Hydrophobicity of Residue 128 of the Stress-Inducible Sigma Factor RpoS Is Critical for Its Activity.

ABSTRACT: RpoS is a key stress-inducible sigma factor that regulates stress resistance genes in Escherichia coli, such as the katE gene encoding catalase HPII and the glg genes encoding glycogen synthesis proteins. Monitoring RpoS activity can provide information on the stress sensitivity of E. coli isolates in clinical settings because the RpoS in these isolates is often mutated. In the present study, we found a novel, missense point mutation at RpoS residue 128 in a clinical Shiga toxin-producing E. coli (STEC) isolate. This mutation caused RpoS dysfunction and increased stress sensitivity. A mutant rpoS was cloned from a clinical STEC that is vulnerable to cold temperature and oxidative stresses. Mutant RpoS protein expression was detected in the clinical

SUBMITTER: Iwase T 

PROVIDER: S-EPMC5405132 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature