaria strains were not isolated from active combs even though they are frequently retrieved when nests are abandoned by termites. This finding highlights the implication of fungus-growing termites in the regulation of fungi occurring within the combs and also suggests that they might not have any particular evolutionary-based association with Xylaria species.

  1. Preliminary Feasibility Report Stage II, Lorain Small-Boat Harbor, Lorain, Ohio. Revision.

    DTIC Science & Technology

    1982-03-01

    effects of each alternative plan. Activities consist of analyzing each measure to deter- mine potential sources , the incidence, and the magni- tude...using existing reports, available data sources , visual inspections, onsite interviews, and workshop discussions. Alternative small-boat harbor designs...were developed to a consistent level of detail. Prior reports were used as data sources for preliminary design of break- waters, including length

  2. U.S. Naval Base, Pearl Harbor, Red Hill Underground Fuel Storage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    U.S. Naval Base, Pearl Harbor, Red Hill Underground Fuel Storage System, Linear underground system extending from North Road to Icarus Way, Joint Base Pearl Harbor-Hickam, Honolulu, Honolulu County, HI

  3. 33 CFR 110.214 - Los Angeles and Long Beach harbors, California.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... following locations: (A) Inner Harbor: The Henry Ford (Badger Avenue) Bridge. (B) Middle Harbor: The Pier... will be given, but not necessarily limited to: the current and anticipated demands for anchorage space...

  4. 33 CFR 110.214 - Los Angeles and Long Beach harbors, California.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... following locations: (A) Inner Harbor: The Henry Ford (Badger Avenue) Bridge. (B) Middle Harbor: The Pier... will be given, but not necessarily limited to: the current and anticipated demands for anchorage space...

  5. Harbor seal vibrissa morphology suppresses vortex-induced vibrations.

    PubMed

    Hanke, Wolf; Witte, Matthias; Miersch, Lars; Brede, Martin; Oeffner, Johannes; Michael, Mark; Hanke, Frederike; Leder, Alfred; Dehnhardt, Guido

    2010-08-01

    Harbor seals (Phoca vitulina) often live in dark and turbid waters, where their mystacial vibrissae, or whiskers, play an important role in orientation. Besides detecting and discriminating objects by direct touch, harbor seals use their whiskers to analyze water movements, for example those generated by prey fish or by conspecifics. Even the weak water movements left behind by objects that have passed by earlier can be sensed and followed accurately (hydrodynamic trail following). While scanning the water for these hydrodynamic signals at a swimming speed in the order of meters per second, the seal keeps its long and flexible whiskers in an abducted position, largely perpendicular to the swimming direction. Remarkably, the whiskers of harbor seals possess a specialized undulated surface structure, the function of which was, up to now, unknown. Here, we show that this structure effectively changes the vortex street behind the whiskers and reduces the vibrations that would otherwise be induced by the shedding of vortices from the whiskers (vortex-induced vibrations). Using force measurements, flow measurements and numerical simulations, we find that the dynamic forces on harbor seal whiskers are, by at least an order of magnitude, lower than those on sea lion (Zalophus californianus) whiskers, which do not share the undulated structure. The results are discussed in the light of pinniped sensory biology and potential biomimetic applications.

  6. Lorain Harbor, Ohio. Preliminary Feasibility Study (Stage 2). Review of Reports. Volume II. Appendices.

    DTIC Science & Technology

    1980-10-01

    looked all the way from the west to all the way down to Erie , Pennsylvania . We made some initial cuts and got it down to five different ports...Harbor, MN Presque Isle :Two Harbors, MN :Gary, IN 1,721,920 25 (Litton Great Lakes):Two Harbors, MN :Calumet Harbor, IN 178,080 3 :Two Harbors, MN...WI : 2 :11 : 0: 0 : 0: 2: 3 Silver Bay, MN : 82 :67 : 96 :87 : 85 : 88: 89 Taconite, MN : 0 : 0 : 0: 0 : 0: 4: 0 Presque Isle , MI : 6 2 : 1 0.5: 2 1

  7. Frequency Domain Response at Pacific Coast Harbors to Major Tsunamis of 2005-2011

    NASA Astrophysics Data System (ADS)

