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[PMID]:29295984
[Au] Autor:Goyal N; Rossi MJ; Mazina OM; Chi Y; Moritz RL; Clurman BE; Mazin AV
[Ad] Endereço:Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA.
[Ti] Título:RAD54 N-terminal domain is a DNA sensor that couples ATP hydrolysis with branch migration of Holliday junctions.
[So] Source:Nat Commun;9(1):34, 2018 01 02.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In eukaryotes, RAD54 catalyzes branch migration (BM) of Holliday junctions, a basic process during DNA repair, replication, and recombination. RAD54 also stimulates RAD51 recombinase and has other activities. Here, we investigate the structural determinants for different RAD54 activities. We find that the RAD54 N-terminal domain (NTD) is responsible for initiation of BM through two coupled, but distinct steps; specific binding to Holliday junctions and RAD54 oligomerization. Furthermore, we find that the RAD54 oligomeric state can be controlled by NTD phosphorylation at S49, a CDK2 consensus site, which inhibits RAD54 oligomerization and, consequently, BM. Importantly, the effect of phosphorylation on RAD54 oligomerization is specific for BM, as it does not affect stimulation of RAD51 recombinase by RAD54. Thus, the transition of the oligomeric states provides an important control of the biological functions of RAD54 and, likely, other multifunctional proteins.
[Mh] Termos MeSH primário: Adenosina Trifosfatases/metabolismo
DNA Helicases/metabolismo
DNA Cruciforme/metabolismo
Proteínas Nucleares/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Animais
Sítios de Ligação/genética
Linhagem Celular
DNA Helicases/química
DNA Helicases/genética
Reparo do DNA
DNA Cruciforme/química
DNA Cruciforme/genética
Seres Humanos
Hidrólise
Proteínas Nucleares/química
Proteínas Nucleares/genética
Conformação de Ácido Nucleico
Fosforilação
Multimerização Proteica
Recombinação Genética
Homologia de Sequência de Aminoácidos
Células Sf9
Spodoptera
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (DNA, Cruciform); 0 (Nuclear Proteins); 0 (RAD54L protein, human); EC 3.6.1.- (Adenosine Triphosphatases); EC 3.6.4.- (DNA Helicases)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180306
[Lr] Data última revisão:
180306
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180104
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02497-x


  2 / 478 MEDLINE  
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[PMID]:28911104
[Au] Autor:Nußbaumer F; Juen MA; Gasser C; Kremser J; Müller T; Tollinger M; Kreutz C
[Ad] Endereço:Institute of Organic Chemistry, Leopold-Franzens-University of Innsbruck, and Center for Molecular Biosciences Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
[Ti] Título:Synthesis and incorporation of 13C-labeled DNA building blocks to probe structural dynamics of DNA by NMR.
[So] Source:Nucleic Acids Res;45(15):9178-9192, 2017 Sep 06.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We report the synthesis of atom-specifically 13C-modified building blocks that can be incorporated into DNA via solid phase synthesis to facilitate investigations on structural and dynamic features via NMR spectroscopy. In detail, 6-13C-modified pyrimidine and 8-13C purine DNA phosphoramidites were synthesized and incorporated into a polypurine tract DNA/RNA hybrid duplex to showcase the facile resonance assignment using site-specific labeling. We also addressed micro- to millisecond dynamics in the mini-cTAR DNA. This DNA is involved in the HIV replication cycle and our data points toward an exchange process in the lower stem of the hairpin that is up-regulated in the presence of the HIV-1 nucleocapsid protein 7. As another example, we picked a G-quadruplex that was earlier shown to exist in two folds. Using site-specific 8-13C-2'deoxyguanosine labeling we were able to verify the slow exchange between the two forms on the chemical shift time scale. In a real-time NMR experiment the re-equilibration of the fold distribution after a T-jump could be monitored yielding a rate of 0.012 min-1. Finally, we used 13C-ZZ-exchange spectroscopy to characterize the kinetics between two stacked X-conformers of a Holliday junction mimic. At 25°C, the refolding process was found to occur at a forward rate constant of 3.1 s-1 and with a backward rate constant of 10.6 s-1.
