title: [The role of thiol redox systems in the peroxide stress response of Escherichia coli].
abstract: The effect of mutations in the genes encoding glutathione, glutaredoxin, thioredoxin, and thioredoxin reductase on the response of growing Escherichia coli to oxidative stress was studied. The gshA mutants defective in glutathione synthesis had the lowest resistance to high doses of H2O2, whereas the trxB mutants defective in thioredoxin reductase synthesis had the highest resistance to this oxidant, exceeding that of the parent strain. Among the studied mutants, the trxB cells demonstrated the highest basic levels of catalase activity and intracellular glutathione; they were able to rapidly reach the normal GSH level after oxidative stress. At the same time, these bacteria showed high frequency of induced mutations. The expression of the katG and sulA genes suggests that, having different sensitivity to high oxidant concentrations, the studied mutants differ primarily in their ability to induce the antioxidant genes of the OxyR and SOS regulons.
authors.forename: O N
authors.initials: ON
authors.lastname: Oktiabr'skiĭ
authors.forename: N G
authors.initials: NG
authors.lastname: Muzyka
authors.forename: V Iu
authors.initials: VIu
authors.lastname: Ushakov
authors.forename: G V
authors.initials: GV
authors.lastname: Smirnova
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D054477:Glutaredoxins / Q000502:physiology; D005978:Glutathione / Q000502:physiology; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010545:Peroxides; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics; D013014:SOS Response, Genetics / Q000235:genetics; D013880:Thioredoxin-Disulfide Reductase / Q000502:physiology; D013879:Thioredoxins / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D054477:Glutaredoxins; D010545:Peroxides; D012097:Repressor Proteins; D014157:Transcription Factors; C499299:oxyR protein, E coli; D013879:Thioredoxins; D013880:Thioredoxin-Disulfide Reductase; D005978:Glutathione