    Xing, Xiuying; Kou, Zhiqing; Huang, Ziyi; Lee, Jiin-Jen

    2013-06-01

    Tsunamis waves caused by submarine earthquake or landslide might contain large wave energy, which could cause significant human loss and property damage locally as well as in distant region. The response of three harbors located at the Pacific coast (i.e. Crescent City Harbor, Los Angeles/Long Beach Port, and San Diego Harbor) to six well-known tsunamis events generated (both near-field and far-field) between 2005 and 2011 are examined and simulated using a hybrid finite element numerical model in frequency domain. The model incorporated the effects of wave refraction, wave diffraction, partial wave reflection from boundaries, entrance and bottom energy dissipation. It can be applied to harbor regions with arbitrary shapes and variable water depth. The computed resonant periods or modes of oscillation for three harbors are in good agreement with the energy spectral analysis of the time series of water surface elevations recorded at tide gauge stations inside three harbors during the six tsunamis events. The computed wave induced currents based on the present model are also in qualitative agreement with some of the reported eye-witness accounts absence of reliable current data. The simulated results show that each harbor responded differently and significantly amplified certain wave period(s) of incident wave trains according to the shape, topography, characteristic dimensions and water depth of the harbor basins.

  8. 33 CFR 110.40 - Silver Beach Harbor, North Falmouth, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Silver Beach Harbor, North Falmouth, Mass. 110.40 Section 110.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.40 Silver Beach Harbor, North...

  9. 33 CFR 110.40 - Silver Beach Harbor, North Falmouth, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Silver Beach Harbor, North Falmouth, Mass. 110.40 Section 110.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.40 Silver Beach Harbor, North...

  10. 33 CFR 110.40 - Silver Beach Harbor, North Falmouth, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Silver Beach Harbor, North Falmouth, Mass. 110.40 Section 110.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.40 Silver Beach Harbor, North...

  11. 33 CFR 110.40 - Silver Beach Harbor, North Falmouth, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Silver Beach Harbor, North Falmouth, Mass. 110.40 Section 110.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.40 Silver Beach Harbor, North...

  12. 33 CFR 110.40 - Silver Beach Harbor, North Falmouth, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Silver Beach Harbor, North Falmouth, Mass. 110.40 Section 110.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.40 Silver Beach Harbor, North...

  13. 16. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. TYPICAL VIEW OF PEARL HARBOR FROM SIGNAL TOWER OFFICE, LOOKING OUT AT MAIN CHANNEL ENTRANCE, WITH FORD ISLAND ON THE RIGHT. - U.S. Naval Base, Pearl Harbor, Signal Tower, Corner of Seventh Street & Avenue D east of Drydock No. 1, Pearl City, Honolulu County, HI

  14. ERCC1-XPF Endonuclease Facilitates DNA Double-Strand Break Repair▿ †

    PubMed Central

    Ahmad, Anwaar; Robinson, Andria Rasile; Duensing, Anette; van Drunen, Ellen; Beverloo, H. Berna; Weisberg, David B.; Hasty, Paul; Hoeijmakers, Jan H. J.; Niedernhofer, Laura J.

    2008-01-01

    ERCC1-XPF endonuclease is required for nucleotide excision repair (NER) of helix-distorting DNA lesions. However, mutations in ERCC1 or XPF in humans or mice cause a more severe phenotype than absence of NER, prompting a search for novel repair activities of the nuclease. In Saccharomyces cerevisiae, orthologs of ERCC1-XPF (Rad10-Rad1) participate in the repair of double-strand breaks (DSBs). Rad10-Rad1 contributes to two error-prone DSB repair pathways: microhomology-mediated end joining (a Ku86-independent mechanism) and single-strand annealing. To determine if ERCC1-XPF participates in DSB repair in mammals, mutant cells and mice were screened for sensitivity to gamma irradiation. ERCC1-XPF-deficient fibroblasts were hypersensitive to gamma irradiation, and γH2AX foci, a marker of DSBs, persisted in irradiated mutant cells, consistent with a defect in DSB repair. Mutant mice were also hypersensitive to irradiation, establishing an essential role for ERCC1-XPF in protecting against DSBs in vivo. Mice defective in both ERCC1-XPF and Ku86 were not viable. However, Ercc1−/− Ku86−/− fibroblasts were hypersensitive to gamma irradiation compared to single mutants and accumulated significantly greater chromosomal aberrations. Finally, in vitro repair of DSBs with 3′ overhangs led to large deletions in the absence of ERCC1-XPF. These data support the conclusion that, as in yeast, ERCC1-XPF facilitates DSB repair via an end-joining mechanism that is Ku86 independent. PMID:18541667

  15. Peculiarities of Crystallization of the Restriction Endonuclease EcoRII

    NASA Technical Reports Server (NTRS)

    Karpove, Elizaveta; Pusey, M.arc L.

