title: Repair of hydrogen peroxide-induced single-strand breaks in Escherichia coli deoxyribonucleic acid.
abstract: Near-ultraviolet (300 to 400 nm) irradiation of L-tryptophan yielded H2O2 (a toxic photoproduct) that was selectively lethal for rec and polA1 Escherichia coli mutants. H2O2 treatment of cells resulted in the induction of single-strand deoxyribonucleic acid breaks. These breaks were repaired to only a small extent in polA1, recA recB, and recA mutants, but were efficiently repaired in wild-type strains. We conclude that H2O2 deoxyribonucleic acid lesions require both the polA+ and recA+ pathways for repair.
mesh_terms: D002374:Catalase / Q000378:metabolism; D004256:DNA Polymerase I / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D005796:Genes; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D009154:Mutation; D011995:Recombination, Genetic
chemical_list: D004269:DNA, Bacterial; D006861:Hydrogen Peroxide; D002374:Catalase; D004256:DNA Polymerase I