Interactions between the 2.4 and 4.2 regions of sigmaS, the stress-specific sigma factor of Escherichia coli, and the -10 and -35 promoter elements.

ABSTRACT: The sigmas subunit of Escherichia coli RNA polymerase holoenzyme (EsigmaS) is a key factor of gene expression upon entry into stationary phase and in stressful conditions. The selectivity of promoter recognition by EsigmaS and the housekeeping Esigma70 is as yet not clearly understood. We used a genetic approach to investigate the interaction of sigmaS with its target promoters. Starting with down-promoter variants of a sigmaS promoter target, osmEp, altered in the -10 or -35 elements, we isolated mutant forms of sigmaS suppressing the promoter defects. The activity of these suppressors on variants of osmEp and ficp, another target of sigmaS, indicated that sigmaS is able to interact with the same key features within a promoter sequence as sigma70. Indeed, (i) sigmaS can recognize the -35

SUBMITTER: Checroun C 

PROVIDER: S-EPMC373267 | biostudies-literature | 2004

REPOSITORIES: biostudies-literature