    1998-01-01

    Nucleases interfere with most standard molecular biology procedures. We have purified and crystallized the restriction endonuclease EcoRII, which belongs to the type II of restriction- modification enzyme, to study the protein crystallization process using a "non standard" macromolecule. A procedure for the purification of EcoRII was developed and 99% pure protein as determined by SDS PAGE electrophoresis obtained. Light scattering experiments were performed to assist in screening protein suitable crystallization conditions. The second virial coefficient was determined as a function of precipitating salt concentration, using sodium chloride, ammonium sulfate, and sodium sulfate. Small (maximum size approximately 0.2 mm) well shaped crystals have been obtained. Larger poorly formed crystals (ca 0.5 mm) have also been obtained, but we have been unable to mount them for diff-raction analysis due to their extreme fragility. Crystallization experiments with PEG have shown that using this precipitant, the best crystals are obtained from slightly over-saturated solutions. Use of higher precipitant concentration leads to dendritic crystal formation. EcoRII is difficult to solubilize and meticulous attention must be paid to the presence of reducing agents.

  16. 78 FR 18479 - Drawbridge Operation Regulations; Inner Harbor Navigation Canal, New Orleans, LA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... Operation Regulations; Inner Harbor Navigation Canal, New Orleans, LA AGENCY: Coast Guard, DHS. ACTION... across the Inner Harbor Navigation Canal, mile 4.6, at New Orleans, Louisiana. This deviation is... Seabrook Highway crossing the Inner Harbor Navigation Canal, mile 4.6, in New Orleans, Louisiana. The...

  17. Hydraulic modeling of stream channels and structures in Harbor and Crow Hollow Brooks, Meriden, Connecticut

    USGS Publications Warehouse

    Weiss, Lawrence A.; Sears, Michael P.; Cervione, Michael A.

    1994-01-01

    Effects of urbanization have increased the frequency and size of floods along certain reaches of Harbor Brook and Crow Hollow Brook in Meriden, Conn. A floodprofile-modeling study was conducted to model the effects of selected channel and structural modifications on flood elevations and inundated areas. The study covered the reach of Harbor Brook downstream from Interstate 691 and the reach of Crow Hollow Brook downstream from Johnson Avenue. Proposed modifications, which include changes to bank heights, channel geometry, structural geometry, and streambed armoring on Harbor Brook and changes to bank heights on Crow Hollow Brook, significantly lower flood elevations. Results of the modeling indicate a significant reduction of flood elevations for the 10-year, 25-year, 35-year, 50-year, and 100-year flood frequencies using proposed modifications to (1 ) bank heights between Harbor Brook Towers and Interstate 691 on Harbor Brook, and between Centennial Avenue and Johnson Avenue on Crow Hollow Brook; (2) channel geometry between Coe Avenue and Interstate 69 1 on Harbor Brook; (3) bridge and culvert opening geometry between Harbor Brook Towers and Interstate 691 on Harbor Brook; and (4) channel streambed armoring between Harbor Brook Towers and Interstate 691 on Harbor Brook. The proposed modifications were developed without consideration of cost-benefit ratios.

  18. 78 FR 63381 - Safety Zones; Hawaiian Island Commercial Harbors, HI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-24

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 165 [Docket No. USCG-2013-0021] RIN 1625-AA00 Safety Zones; Hawaiian Island Commercial Harbors, HI AGENCY: Coast Guard, DHS. ACTION: Final rule... as follows: Sec. 165. 14-1414 Safety Zones; Hawaiian Islands Commercial Harbors; HI. (a) Location...

  19. 33 CFR 162.110 - Duluth-Superior Harbor, Minnesota and Wisconsin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Duluth-Superior Harbor, Minnesota and Wisconsin. 162.110 Section 162.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Duluth-Superior Harbor, Minnesota and Wisconsin. (a) No vessel greater than 100 feet in length may exceed...

  20. 33 CFR 162.110 - Duluth-Superior Harbor, Minnesota and Wisconsin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Duluth-Superior Harbor, Minnesota and Wisconsin. 162.110 Section 162.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Duluth-Superior Harbor, Minnesota and Wisconsin. (a) No vessel greater than 100 feet in length may exceed...

