Targeting of csgD by the small regulatory RNA RprA links stationary phase, biofilm formation and cell envelope stress in Escherichia coli.

ABSTRACT: RprA is a small regulatory RNA known to weakly affect the translation of σ(S) (RpoS) in Escherichia coli. Here we demonstrate that csgD, which encodes a stationary phase-induced biofilm regulator, as well as ydaM, which encodes a diguanylate cyclase involved in activating csgD transcription, are novel negatively controlled RprA targets. As shown by extensive mutational analysis, direct binding of RprA to the 5'-untranslated and translational initiation regions of csgD mRNA inhibits translation and reduces csgD mRNA levels. In the case of ydaM mRNA, RprA base-pairs directly downstream of the translational start codon. In a feedforward loop, RprA can thus downregulate > 30 YdaM/CsgD-activated genes including those for adhesive curli fimbriae. However, during early stationary phase, when csg

SUBMITTER: Mika F 

PROVIDER: S-EPMC3465796 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature