The RprA RNA gene encodes a 106 nucleotide regulatory non-coding RNA. Translational regulation of the stationary phase sigma factor RpoS is mediated by the formation of a double-stranded RNA stem-loop structure in the upstream region of the rpoS messenger RNA, occluding the translation initiation site. Clones carrying rprA (RpoS regulator RNA A) increased the translation of RpoS. As with DsrA, RprA is predicted to form three stem-loops. Thus, at least two small RNAs, DsrA and RprA, participate in the positive regulation of RpoS translation. RprA also appears to bind to the RpoS leader. RprA is non-essential. Wasserman et al. demonstrated that this RNA is bound by the Hfq protein.