title: Increased superoxide radical production evokes inducible DNA repair in Escherichia coli.
abstract: Paraquat induced the SOS response in Escherichia coli. This was measured in terms of acquired resistance towards UV lethality in a wild-type strain and in terms of appearance of beta-galactosidase activity in a din::Mu d(Ap lac) fusion strain. However measured, the induction of the SOS response by paraquat was entirely dioxygen-dependent; whereas induction of the SOS response by mitomycin C was independent of the presence of dioxygen. As expected, recA(Def) and lexA(Ind-) isogenic strains did not show the SOS response. It appears likely that O-2, whose intracellular production is increased by paraquat, leads to DNA damage which in turn induces the SOS response.
authors.forename: M K
authors.initials: MK
authors.lastname: Brawn
authors.forename: I
authors.initials: I
authors.lastname: Fridovich
mesh_terms: D004260:DNA Repair / Q000187:drug effects; D004790:Enzyme Induction; D004926:Escherichia coli / Q000235:genetics*; D010100:Oxygen / Q000378:metabolism; D010269:Paraquat / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D014466:Ultraviolet Rays; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D013481:Superoxides; D001616:beta-Galactosidase; D010269:Paraquat; D010100:Oxygen