Genotoxic, Metabolic, and Oxidative Stresses Regulate the RNA Repair Operon of Salmonella enterica Serovar Typhimurium

Abstract

Homologs of the metazoan RNA repair enzymes RtcB and RtcA occur widely in eubacteria, suggesting a selective advantage. Although the enzymatic activities of the eubacterial RtcB and RtcA have been well characterized, the physiological roles remain largely unresolved. Here we report stress responses that activate expression of the σ 54 -dependent RNA repair operon ( rsr-yrlBA-rtcBA ) of S . Typhimurium and demonstrate that expression of the operon impacts cell survival under MMC-induced stress. Characterization of the requirements for activation of this tightly regulated operon provides clues to the possible functions of operon components in vivo , enhancing our understanding of how this human pathogen copes with environmental stressors.