OmrA-B RNA

OmrA-B RNA
A representation of the bacterial OmrA-B secondary structure including a colour scheme that indicates the degree of sequence conservation.
Identifiers
Symbol	OmrA-B
Alt. Symbols	OmrA, OmrB, SraE, RygA, RygB
Rfam	RF00079
Other data
RNA type	Gene
Domain(s)	Bacteria; Enterobacteriaceae

The OmrA-B RNA gene family (also known as SraE RNA, RygA and RygB and OmrA and OmrB) is a pair of homologous OmpR-regulated small non-coding RNA that was discovered in E. coli during two large scale screens.^[1][2] OmrA-B is highly abundant in stationary phase, but low levels could be detected in exponentially growing cells as well. RygB is adjacent to RygA a closely related RNA. These RNAs bind to the Hfq protein and regulate gene expression by antisense binding. They negatively regulate the expression of several genes encoding outer membrane proteins, including cirA, CsgD, fecA, fepA and ompT by binding in the vicinity of the Shine-Dalgarno sequence, suggesting the control of these targets is dependent on Hfq protein and RNase E. Taken together, these data suggest that OmrA-B participates in the regulation of outer membrane composition, responding to environmental conditions.^[3][4][5]

References

1. ^ Argaman, L; Hershberg R, Vogel J, Bejerano G, Wagner EG, Margalit H, Altuvia S (2001). "Novel small RNA-encoding genes in the intergenic regions of Escherichia coli". Curr Biol 11 (12): 941–950. doi:10.1016/S0960-9822(01)00270-6. PMID 11448770. 
2. ^ Wassarman, KM; Repoila F, Rosenow C, Storz G, Gottesman S (2001). "Identification of novel small RNAs using comparative genomics and microarrays". Genes Dev 15 (13): 1637–1651. doi:10.1101/gad.901001. PMC 312727. PMID 11445539. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=312727. 
3. ^ Guillier M, Gottesman S (2006). "Remodelling of the Escherichia coli outer membrane by two small regulatory RNAs.". Mol Microbiol 59 (1): 231–47. doi:10.1111/j.1365-2958.2005.04929.x. PMID 16359331. 
4. ^ Guillier M, Gottesman S (2008). "The 5' end of two redundant sRNAs is involved in the regulation of multiple targets, including their own regulator.". Nucleic Acids Res 36 (21): 6781–94. doi:10.1093/nar/gkn742. PMC 2588501. PMID 18953042. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2588501. 
5. ^ Holmqvist E, Reimegård J, Sterk M, Grantcharova N, Römling U, Wagner EG (2010). "Two antisense RNAs target the transcriptional regulator CsgD to inhibit curli synthesis.". EMBO J 29 (11): 1840–50. PMID 20407422. 

External links

• Rfam page for OmrA-B RNA
• EcoGene entry for OmrA and OmrB
• EcoliWiki entry for OmrA and OmrB