[Mh] Termos MeSH primário: DNA Cruciforme/química
DNA/química
Repetição Terminal Longa de HIV
Proteínas do Nucleocapsídeo/química
Compostos Organofosforados/química
RNA/química
[Mh] Termos MeSH secundário: Pareamento de Bases
Isótopos de Carbono
Quadruplex G
HIV-1/química
Marcação por Isótopo
Espectroscopia de Ressonância Magnética
Modelos Moleculares
Mimetismo Molecular
Conformação de Ácido Nucleico
Compostos Organofosforados/síntese química
Técnicas de Síntese em Fase Sólida
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carbon Isotopes); 0 (DNA, Cruciform); 0 (Nucleocapsid Proteins); 0 (Organophosphorus Compounds); 0 (phosphoramidite); 63231-63-0 (RNA); 9007-49-2 (DNA)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170916
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx592


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[PMID]:28834211
[Au] Autor:Ohshita K; Fukui K; Sato M; Morisawa T; Hakumai Y; Morono Y; Inagaki F; Yano T; Ashiuchi M; Wakamatsu T
[Ad] Endereço:Agricultural Science, Graduate School of Integrated Arts and Sciences, Kochi University, Nankoku, Japan.
[Ti] Título:Archaeal MutS5 tightly binds to Holliday junction similarly to eukaryotic MutSγ.
[So] Source:FEBS J;284(20):3470-3483, 2017 Oct.
[Is] ISSN:1742-4658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Archaeal DNA recombination mechanism and the related proteins are similar to those in eukaryotes. However, no functional homolog of eukaryotic MutSγ, which recognizes Holliday junction to promote homologous recombination, has been identified in archaea. Hence, the whole molecular mechanism of archaeal homologous recombination has not yet been revealed. In this study, to identify the archaeal functional homolog of MutSγ, we focused on a functionally uncharacterized MutS homolog, MutS5, from a hyperthermophilic archaeon Pyrococcus horikoshii (phMutS5). Archaeal MutS5 has a Walker ATPase motif-containing amino acid sequence that shows similarity to the ATPase domain of MutSγ. It is known that the ATPase domain of MutS homologs is also a dimerization domain. Chemical cross-linking revealed that purified phMutS5 has an ability to dimerize in solution. phMutS5 bound to Holliday junction with a higher affinity than to other branched and linear DNAs, which resembles the DNA-binding specificities of MutSγ and bacterial MutS2, a Holliday junction-resolving MutS homolog. However, phMutS5 has no nuclease activity against branched DNA unlike MutS2. The ATPase activity of phMutS5 was significantly stimulated by the presence of Holliday junction similarly to MutSγ. Furthermore, site-directed mutagenesis revealed that the ATPase activity is dependent on the Walker ATPase motif of the protein. These results suggest that archaeal MutS5 should stabilize the Holliday junction and play a role in homologous recombination, which is analogous to the function of eukaryotic MutSγ.
[Mh] Termos MeSH primário: Proteínas Arqueais/metabolismo
DNA Cruciforme/metabolismo
Eucariotos/metabolismo
Pyrococcus furiosus/metabolismo
[Mh] Termos MeSH secundário: Adenosina Trifosfatases/metabolismo
Sequência de Aminoácidos
Proteínas Arqueais/química
Proteínas Arqueais/genética
Sequência de Bases
Clonagem Molecular
Mutagênese Sítio-Dirigida
Mutação/genética
Ligação Proteica
Conformação Proteica
Pyrococcus furiosus/crescimento & desenvolvimento
Recombinação Genética
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Archaeal Proteins); 0 (DNA, Cruciform); EC 3.6.1.- (Adenosine Triphosphatases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170824
[St] Status:MEDLINE
[do] DOI:10.1111/febs.14204


  4 / 478 MEDLINE  
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[PMID]:28654322
[Au] Autor:Fresco JR; Amosova O
[Ad] Endereço:Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544; email: jrfresco@princeton.edu , amosova@princeton.edu.
[Ti] Título:Site-Specific Self-Catalyzed DNA Depurination: A Biological Mechanism That Leads to Mutations and Creates Sequence Diversity.
[So] Source:Annu Rev Biochem;86:461-484, 2017 Jun 20.