  1. 33 CFR 162.110 - Duluth-Superior Harbor, Minnesota and Wisconsin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Duluth-Superior Harbor, Minnesota and Wisconsin. 162.110 Section 162.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Duluth-Superior Harbor, Minnesota and Wisconsin. (a) No vessel greater than 100 feet in length may exceed...

  2. 33 CFR 162.110 - Duluth-Superior Harbor, Minnesota and Wisconsin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Duluth-Superior Harbor, Minnesota and Wisconsin. 162.110 Section 162.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Duluth-Superior Harbor, Minnesota and Wisconsin. (a) No vessel greater than 100 feet in length may exceed...

  3. 33 CFR 162.110 - Duluth-Superior Harbor, Minnesota and Wisconsin.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Duluth-Superior Harbor, Minnesota and Wisconsin. 162.110 Section 162.110 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Duluth-Superior Harbor, Minnesota and Wisconsin. (a) No vessel greater than 100 feet in length may exceed...

  4. 33 CFR 110.77a - Duluth-Superior Harbor, Duluth, Minn.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Duluth-Superior Harbor, Duluth, Minn. 110.77a Section 110.77a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77a Duluth-Superior Harbor, Duluth...

  5. 33 CFR 110.77a - Duluth-Superior Harbor, Duluth, Minn.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Duluth-Superior Harbor, Duluth, Minn. 110.77a Section 110.77a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77a Duluth-Superior Harbor, Duluth...

  6. 33 CFR 110.77a - Duluth-Superior Harbor, Duluth, Minn.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Duluth-Superior Harbor, Duluth, Minn. 110.77a Section 110.77a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77a Duluth-Superior Harbor, Duluth...

  7. 33 CFR 110.77a - Duluth-Superior Harbor, Duluth, Minn.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Duluth-Superior Harbor, Duluth, Minn. 110.77a Section 110.77a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77a Duluth-Superior Harbor, Duluth...

  8. 33 CFR 110.77a - Duluth-Superior Harbor, Duluth, Minn.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Duluth-Superior Harbor, Duluth, Minn. 110.77a Section 110.77a Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.77a Duluth-Superior Harbor, Duluth...

  9. 19. Photocopy of Blueprint (Original blueprint located in Grays Harbor ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. Photocopy of Blueprint (Original blueprint located in Grays Harbor County Bridge File No. 4731/0.5 COAST BRIDGE COMPANY'S CONSTRUCTION BLUEPRINT OF 'FLOOR SYSTEM FOR 120' RIVETED SPAN' DATED JULY 1915 - West Wishkah Bridge, West Wishkah Road Spanning Wishkah River Middle Fork, Aberdeen, Grays Harbor County, WA

  10. Multipronged regulatory functions of a novel endonuclease (TieA) from Helicobacter pylori.

    PubMed

    Devi, Savita; Ansari, Suhail A; Tenguria, Shivendra; Kumar, Naveen; Ahmed, Niyaz

    2016-11-02

    Helicobacter pylori portrays a classical paradigm of persistent bacterial infections. A well balanced homeostasis of bacterial effector functions and host responses is purported to be the key in achieving long term colonization in specific hosts. H. pylori nucleases have been shown to assist in natural transformation, but their role in virulence and colonization remains elusive. Therefore, it is imperative to understand the involvement of these nucleases in the pathogenesis of H. pylori Here, we report the multifaceted role of a TNFR-1 interacting endonuclease A (TieA) from H. pylori. tieA expression is differentially regulated in response to environmental stress and post adherence to gastric epithelial cells. Studies with isogenic knockouts of tieA revealed it to be a secretory protein which translocates into the host gastric epithelial cells independent of a type IV secretion system, gets phosphorylated by DNA-PK kinase and auto-phosphorylates as serine kinase. Furthermore, TieA binds to and cleaves DNA in a non-specific manner and promotes Fas mediated apoptosis in AGS cells. Additionally, TieA induced pro-inflammatory cytokine secretion via activation of transcription factor AP-1 and signaled through MAP kinase pathway. Collectively, TieA with its multipronged and moonlighting functions could facilitate H. pylori in maintaining a balance of bacterial adaptation, and elimination by the host responses. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. 33 CFR 117.458 - Inner Harbor Navigation Canal, New Orleans.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Inner Harbor Navigation Canal, New Orleans. 117.458 Section 117.458 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Harbor Navigation Canal, New Orleans. (a) The draws of the SR 46 (St. Claude Avenue) bridge, mile 0.5...

