Nitroreductase A is regulated as a member of the soxRS regulon of Escherichia coli.
Nitroreductase A catalyzes the divalent reduction of nitro compounds, quinones, and dyes by NADPH. In this paper, nitroreductase A is induced in Escherichia coli by exposure to paraquat in a manner that depends on the expression of soxR. Nitroreductase activity was only slightly induced by paraquat in a strain bearing a mutational defect in the gene encoding nitroreductase A, but it was approximately 3-fold induced in the parental strain. Nitroreductase A thus appears to be a member of the soxRS regulon and probably contributes to the defenses against oxidative stress by minimizing the redox cycling attendant upon the univalent reduction of nitro compounds, quinones, and dyes.
Liochev
S I
SI
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
Hausladen
A
A
Fridovich
I
I
D019008:Drug Resistance, Neoplasm; D004790:Enzyme Induction; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D016296:Mutagenesis; D009243:NAD / Q000378:metabolism; D009601:Nitroreductases / Q000096:biosynthesis / Q000235:genetics*; D010269:Paraquat / Q000494:pharmacology; D018085:Regulon
D029968:Escherichia coli Proteins; D009243:NAD; C116053:NfsA protein, E coli; D009601:Nitroreductases; D010269:Paraquat