[Is] ISSN:1545-4509
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Self-catalyzed DNA depurination is a sequence-specific physiological mechanism mediated by spontaneous extrusion of a stem-loop catalytic intermediate. Hydrolysis of the 5'G residue of the 5'GA/TGG loop and of the first 5'A residue of the 5'GAGA loop, together with particular first stem base pairs, specifies their hydrolysis without involving protein, cofactor, or cation. As such, this mechanism is the only known DNA catalytic activity exploited by nature. The consensus sequences for self-depurination of such G- and A-loop residues occur in all genomes examined across the phyla, averaging one site every 2,000-4,000 base pairs. Because apurinic sites are subject to error-prone repair, leading to substitution and short frameshift mutations, they are both a source of genome damage and a means for creating sequence diversity. Their marked overrepresentation in genomes, and largely unchanging density from the lowest to the highest organisms, indicate their selection over the course of evolution. The mutagenicity at such sites in many human genes is associated with loss of function of key proteins responsible for diverse diseases.
[Mh] Termos MeSH primário: Adenina/metabolismo
Síndrome de Bloom/genética
DNA Catalítico/genética
Guanina/metabolismo
Polimorfismo Genético
Síndrome de Werner/genética
[Mh] Termos MeSH secundário: Evolução Biológica
Síndrome de Bloom/metabolismo
Síndrome de Bloom/patologia
Catálise
Reparo do DNA
DNA Catalítico/metabolismo
DNA Cruciforme/genética
DNA Cruciforme/metabolismo
DNA de Cadeia Simples/genética
DNA de Cadeia Simples/metabolismo
Seres Humanos
Hidrólise
Sequências Repetidas Invertidas
Mutação
Síndrome de Werner/metabolismo
Síndrome de Werner/patologia
Globinas beta/genética
Globinas beta/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (DNA, Catalytic); 0 (DNA, Cruciform); 0 (DNA, Single-Stranded); 0 (beta-Globins); 5Z93L87A1R (Guanine); JAC85A2161 (Adenine)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170704
[Lr] Data última revisão:
170704
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170628
[St] Status:MEDLINE
[do] DOI:10.1146/annurev-biochem-070611-095951


  5 / 478 MEDLINE  
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[PMID]:28642366
[Au] Autor:Kshirsagar R; Ghodke I; Muniyappa K
[Ad] Endereço:From the Department of Biochemistry, Indian Institute of Science, Bangalore 560012, India.
[Ti] Título: Red1 protein exhibits nonhomologous DNA end-joining activity and potentiates Hop1-promoted pairing of double-stranded DNA.
[So] Source:J Biol Chem;292(33):13853-13866, 2017 Aug 18.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Elucidation of the function of synaptonemal complex (SC) in has mainly focused on analysis of recombination-defective meiotic mutants. Consequently, significant gaps remain in the mechanistic understanding of the activities of various SC proteins and the functional relationships among them. Hop1 and Red1 are essential structural components of the SC axial/lateral elements. Previous studies have demonstrated that Hop1 is a structure-selective DNA-binding protein exhibiting high affinity for the Holliday junction and promoting DNA bridging, condensation, and pairing between double-stranded DNA molecules. However, the exact mode of action of Red1 remains unclear, although it is known to interact with Hop1 and to suppress the spore viability defects of mutant alleles. Here, we report the purification and functional characterization of the full-length Red1 protein. Our results revealed that Red1 forms a stable complex with Hop1 and provided quantitative insights into their physical interactions. Mechanistically, Red1 preferentially associated with the Holliday junction and 3-way junction rather than with single- or double-stranded DNA with overhangs. Although Hop1 and Red1 exhibited similar binding affinities toward several DNA substrates, the two proteins displayed some significant differences. Notably, Red1, by itself, lacked DNA-pairing ability; however, it potentiated Hop1-promoted intermolecular pairing between double-stranded DNA molecules. Moreover, Red1 exhibited nonhomologous DNA end-joining activity, thus revealing an unexpected role for Red1 in recombination-based DNA repair. Collectively, this study presents the first direct insights into Red1's mode of action and into the mechanism underlying its role in chromosome synapsis and recombination.
