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Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair
Accurate repair of DNA double-strand breaks (DSBs) is crucial for cell survival and genome integrity. In Escherichia coli, DSBs are repaired by homologous recombination (HR), using an undamaged sister chromosome as template. The DNA intermediates of this pathway are expected to be branched molecules...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Public Library of Science
2021
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8386832/ https://www.ncbi.nlm.nih.gov/pubmed/34432790 http://dx.doi.org/10.1371/journal.pgen.1009717 |
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author | Yasmin, Tahirah Azeroglu, Benura Cockram, Charlotte A. Leach, David R. F. |
author_facet | Yasmin, Tahirah Azeroglu, Benura Cockram, Charlotte A. Leach, David R. F. |
author_sort | Yasmin, Tahirah |
collection | PubMed |
description | Accurate repair of DNA double-strand breaks (DSBs) is crucial for cell survival and genome integrity. In Escherichia coli, DSBs are repaired by homologous recombination (HR), using an undamaged sister chromosome as template. The DNA intermediates of this pathway are expected to be branched molecules that may include 4-way structures termed Holliday junctions (HJs), and 3-way structures such as D-loops and repair forks. Using a tool creating a site-specific, repairable DSB on only one of a pair of replicating sister chromosomes, we have determined how these branched DNA intermediates are distributed across a DNA region that is undergoing DSB repair. In cells, where branch migration and cleavage of HJs are limited by inactivation of the RuvABC complex, HJs and repair forks are principally accumulated within a distance of 12 kb from sites of recombination initiation, known as Chi, on each side of the engineered DSB. These branched DNA structures can even be detected in the region of DNA between the Chi sites flanking the DSB, a DNA segment not expected to be engaged in recombination initiation, and potentially degraded by RecBCD nuclease action. This is observed even in the absence of the branch migration and helicase activities of RuvAB, RadA, RecG, RecQ and PriA. The detection of full-length DNA fragments containing HJs in this central region implies that DSB repair can restore the two intact chromosomes, into which HJs can relocate prior to their resolution. The distribution of recombination intermediates across the 12kb region beyond Chi is altered in xonA, recJ and recQ mutants suggesting that, in the RecBCD pathway of DSB repair, exonuclease I stimulates the formation of repair forks and that RecJQ promotes strand-invasion at a distance from the recombination initiation sites. |
format | Online Article Text |
id | pubmed-8386832 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-83868322021-08-26 Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair Yasmin, Tahirah Azeroglu, Benura Cockram, Charlotte A. Leach, David R. F. PLoS Genet Research Article Accurate repair of DNA double-strand breaks (DSBs) is crucial for cell survival and genome integrity. In Escherichia coli, DSBs are repaired by homologous recombination (HR), using an undamaged sister chromosome as template. The DNA intermediates of this pathway are expected to be branched molecules that may include 4-way structures termed Holliday junctions (HJs), and 3-way structures such as D-loops and repair forks. Using a tool creating a site-specific, repairable DSB on only one of a pair of replicating sister chromosomes, we have determined how these branched DNA intermediates are distributed across a DNA region that is undergoing DSB repair. In cells, where branch migration and cleavage of HJs are limited by inactivation of the RuvABC complex, HJs and repair forks are principally accumulated within a distance of 12 kb from sites of recombination initiation, known as Chi, on each side of the engineered DSB. These branched DNA structures can even be detected in the region of DNA between the Chi sites flanking the DSB, a DNA segment not expected to be engaged in recombination initiation, and potentially degraded by RecBCD nuclease action. This is observed even in the absence of the branch migration and helicase activities of RuvAB, RadA, RecG, RecQ and PriA. The detection of full-length DNA fragments containing HJs in this central region implies that DSB repair can restore the two intact chromosomes, into which HJs can relocate prior to their resolution. The distribution of recombination intermediates across the 12kb region beyond Chi is altered in xonA, recJ and recQ mutants suggesting that, in the RecBCD pathway of DSB repair, exonuclease I stimulates the formation of repair forks and that RecJQ promotes strand-invasion at a distance from the recombination initiation sites. Public Library of Science 2021-08-25 /pmc/articles/PMC8386832/ /pubmed/34432790 http://dx.doi.org/10.1371/journal.pgen.1009717 Text en © 2021 Yasmin et al https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Yasmin, Tahirah Azeroglu, Benura Cockram, Charlotte A. Leach, David R. F. Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title | Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title_full | Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title_fullStr | Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title_full_unstemmed | Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title_short | Distribution of Holliday junctions and repair forks during Escherichia coli DNA double-strand break repair |
title_sort | distribution of holliday junctions and repair forks during escherichia coli dna double-strand break repair |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8386832/ https://www.ncbi.nlm.nih.gov/pubmed/34432790 http://dx.doi.org/10.1371/journal.pgen.1009717 |
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