Regulation of hydroperoxidase (catalase) expression in Escherichia coli

As part of its adaptive response to oxidative stress, Escherichia coli produces two inducible hydroperoxidases called HPI and HPII. Upon exposure to sublethal levels of hydrogen peroxide, HPI expression is induced at the transcriptional level by OxyR, a member of the LysR family of autoregulators. OxyR, functioning as both a sensor and transducer, contains a critical redox-sensitive Cys residue that is oxidized by hydrogen peroxide. This is …