The mycobacterial LysR-type regulator OxyS responds to oxidative stress and negatively regulates expression of the catalase-peroxidase gene.

ABSTRACT: Protection against oxidative stress is one of the primary defense mechanisms contributing to the survival of Mycobacterium tuberculosis in the host. In this study, we provide evidence that OxyS, a LysR-type transcriptional regulator functions as an oxidative stress response regulator in mycobacteria. Overexpression of OxyS lowers expression of the catalase-peroxidase (KatG) gene in M. smegmatis. OxyS binds directly with the katG promoter region and a conserved, GC-rich T-N(11)-A motif for OxyS binding was successfully characterized in the core binding site. Interestingly, the DNA-binding activity of OxyS was inhibited by H(2)O(2), but not by dithiothreitol. Cys25, which is situated at the DNA-binding domain of OxyS, was found to have a regulatory role for the DNA-binding ability of OxyS in

SUBMITTER: Li Y 

PROVIDER: S-EPMC3260234 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature