Biology:SgrS RNA

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SgrS RNA
RF00534.jpg
Predicted secondary structure and sequence conservation of SgrS
Identifiers
SymbolSgrS
RfamRF00534
Other data
RNA typeGene; antisense
Domain(s)Bacteria
GO0032057 0043488 0030371
SO0000655
PDB structuresPDBe

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.[2] 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 genus Citrobacter.[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]

References

  1. "Involvement of a novel transcriptional activator and small RNA in post-transcriptional regulation of the glucose phosphoenolpyruvate phosphotransferase system". Molecular Microbiology 54 (4): 1076–89. November 2004. doi:10.1111/j.1365-2958.2004.04348.x. PMID 15522088. 
  2. 2.0 2.1 "A dual function for a bacterial small RNA: SgrS performs base pairing-dependent regulation and encodes a functional polypeptide". Proceedings of the National Academy of Sciences of the United States of America 104 (51): 20454–9. December 2007. doi:10.1073/pnas.0708102104. PMID 18042713. 
  3. "The novel transcription factor SgrR coordinates the response to glucose-phosphate stress". Journal of Bacteriology 189 (6): 2238–48. March 2007. doi:10.1128/JB.01689-06. PMID 17209026. 
  4. "The small RNA SgrS controls sugar-phosphate accumulation by regulating multiple PTS genes". Nucleic Acids Research 39 (9): 3806–19. May 2011. doi:10.1093/nar/gkq1219. PMID 21245045. 
  5. "Base-pairing requirement for RNA silencing by a bacterial small RNA and acceleration of duplex formation by Hfq". Molecular Microbiology 61 (4): 1013–22. August 2006. doi:10.1111/j.1365-2958.2006.05288.x. PMID 16859494. 
  6. "A minimal base-pairing region of a bacterial small RNA SgrS required for translational repression of ptsG mRNA". Molecular Microbiology 76 (3): 782–92. May 2010. doi:10.1111/j.1365-2958.2010.07141.x. PMID 20345651. 
  7. "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 & Development 19 (3): 328–38. February 2005. doi:10.1101/gad.1270605. PMID 15650111. 
  8. "Homologs of the small RNA SgrS are broadly distributed in enteric bacteria but have diverged in size and sequence". Nucleic Acids Research 37 (16): 5465–76. September 2009. doi:10.1093/nar/gkp501. PMID 19531735. 
  9. "Comparative genomics boosts target prediction for bacterial small RNAs". Proceedings of the National Academy of Sciences of the United States of America 110 (37): E3487-96. September 2013. doi:10.1073/pnas.1303248110. PMID 23980183. Bibcode2013PNAS..110E3487W. 

Further reading

External links