  12. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  13. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  14. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  15. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  16. 33 CFR 117.1083 - Duluth-Superior Harbor (St. Louis River).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Duluth-Superior Harbor (St. Louis River). 117.1083 Section 117.1083 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...-Superior Harbor (St. Louis River). (a) The draws of the Burlington Northern railroad bridge, mile 5.7 at...

  17. 33 CFR 117.661 - Duluth Ship Canal (Duluth-Superior Harbor).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Duluth Ship Canal (Duluth-Superior Harbor). 117.661 Section 117.661 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF... Ship Canal (Duluth-Superior Harbor). The draw of the Duluth Ship Canal Aerial bridge, mile 0.25 at...

  18. 33 CFR 110.27 - Lynn Harbor in Broad Sound, Mass.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lynn Harbor in Broad Sound, Mass. 110.27 Section 110.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.27 Lynn Harbor in Broad Sound, Mass. North of...

  19. DINOFLAGELLATE CYST RECORD AND HUMAN DISTURBANCE IN NEW BEDFORD HARBOR, MA AND NARRAGANSETT BAY ESTUARIES

    EPA Science Inventory

    We studied the dinoflagellate cyst records in sediments from New Bedford Harbor and Apponagansett Bay over the last 350 yr provides to determine if cysts are sensitive to environmental change caused by human activity in the watershed. Changes in the total number, and absolute and...

  20. Boston Harbor National Park Service sites : alternative transportation systems evaluation report

    DOT National Transportation Integrated Search

    2001-06-01

    This project puts forth a forward looking water-based transportation plan which would serve four NPS units in and around Boston Harbor: Boston Harbor Islands National Recreation Area, Boston National Historical Park, Salem Maritime Historic Site, and...

  1. 33 CFR 110.250 - St. Thomas Harbor, Charlotte Amalie, V.I.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., V.I. (a) The anchorage grounds—(1) Inner harbor anchorage. Beginning at a point bearing 85°, 525... shall also be used by vessels having drafts too great to permit them to use the inner harbor anchorage...

  2. 33 CFR 110.250 - St. Thomas Harbor, Charlotte Amalie, V.I.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., V.I. (a) The anchorage grounds—(1) Inner harbor anchorage. Beginning at a point bearing 85°, 525... shall also be used by vessels having drafts too great to permit them to use the inner harbor anchorage...

  3. 33 CFR 110.250 - St. Thomas Harbor, Charlotte Amalie, V.I.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., V.I. (a) The anchorage grounds—(1) Inner harbor anchorage. Beginning at a point bearing 85°, 525... shall also be used by vessels having drafts too great to permit them to use the inner harbor anchorage...

  4. 33 CFR 110.250 - St. Thomas Harbor, Charlotte Amalie, V.I.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., V.I. (a) The anchorage grounds—(1) Inner harbor anchorage. Beginning at a point bearing 85°, 525... shall also be used by vessels having drafts too great to permit them to use the inner harbor anchorage...

  5. Underwater localization of pure tones by harbor seals (Phoca vitulina).

    PubMed

    Bodson, Anaïs; Miersch, Lars; Dehnhardt, Guido

    2007-10-01

    The underwater sound localization acuity of harbor seals (Phoca vitulina) was measured in the horizontal plane. Minimum audible angles (MAAs) of pure tones were determined as a function of frequency from 0.2 to 16 kHz for two seals. Testing was conducted in a 10-m-diam underwater half circle using a right/left psychophysical procedure. The results indicate that for both harbor seals, MAAs were large at high frequencies (13.5 degrees and 17.4 degrees at 16 kHz), transitional at intermediate frequencies (9.6 degrees and 10.1 degrees at 4 kHz), and particularly small at low frequencies (3.2 degrees and 3.1 degrees at 0.2 kHz). Harbor seals seem to be able to utilize both binaural cues, interaural time differences (ITDs) and interaural intensity differences (IIDs), but a significant decrease in the sound localization acuity with increasing frequency suggests that IID cues may not be as robust as ITD cues under water. These results suggest that the harbor seal can be regarded as a low-frequency specialist. Additionally, to obtain a MAA more representative of the species, the horizontal underwater MAA of six adult harbor seals was measured at 2 kHz under identical conditions. The MAAs of the six animals ranged from 8.8 degrees to 11.7 degrees , resulting in a mean MAA of 10.3 degrees .

