Liochev S I, Hausladen A, Fridovich I
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.
Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3537-9. doi: 10.1073/pnas.96.7.3537.
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.