Effects of the ssb-1 and ssb-113 mutations on survival and DNA repair in UV-irradiated delta uvrB strains of Escherichia coli K-12.
The molecular defect in DNA repair caused by ssb mutations (single-strand binding protein) was studied by analyzing DNA synthesis and DNA double-strand break production in UV-irradiated Escherichia coli delta uvrB strains. The presence of the ssb-113 mutation produced a large inhibition of DNA synthesis and led to the formation of double-strand breaks, whereas the ssb-1 mutation produced much less inhibition of DNA synthesis and fewer double-strand breaks. We suggest that the single-strand binding protein plays an important role in the replication of damaged DNA, and that it functions by protecting single-stranded parental DNa opposite daughter-strand gaps from nuclease attack.
D002470:Cell Survival / Q000528:radiation effects; D004260:DNA Repair; D004261:DNA Replication / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D005838:Genotype; D007700:Kinetics; D009154:Mutation; D013045:Species Specificity; D014466:Ultraviolet Rays