Two promoters and two translation start sites control the expression of the Shigella flexneri outer membrane protease IcsP.

ABSTRACT: The Shigella flexneri outer membrane protease IcsP proteolytically cleaves the actin-based motility protein IcsA from the bacterial surface. The icsP gene is monocistronic and lies downstream of an unusually large intergenic region on the Shigella virulence plasmid. In silico analysis of this region predicts a second transcription start site 84 bp upstream of the first. Primer extension analyses and beta-galactosidase assays demonstrate that both transcription start sites are used. Both promoters are regulated by the Shigella virulence gene regulator VirB and both respond similarly to conditions known to influence Shigella virulence gene expression (iron concentration, pH, osmotic pressure, and phase of growth). The newly identified promoter lies upstream of a Shine-Dalgarno sequence and s

SUBMITTER: Hensley CT 

PROVIDER: S-EPMC3071033 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature