Translational Repression of the RpoS Antiadapter IraD by CsrA Is Mediated via Translational Coupling to a Short Upstream Open Reading Frame.

CsrA is a global regulatory RNA binding protein that has important roles in regulating carbon metabolism, motility, biofilm formation, and numerous other cellular processes. IraD functions as an antiadapter protein that inhibits RssB-mediated degradation of RpoS, the general stress response and stationary-phase sigma factor of Here we identified a novel mechanism in which CsrA represses translation via translational coupling. Expression studies with quantitative reverse transcriptase PCR, Western blotting, and fusions demonstrated that CsrA represses expression.

Circuitry Linking the Catabolite Repression and Csr Global Regulatory Systems of Escherichia coli.

Unlabelled: Cyclic AMP (cAMP) and the cAMP receptor protein (cAMP-CRP) and CsrA are the principal regulators of the catabolite repression and carbon storage global regulatory systems, respectively. cAMP-CRP controls the transcription of genes for carbohydrate metabolism and other processes in response to carbon nutritional status, while CsrA binds to diverse mRNAs and regulates translation, RNA stability, and/or transcription elongation. CsrA also binds to the regulatory small RNAs (sRNAs) CsrB and CsrC, which antagonize its activity.

Toxin MqsR cleaves single-stranded mRNA with various 5' ends.

Toxin/antitoxin (TA) systems are the means by which bacterial cells become persistent; that is, those cells that are tolerant to multiple environmental stresses such as antibiotics by becoming metabolically dormant. These persister cells are responsible for recalcitrant infections. Once toxins are activated by the inactivation of antitoxins (e.