[Mh] Termos MeSH primário: Reparo do DNA por Junção de Extremidades
DNA Fúngico/metabolismo
Proteínas de Ligação a DNA/agonistas
Proteínas de Saccharomyces cerevisiae/agonistas
Proteínas de Saccharomyces cerevisiae/metabolismo
Saccharomyces cerevisiae/fisiologia
Complexo Sinaptonêmico/metabolismo
[Mh] Termos MeSH secundário: Pareamento de Bases
Pareamento Cromossômico
DNA Circular/química
DNA Circular/metabolismo
DNA Cruciforme/química
DNA Cruciforme/metabolismo
DNA Fúngico/química
Proteínas de Ligação a DNA/química
Proteínas de Ligação a DNA/genética
Proteínas de Ligação a DNA/metabolismo
Cinética
Microscopia de Força Atômica
Mutação
Multimerização Proteica
Estabilidade Proteica
Proteínas Recombinantes/química
Proteínas Recombinantes/metabolismo
Reparo de DNA por Recombinação
Proteínas de Saccharomyces cerevisiae/química
Proteínas de Saccharomyces cerevisiae/genética
Especificidade por Substrato
Ressonância de Plasmônio de Superfície
Complexo Sinaptonêmico/química
Complexo Sinaptonêmico/genética
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Circular); 0 (DNA, Cruciform); 0 (DNA, Fungal); 0 (DNA-Binding Proteins); 0 (HOP1 protein, S cerevisiae); 0 (RED1 protein, S cerevisiae); 0 (Recombinant Proteins); 0 (Saccharomyces cerevisiae Proteins)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170624
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.796425


  6 / 478 MEDLINE  
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[PMID]:28542519
[Au] Autor:Wu Z; Gu C; Tembrock LR; Zhang D; Ge S
[Ad] Endereço:State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
[Ti] Título:Characterization of the whole chloroplast genome of Chikusichloa mutica and its comparison with other rice tribe (Oryzeae) species.
[So] Source:PLoS One;12(5):e0177553, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Chloroplast genomes are a significant genomic resource in plant species and have been used in many research areas. The complete genomic information from wild crop species could supply a valuable genetic reservoir for breeding. Chikusichloa mutica is one of the most important wild distant relatives of cultivated rice. In this study, we sequenced and characterized its complete chloroplast (cp) genome and compared it with other species in the same tribe. The whole cp genome sequence is 136,603 bp in size and exhibits a typical quadripartite structure with large and small single-copy regions (LSC, 82,327 bp; SSC, 12,598 bp) separated by a pair of 20,839-bp inverted repeats (IRA, B). A total of 110 unique genes are annotated, including 76 protein-coding genes, 4 ribosomal RNA genes and 30 tRNA genes. The genome structure, gene order, GC content, and other features are similar to those of other angiosperm cp genomes. When comparing the cp genomes between Oryzinae and Zizaniinae subtribes, the main differences were found between the junction regions and distribution of simple sequence repeats (SSRs). In comparing the two Chikusichloa species, the genomes were only 40 bp different in length and 108 polymorphic sites, including 83 single nucleotide substitutions (SNPs) and 25 insertion-deletions (Indels), were found between the whole cp genomes. The complete cp genome of C. mutica will be an important genetic tool for future breeding programs and understanding the evolution of wild rice relatives.
[Mh] Termos MeSH primário: Genoma de Cloroplastos
Oryza/classificação
Oryza/genética
Poaceae/classificação
Poaceae/genética
[Mh] Termos MeSH secundário: Sequência Conservada
Produtos Agrícolas/classificação
Produtos Agrícolas/genética
DNA de Cloroplastos/química
DNA de Cloroplastos/genética
DNA Cruciforme/química
DNA Cruciforme/genética
Evolução Molecular
Variação Genética
Mutação INDEL
Repetições de Microssatélites
Conformação de Ácido Nucleico
Filogenia
Polimorfismo de Nucleotídeo Único
Especificidade da Espécie
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Chloroplast); 0 (DNA, Cruciform)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170911
[Lr] Data última revisão:
170911
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170526
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0177553


  7 / 478 MEDLINE  
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[PMID]:28511132
[Au] Autor:Gándara C; de Lucena DKC; Torres R; Serrano E; Altenburger S; Graumann PL; Alonso JC
[Ad] Endereço:Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CNB-CSIC, Madrid, Spain.
