In:
PLOS Genetics, Public Library of Science (PLoS), Vol. 18, No. 12 ( 2022-12-27), p. e1010564-
Abstract:
DNA replication is essential for all living organisms. Several events can disrupt replication, including DNA damage (e.g., pyrimidine dimers, crosslinking) and so-called “roadblocks” (e.g., DNA-binding proteins or transcription). Bacteria have several well-characterized mechanisms for repairing damaged DNA and then restoring functional replication forks. However, little is known about the repair of stalled or arrested replication forks in the absence of chemical alterations to DNA. Using a library of random transposon insertions in Bacillus subtilis , we identified 35 genes that affect the ability of cells to survive exposure to an inhibitor that arrests replication elongation, but does not cause chemical alteration of the DNA. Genes identified include those involved in iron-sulfur homeostasis, cell envelope biogenesis, and DNA repair and recombination. In B . subtilis , and many bacteria, two nucleases (AddAB and RecJ) are involved in early steps in repairing replication forks arrested by chemical damage to DNA and loss of either nuclease causes increased sensitivity to DNA damaging agents. These nucleases resect DNA ends, leading to assembly of the recombinase RecA onto the single-stranded DNA. Notably, we found that disruption of recJ increased survival of cells following replication arrest, indicating that in the absence of chemical damage to DNA, RecJ is detrimental to survival. In contrast, and as expected, disruption of addA decreased survival of cells following replication arrest, indicating that AddA promotes survival. The different phenotypes of addA and recJ mutants appeared to be due to differences in assembly of RecA onto DNA. RecJ appeared to promote too much assembly of RecA filaments. Our results indicate that in the absence of chemical damage to DNA, RecA is dispensable for cells to survive replication arrest and that the stable RecA nucleofilaments favored by the RecJ pathway may lead to cell death by preventing proper processing of the arrested replication fork.
Type of Medium:
Online Resource
ISSN:
1553-7404
DOI:
10.1371/journal.pgen.1010564
DOI:
10.1371/journal.pgen.1010564.g001
DOI:
10.1371/journal.pgen.1010564.g002
DOI:
10.1371/journal.pgen.1010564.g003
DOI:
10.1371/journal.pgen.1010564.g004
DOI:
10.1371/journal.pgen.1010564.g005
DOI:
10.1371/journal.pgen.1010564.g006
DOI:
10.1371/journal.pgen.1010564.t001
DOI:
10.1371/journal.pgen.1010564.t002
DOI:
10.1371/journal.pgen.1010564.t003
DOI:
10.1371/journal.pgen.1010564.s001
DOI:
10.1371/journal.pgen.1010564.s002
Language:
English
Publisher:
Public Library of Science (PLoS)
Publication Date:
2022
detail.hit.zdb_id:
2186725-2
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