Redefining the Clostridioides difficile σ ^B Regulon: σ ^B Activates Genes Involved in Detoxifying Radicals That Can Result from the Exposure to Antimicrobials and Hydrogen Peroxide

Abstract

Sigma B is the alternative sigma factor governing stress response in many Gram-positive bacteria. In C. difficile , a sigB mutant shows pleiotropic transcriptional effects. Here, we determine genes that are likely direct targets of σ B by evaluating the transcriptional effects of σ B overproduction, provide biochemical evidence of direct transcriptional activation by σ B , and show that σ B -dependent genes can be activated by antimicrobials. Together, our data suggest that σ B is a key player in dealing with toxic radicals.

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