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Symbol SgrS
Rfam RF00534
Other data
RNA type Gene; antisense
Domain(s) Bacteria
GO 0032057 0043488 0030371
SO 0000655

SgrS (sugar transport-related sRNA, previously named ryaA)[1] is a 227 nucleotide small RNA that is activated by SgrR in Escherichia coli during glucose-phosphate stress. The nature of glucose-phosphate stress is not fully understood, but is correlated with intracellular accumulation of glucose-6-phosphate.[2] SgrS helps cells recover from glucose-phosphate stress by base pairing with ptsG mRNA (encoding the glucose transporter) and causing its degradation in an RNase E dependent manner.[3][4] Base pairing between SgrS and ptsG mRNA also requires Hfq, an RNA chaperone frequently required by small RNAs that affect their targets through base pairing.[5] The inability of cells expressing sgrS to create new glucose transporters leads to less glucose uptake and reduced levels of glucose-6-phosphate. SgrS is an unusual small RNA in that it also encodes a 43 amino acid functional polypeptide, SgrT, which helps cells recover from glucose-phosphate stress by preventing glucose uptake. The activity of SgrT does not affect the levels of ptsG mRNA of PtsG protein. It has been proposed that SgrT exerts its effects through regulation of the glucose transporter, PtsG.[6][7]

SgrS was originally discovered in E. coli but homologues have since been identified in other Gammaproteobacteria such as Salmonella enterica and members of the Citrobacter genus.[8] A comparative genomics based target prediction approach that employs these homologs, has been developed and was used to predict the SgrS target, ptsI (b2416), which was subsequently verified experimentally.[9]


  1. ^ Vanderpool, CK; Gottesman S (2004). "Involvement of a novel transcriptional activator and small RNA in post-transcriptional regulation of the glucose phosphoenolpyruvate phosphotransferase system". Mol Microbiol. 54 (4): 1076–1089. PMID 15522088. doi:10.1111/j.1365-2958.2004.04348.x. 
  2. ^ Wadler CS; Vanderpool CK (2007). "A dual function for a bacterial small RNA: SgrS performs base pairing-dependent regulation and encodes a functional polypeptide". PNAS. 104 (51): 20454–9. PMC 2154452Freely accessible. PMID 18042713. doi:10.1073/pnas.0708102104. 
  3. ^ Vanderpool CK; Gottesman S (2007). "The Novel Transcription Factor SgrR Coordinates the Response to Glucose-Phosphate Stress". J. Bact. 189 (2): 2238–2248. PMC 1899371Freely accessible. PMID 17209026. doi:10.1128/JB.01689-06. 
  4. ^ Rice JB; Vanderpool CK (2011). "The small RNA SgrS controls sugar-phosphate accumulation by regulating multiple PTS genes.". Nucleic Acids Res. 39 (9): 3806–3819. PMC 3089445Freely accessible. PMID 21245045. doi:10.1093/nar/gkq1219. 
  5. ^ Kawamoto H; Koide Y; Morita T; Aiba H (2006). "Base-pairing requirement for RNA silencing by a bacterial small RNA and acceleration of duplex formation by Hfq". Mol. Microbiol. 61 (4): 1013–22. PMID 16859494. doi:10.1111/j.1365-2958.2006.05288.x. 
  6. ^ Maki K; Morita T; Otaka H; Aiba H (2010). "A minimal base-pairing region of a bacterial small RNA SgrS required for translational repression of ptsG mRNA". Mol Microbiol. 76 (3): 782–92. PMID 20345651. doi:10.1111/j.1365-2958.2010.07141.x. 
  7. ^ Kawamoto, H; Morita T; Shimizu A; Inada T; Aiba H (2005). "Implication of membrane localization of target mRNA in the action of a small RNA: mechanism of post-transcriptional regulation of glucose transporter in Escherichia coli". Genes Dev. 19 (3): 328–338. PMC 546511Freely accessible. PMID 15650111. doi:10.1101/gad.1270605. 
  8. ^ Horler RS; Vanderpool CK (September 2009). "Homologs of the small RNA SgrS are broadly distributed in enteric bacteria but have diverged in size and sequence". Nucleic Acids Res. 37 (16): 5465–76. PMC 2760817Freely accessible. PMID 19531735. doi:10.1093/nar/gkp501. Retrieved 2010-09-02. 
  9. ^ Wright PR; Richter AS; Papenfort K; Mann M; Vogel J; Hess WR; Backofen R; Georg J (2013). "Comparative genomics boosts target prediction for bacterial small RNAs.". Proc Natl Acad Sci U S A. 110 (37): E3487–E3496. PMC 3773804Freely accessible. PMID 23980183. doi:10.1073/pnas.1303248110. 

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