|Gene:||omrA||Accession Numbers: G0-8868 (EcoCyc), b4444, ECK2833|
Synonyms: psrA12, rygA, PAIR2a, t59, sraE
Superclasses: a regulatory RNA
OmrA is a small RNA of approximately 88 nt in length [Argaman01, Wassarman01] that is involved in regulating the protein composition of the outer membrane [Guillier06]. OmrA was shown to negatively regulate the levels of ompT, cirA, fecA, fepA [Guillier06], ompR [Guillier08], csgD [Holmqvist10], and flhDC [De12] mRNAs. The effect of OmrA on ompT and cirA abundance is dependent on RNase E and involves direct base pairing at the 5' end of OmrA [Guillier08]. A set of targets for regulation by OmrA has been predicted, but only a small percentage of those possible targets was supported by microarray data [Tjaden06].
OmrA and OmrB were first recognized as an intergenic duplication (PAIR2) containing sites that resemble Rho-independent terminators [Rudd99]. The 5' and 3' ends of OmrA and OmrB are nearly identical, but their central regions differ.
OmrA is highly abundant in stationary phase cells grown in LB medium [Argaman01, Wassarman01, Zhang03d]. The half life of OmrA in stationary phase is 16 minutes [Vogel03]. Transcription of omrA is regulated by OmpR [Guillier06].
The 5' end of OmrA is required for the regulatory function of the small RNA [Guillier08]. An omrAB deletion mutant shows a change in the protein composition of the outer membrane [Guillier06]. Overexpression of omrA inhibits the formation of curli by downregulating CsgD expression [Holmqvist10].
SraE: "small RNA", PsrA12: "predicted small RNA" [Argaman01]
Ryx: "RNA of unknown function at X position (10 minute) in the genome" [Wassarman01]
OmrA: "OmpR-regulated sRNA A" [Guillier06]
|Map Position: [2,974,124 <- 2,974,211] (64.1 centisomes, 231°)||Length: 88 bp|
|Biological Process:||GO:0040033 - negative regulation of translation, ncRNA-mediated [Holmqvist10]|
|Molecular Function:||GO:0000499 - base pairing with mRNA
GO:0005515 - protein binding [Wassarman01]
|MultiFun Terms:||information transfer → RNA related → antisense RNA|
|information transfer → RNA related → RNA degradation|
Argaman01: 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);941-50. PMID: 11448770
Guillier08: 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. PMID: 18953042
Holmqvist10: Holmqvist E, Reimegard J, Sterk M, Grantcharova N, Romling U, Wagner EG (2010). "Two antisense RNAs target the transcriptional regulator CsgD to inhibit curli synthesis." EMBO J 29(11);1840-50. PMID: 20407422
Vogel03: Vogel J, Bartels V, Tang TH, Churakov G, Slagter-Jager JG, Huttenhofer A, Wagner EG (2003). "RNomics in Escherichia coli detects new sRNA species and indicates parallel transcriptional output in bacteria." Nucleic Acids Res 31(22);6435-43. PMID: 14602901
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