  6. Genetics Home Reference: Floating-Harbor syndrome

    MedlinePlus

    ... Patton MA, Hurst J, Donnai D, McKeown CM, Cole T, Goodship J. Floating-Harbor syndrome. J Med ... medicine? What is newborn screening? New Pages Lyme disease Fibromyalgia White-Sutton syndrome All New & Updated Pages ...

  7. 33 CFR 117.661 - Duluth Ship Canal (Duluth-Superior Harbor).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Duluth Ship Canal (Duluth-Superior Harbor). 117.661 Section 117.661 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Minnesota § 117.661 Duluth Ship Canal (Duluth-Superior Harbor). The draw o...

  8. 33 CFR 117.753 - Ship Channel, Great Egg Harbor Bay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Ship Channel, Great Egg Harbor... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.753 Ship Channel, Great Egg Harbor Bay. The draw of the S52 (Ship Channel) bridge, mile 0.5 between Somers Point and Ocean...

  9. 33 CFR 117.753 - Ship Channel, Great Egg Harbor Bay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Ship Channel, Great Egg Harbor... SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New Jersey § 117.753 Ship Channel, Great Egg Harbor Bay. The draw of the S52 (Ship Channel) bridge, mile 0.5 between Somers Point and Ocean...

  10. 33 CFR 334.870 - San Diego Harbor, Calif.; restricted area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false San Diego Harbor, Calif... THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.870 San Diego Harbor... the Pacific Ocean in North San Diego Bay in an area extending from the western boundary of North...

  11. 33 CFR 334.870 - San Diego Harbor, Calif.; restricted area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false San Diego Harbor, Calif... THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.870 San Diego Harbor... the Pacific Ocean in North San Diego Bay in an area extending from the western boundary of North...

  12. 77 FR 19573 - Safety Zone; Wedding Fireworks Display, Boston Inner Harbor, Boston, MA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ...-AA00 Safety Zone; Wedding Fireworks Display, Boston Inner Harbor, Boston, MA AGENCY: Coast Guard, DHS... zone on the navigable waters of the Boston Inner Harbor in the vicinity of Anthony's Pier 4, Boston, MA... Boston Inner Harbor in the vicinity of Anthony's Pier 4, Boston, MA. The Captain of the Port (COTP...

  13. 33 CFR 110.231 - Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Passenger Vessel Anchorage. 110.231 Section 110.231 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.231 Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage. (a) The anchorage grounds. Ketchikan Harbor, Alaska, Large...

  14. 33 CFR 110.231 - Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Passenger Vessel Anchorage. 110.231 Section 110.231 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.231 Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage. (a) The anchorage grounds. Ketchikan Harbor, Alaska, Large...

  15. 33 CFR 110.231 - Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Passenger Vessel Anchorage. 110.231 Section 110.231 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.231 Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage. (a) The anchorage grounds. Ketchikan Harbor, Alaska, Large...

  16. 33 CFR 110.231 - Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Passenger Vessel Anchorage. 110.231 Section 110.231 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.231 Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage. (a) The anchorage grounds. Ketchikan Harbor, Alaska, Large...

  17. 33 CFR 110.231 - Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Passenger Vessel Anchorage. 110.231 Section 110.231 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.231 Ketchikan Harbor, Alaska, Large Passenger Vessel Anchorage. (a) The anchorage grounds. Ketchikan Harbor, Alaska, Large...

  18. APPLICATION OF EMAP METHODS AND INDICATORS TO THE NY/NJ HARBOR

    EPA Science Inventory

    The Comprehensive Conservation and Management Plan (CCMP) for the NY/NJ Harbor requires specific management actions to maintain and restore the Harbor environment. It also specifies that the progress of these management actions on the improvement of sediment quality and biologic...

  19. 33 CFR 117.753 - Ship Channel, Great Egg Harbor Bay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ship Channel, Great Egg Harbor Bay. 117.753 Section 117.753 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND..., Great Egg Harbor Bay. The draw of the S52 (Ship Channel) bridge, mile 0.5 between Somers Point and Ocean...

  20. 33 CFR 117.753 - Ship Channel, Great Egg Harbor Bay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Ship Channel, Great Egg Harbor Bay. 117.753 Section 117.753 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND..., Great Egg Harbor Bay. The draw of the S52 (Ship Channel) bridge, mile 0.5 between Somers Point and Ocean...