[Ti] Título:Activity and in vivo dynamics of Bacillus subtilis DisA are affected by RadA/Sms and by Holliday junction-processing proteins.
[So] Source:DNA Repair (Amst);55:17-30, 2017 Jul.
[Is] ISSN:1568-7856
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Bacillus subtilis c-di-AMP synthase DisA and RecA-related RadA/Sms are involved in the repair of DNA damage in exponentially growing cells. We provide genetic evidence that DisA or RadA/Sms is epistatic to the branch migration translocase (BMT) RecG and the Holliday junction (HJ) resolvase RecU in response to DNA damage. We provide genetic evidence damage. Functional DisA-YFP formed dynamic foci in exponentially growing cells, which moved through the nucleoids at a speed compatible with a DNA-scanning mode. DisA formed more static structures in the absence of RecU or RecG than in wild type cells, while dynamic foci were still observed in cells lacking the BMT RuvAB. Purified DisA synthesizes c-di-AMP, but interaction with RadA/Sms or with HJ DNA decreases DisA-mediated c-di-AMP synthesis. RadA/Sms-YFP also formed dynamic foci in growing cells, but the foci moved throughout the cells rather than just on the nucleoids, and co-localized rarely with DisA-YFP foci, suggesting that RadA/Sms and DisA interact only transiently in unperturbed conditions. Our data suggest a model in which DisA moving along dsDNA indicates absence of DNA damage/replication stress via normal c-di-AMP levels, while interaction with HJ DNA/halted forks leads to reduced c-di-AMP levels and an ensuing block in cell proliferation. RadA/Sms may be involved in modulating DisA activities.
[Mh] Termos MeSH primário: Bacillus subtilis/enzimologia
Proteínas de Bactérias/metabolismo
DNA Cruciforme/metabolismo
Proteínas de Ligação a DNA/metabolismo
Nucleotidiltransferases/metabolismo
Reparo de DNA por Recombinação
[Mh] Termos MeSH secundário: Bacillus subtilis/genética
Dano ao DNA
Replicação do DNA
DNA Bacteriano/metabolismo
Fosfatos de Dinucleosídeos/biossíntese
Resolvases de Junção Holliday
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (DNA, Bacterial); 0 (DNA, Cruciform); 0 (DNA-Binding Proteins); 0 (Dinucleoside Phosphates); 0 (RadA protein, bacteria); 0 (cyclic diadenosine phosphate); EC 2.7.7.- (Nucleotidyltransferases); EC 3.1.21.- (Holliday Junction Resolvases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170810
[Lr] Data última revisão:
170810
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170517
[St] Status:MEDLINE


  8 / 478 MEDLINE  
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[PMID]:28505149
[Au] Autor:Claeys Bouuaert C; Keeney S
[Ad] Endereço:Molecular Biology Program, Memorial Sloan Kettering Cancer Center and Howard Hughes Medical Institute, New York, New York, United States of America.
[Ti] Título:Distinct DNA-binding surfaces in the ATPase and linker domains of MutLγ determine its substrate specificities and exert separable functions in meiotic recombination and mismatch repair.
[So] Source:PLoS Genet;13(5):e1006722, 2017 May.
