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.[1][2]
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.[3] RprA is non-essential.[4] Wasserman et al. demonstrated that this RNA is bound by the Hfq protein.[5] Binding to Hfq alters the conformation of RprA.[6] In the presence of Hfq the stability of RprA is influenced by the osmolarity of the cell, this is dependent on the endoribonucleaseRNase E.[7]
It has been shown the RprA regulates the protein coding genes, called csgD, this protein encodes a stationary phase-induced biofilm regulator and ydaM, which encodes a diguanylate cyclase involved in activating csgD transcription. These two target genes are repressed by RprA which results in regulation of biofilm formation.[8]
References
^Updegrove T, Wilf N, Sun X, Wartell RM (2008). "Effect of Hfq on RprA-rpoS mRNA pairing: Hfq-RNA binding and the influence of the 5′ rpoS mRNA leader region". Biochemistry. 47 (43): 11184–11195. doi:10.1021/bi800479p. PMID18826256.
^Madhugiri R, Basineni SR, Klug G (2010). "Turn-over of the small non-coding RNA RprA in E. coli is influenced by osmolarity". Mol Genet Genomics. 284 (4): 307–318. doi:10.1007/s00438-010-0568-x. PMID20717695. S2CID23732166.
