Mechanism for coordinate regulation ofrpoSby sRNA-sRNA interaction inEscherichia coli

RpoS is a key regulator of general stress responses in Escherichia coli. Its expression is post-transcriptionally up-regulated by the small RNAs (sRNAs), ArcZ, DsrA and RprA, through sRNA-rpoS mRNA interactions. Although overexpression of the sRNA, CyaR, was reported to down-regulate rpoS expression, how CyaR regulates rpoS has not been determined. Here, we report that CyaR represses rpoS expression by base-pairing with a region next to the ArcZ...