[Is] ISSN:1553-7404
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Mlh1-Mlh3 (MutLγ) is a mismatch repair factor with a central role in formation of meiotic crossovers, presumably through resolution of double Holliday junctions. MutLγ has DNA-binding, nuclease, and ATPase activities, but how these relate to one another and to in vivo functions are unclear. Here, we combine biochemical and genetic analyses to characterize Saccharomyces cerevisiae MutLγ. Limited proteolysis and atomic force microscopy showed that purified recombinant MutLγ undergoes ATP-driven conformational changes. In vitro, MutLγ displayed separable DNA-binding activities toward Holliday junctions (HJ) and, surprisingly, single-stranded DNA (ssDNA), which was not predicted from current models. MutLγ bound DNA cooperatively, could bind multiple substrates simultaneously, and formed higher-order complexes. FeBABE hydroxyl radical footprinting indicated that the DNA-binding interfaces of MutLγ for ssDNA and HJ substrates only partially overlap. Most contacts with HJ substrates were located in the linker regions of MutLγ, whereas ssDNA contacts mapped within linker regions as well as the N-terminal ATPase domains. Using yeast genetic assays for mismatch repair and meiotic recombination, we found that mutations within different DNA-binding surfaces exert separable effects in vivo. For example, mutations within the Mlh1 linker conferred little or no meiotic phenotype but led to mismatch repair deficiency. Interestingly, mutations in the N-terminal domain of Mlh1 caused a stronger meiotic defect than mlh1Δ, suggesting that the mutant proteins retain an activity that interferes with alternative recombination pathways. Furthermore, mlh3Δ caused more chromosome missegregation than mlh1Δ, whereas mlh1Δ but not mlh3Δ partially alleviated meiotic defects of msh5Δ mutants. These findings illustrate functional differences between Mlh1 and Mlh3 during meiosis and suggest that their absence impinges on chromosome segregation not only via reduced formation of crossovers. Taken together, our results offer insights into the structure-function relationships of the MutLγ complex and reveal unanticipated genetic relationships between components of the meiotic recombination machinery.
[Mh] Termos MeSH primário: Trifosfato de Adenosina/metabolismo
Troca Genética
Reparo de Erro de Pareamento de DNA
Proteína 1 Homóloga a MutL/metabolismo
Proteínas MutL/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Animais
Segregação de Cromossomos
DNA Cruciforme
DNA de Cadeia Simples/metabolismo
Meiose
Proteína 1 Homóloga a MutL/química
Proteína 1 Homóloga a MutL/genética
Proteínas MutL/química
Proteínas MutL/genética
Ligação Proteica
Domínios Proteicos
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/química
Proteínas de Saccharomyces cerevisiae/genética
Células Sf9
Spodoptera
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Cruciform); 0 (DNA, Single-Stranded); 0 (MLH1 protein, S cerevisiae); 0 (MLH3 protein, S cerevisiae); 0 (Saccharomyces cerevisiae Proteins); 8L70Q75FXE (Adenosine Triphosphate); EC 3.6.1.3 (MutL Protein Homolog 1); EC 3.6.1.3 (MutL Proteins)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170615
[Lr] Data última revisão:
170615
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170516
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pgen.1006722


  9 / 478 MEDLINE  
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[PMID]:28369583
[Au] Autor:Bellendir SP; Rognstad DJ; Morris LP; Zapotoczny G; Walton WG; Redinbo MR; Ramsden DA; Sekelsky J; Erie DA
[Ad] Endereço:Curriculum in Genetics and Molecular Biology, Chapel Hill, NC 27599, USA.
[Ti] Título:Substrate preference of Gen endonucleases highlights the importance of branched structures as DNA damage repair intermediates.
[So] Source:Nucleic Acids Res;45(9):5333-5348, 2017 May 19.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Human GEN1 and yeast Yen1 are endonucleases with the ability to cleave Holliday junctions (HJs), which are proposed intermediates in recombination. In vivo, GEN1 and Yen1 function secondarily to Mus81, which has weak activity on intact HJs. We show that the genetic relationship is reversed in Drosophila, with Gen mutants having more severe defects than mus81 mutants. In vitro, DmGen, like HsGEN1, efficiently cleaves HJs, 5΄ flaps, splayed arms, and replication fork structures. We find that the cleavage rates for 5΄ flaps are significantly higher than those for HJs for both DmGen and HsGEN1, even in vast excess of enzyme over substrate. Kinetic studies suggest that the difference in cleavage rates results from a slow, rate-limiting conformational change prior to HJ cleavage: formation of a productive dimer on the HJ. Despite the stark difference in vivo that Drosophila uses Gen over Mus81 and humans use MUS81 over GEN1, we find the in vitro activities of DmGen and HsGEN1 to be strikingly similar. These findings suggest that simpler branched structures may be more important substrates for Gen orthologs in vivo, and highlight the utility of using the Drosophila model system to further understand these enzymes.
