OxyR and SoxRS Regulation of fur

• DOI: 10.1128/jb.181.15.4639-4643.1999
• Publication Date: 2019-12-31T16:37:07Z
• Authors: Ming Zheng; Bernard Doan; Thomas D. Schneider; Gisela Storz
• Keywords: Regulon; Hydroxyl radical

ABSTRACT The cytotoxic effects of reactive oxygen species are largely mediated by iron. Hydrogen peroxide reacts with iron to form the extremely and damaging hydroxyl radical via Fenton reaction. Superoxide anion accelerates this reaction because dismutation superoxide leads increased levels hydrogen elevates intracellular concentration attacking iron-sulfur proteins. We found that regulators Escherichia coli responses oxidative stress, OxyR SoxRS, activate expression Fur, global repressor ferric ion uptake. A transcript encoding Fur was induced in a wild-type strain but not Δ oxyR strain, DNase I footprinting assays showed binds fur promoter. In cells treated superoxide-generating compound paraquat, we observed induction longer encompassing both its immediate upstream gene fldA , which encodes flavodoxin. This polycistronic mRNA is paraquat soxRS SoxS shown bind These results demonstrate metabolism coordinately regulated stress defenses.