title: Repair of nitrous acid damage to DNA in Escherichia coli.
abstract: A number of mutant strains of Escherichia coli have been examined for their sensitivity to nitrous acid and in some instances to methylmethanesulfonate. All ung- mutants tested are abnormally sensitive to nitrous acid. Since the ung mutation is phenotypically expressed as a defect in uracil DNA glycosidase, this observation supports the contention that treatment of cells with nitrous acid causes deamination of cytosine to uracil. In addition the observed sentitivity indicates that the ung gene is involved in the repair of uracil in DNA. Studies with other mutants suggest that both exonuclease III and DNA polymerase I of E. coli are involved in the repair of nitrous acid damage in vivo.
mesh_terms: D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D004256:DNA Polymerase I / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D005838:Genotype; D007700:Kinetics; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008937:Mitomycins / Q000494:pharmacology; D009573:Nitrites / Q000494:pharmacology*; D009608:Nitrous Acid / Q000494:pharmacology*; D013045:Species Specificity; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial; D008937:Mitomycins; D009573:Nitrites; D008741:Methyl Methanesulfonate; D004256:DNA Polymerase I; D009608:Nitrous Acid