[Mh] Termos MeSH primário: Dano ao DNA
Reparo do DNA
DNA Cruciforme/metabolismo
Proteínas de Drosophila/metabolismo
Drosophila melanogaster/enzimologia
Endonucleases/metabolismo
Resolvases de Junção Holliday/metabolismo
[Mh] Termos MeSH secundário: Animais
Sequência de Bases
Citoplasma/metabolismo
Replicação do DNA
Proteínas de Ligação a DNA/metabolismo
Embrião não Mamífero/metabolismo
Seres Humanos
Modelos Biológicos
Mutação/genética
Multimerização Proteica
Transporte Proteico
Proteínas de Schizosaccharomyces pombe/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Cruciform); 0 (DNA-Binding Proteins); 0 (Drosophila Proteins); 0 (MUS81 protein, S pombe); 0 (Schizosaccharomyces pombe Proteins); EC 3.1.- (Endonucleases); EC 3.1.- (GEN protein, Drosophila); EC 3.1.21.- (GEN1 protein, human); EC 3.1.21.- (Holliday Junction Resolvases)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171109
[Lr] Data última revisão:
171109
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx214


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[PMID]:28242723
[Au] Autor:Ringwald K; Yoneji S; Gardner J
[Ad] Endereço:Department of Microbiology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA kringwa2@illinois.edu.
[Ti] Título:Resolution of Mismatched Overlap Holliday Junction Intermediates by the Tyrosine Recombinase IntDOT.
[So] Source:J Bacteriol;199(10), 2017 May 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:CTnDOT is an integrated conjugative element found in species. CTnDOT contains and transfers antibiotic resistance genes. The element integrates into and excises from the host chromosome via a Holliday junction (HJ) intermediate as part of a site-specific recombination mechanism. The CTnDOT integrase, IntDOT, is a tyrosine recombinase with core-binding, catalytic, and amino-terminal (N) domains. Unlike well-studied tyrosine recombinases, such as lambda integrase (Int), IntDOT is able to resolve Holliday junctions containing heterology (mismatched bases) between the sites of strand exchange. All known natural isolates of CTnDOT contain mismatches in the overlap region between the sites of strand exchange. Previous work showed that IntDOT was unable to resolve synthetic Holliday junctions containing mismatched bases to products in the absence of the arm-type sites and a DNA-bending protein. We constructed synthetic HJs with the arm-type sites and tested them with the host factor (BHFa). We found that the addition of BHFa stimulated resolution of HJ intermediates with mismatched overlap regions to products. In addition, the L1 site is required for directionality of the reaction, particularly when the HJ contains mismatches. BHFa is required for product formation when the overlap region contains mismatches, and it stimulates resolution to products when the overlap region is identical. Without this DNA bending, the N domain of IntDOT is likely unable to bind the L1 arm-type site. These findings suggest that BHFa bends DNA into the necessary conformation for the higher-order complexes, including the L1 site, that are required for product formation. CTnDOT is a mobile element that carries antibiotic resistance genes and moves by site-selective recombination and subsequent conjugation. The recombination reaction is catalyzed by an integrase IntDOT that is a member of the tyrosine recombinase family. The reaction proceeds through ordered strand exchanges that generate a Holliday junction (HJ) intermediate. Unlike other tyrosine recombinases, IntDOT can resolve HJs containing mismatched bases in the overlap region , as is the case under natural conditions. However, HJ intermediates including only IntDOT core-type sites cannot be resolved to products if the HJ intermediate contains mismatched bases. We added arm-type sites in and in to the HJ intermediates and the protein BHFa to study the requirements for higher-order nucleoprotein complexes.
[Mh] Termos MeSH primário: Bacteroides/enzimologia
Bacteroides/metabolismo
Pareamento Incorreto de Bases
DNA Cruciforme/metabolismo
Recombinases/metabolismo
[Mh] Termos MeSH secundário: Bacteroides/genética
DNA/genética
DNA/metabolismo
Fatores Hospedeiros de Integração/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Cruciform); 0 (Integration Host Factors); 0 (Recombinases); 9007-49-2 (DNA)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:171025
[Lr] Data última revisão:
171025
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170301
[St] Status:MEDLINE



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