Bacterial regulon evolution: distinct responses and roles for the identical OmpR proteins of Salmonella Typhimurium and Escherichia coli in the acid stress response.

ABSTRACT: The evolution of new gene networks is a primary source of genetic innovation that allows bacteria to explore and exploit new niches, including pathogenic interactions with host organisms. For example, the archetypal DNA binding protein, OmpR, is identical between Salmonella Typhimurium serovar Typhimurium and Escherichia coli, but regulatory specialization has resulted in different environmental triggers of OmpR expression and largely divergent OmpR regulons. Specifically, ompR mRNA and OmpR protein levels are elevated by acid pH in S. Typhimurium but not in E. coli. This differential expression pattern is due to differences in the promoter regions of the ompR genes and the E. coli ompR orthologue can be made acid-inducible by introduction of the appropriate sequences from S. Typhimurium.

SUBMITTER: Quinn HJ 

PROVIDER: S-EPMC3945435 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature