Title Regulation of fpr Gene encoding NADPH :Ferredoxin oxidoreductase by the soxRS locus in escherichia coli
Author Koh, Young Sang · Chouh, Jenny · Roe, Jung Hye *
Address Department of Microbiology, College of Natural Sciences; Research Center for Molecular Microbiology, Seoul National University
Bibliography Journal of Microbiology, 34(2),137-143, 1996,
Key Words Escherichia coli, fpr, NADPH : ferrodoxin oxidoreductase, oxidative stress, soxRS regulon
Abstract We isolated a promoter inducible by paraquat, a superoxide-generating agent, from Escherichia coli using a promoter-probing plasmid pRS415. From sequence analysis we found out the promoter is for fpr ENCODING nadph : ferredoxin oxidoreductase. We constructed on operon fusion of lacZ gene with fpr promoter to monitor the expression of the gene in the single-copy state. LacZ expression generators, menadione and plumbagin, also induced the expression of β-galactosidase in the fusion strain. On the other hand, no significant induction was observed by treatment with hydrogen peroxide, ethanol, and heat shock. Induction of β-galactosidase was significantly reduced by introducing a Δsox 8 :: cat of soxS3 :: Tn10 mutation into the fusion strain, indicating that fpr gene is a member of the soxRS regulon. The transcriptional start site was determined by primer extension analysis. Possible roles of fpr induction in superoxide stress were discussed.
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