Promoter strength properties of the complete sigma E regulon of Escherichia coli and Salmonella enterica.

ABSTRACT: The sigma(E)-directed envelope stress response maintains outer membrane homeostasis and is an important virulence determinant upon host infection in Escherichia coli and related bacteria. sigma(E) is activated by at least two distinct mechanisms: accumulation of outer membrane porin precursors and an increase in the alarmone ppGpp upon transition to stationary phase. Expression of the sigma(E) regulon is driven from a suite of approximately 60 sigma(E)-dependent promoters. Using green fluorescent protein fusions to each of these promoters, we dissected promoter contributions to the output of the regulon under a variety of in vivo conditions. We found that the sigma(E) promoters exhibit a large dynamic range, with a few strong and many weak promoters. Interestingly, the strongest promoters

SUBMITTER: Mutalik VK 

PROVIDER: S-EPMC2786571 | biostudies-literature | 2009 Dec

REPOSITORIES: biostudies-literature