Small noncoding RNA GcvB is a novel regulator of acid resistance in Escherichia coli

BMC Genomics. 2009 Apr 20;10:165. doi: 10.1186/1471-2164-10-165.


Background: The low pH environment of the human stomach is lethal for most microorganisms; but not Escherichia coli, which can tolerate extreme acid stress. Acid resistance in E. coli is hierarchically controlled by numerous regulators among which are small noncoding RNAs (sncRNA).

Results: In this study, we individually deleted seventy-nine sncRNA genes from the E. coli K12-MG1655 chromosome, and established a single-sncRNA gene knockout library. By systematically screening the sncRNA mutant library, we show that the sncRNA GcvB is a novel regulator of acid resistance in E. coli. We demonstrate that GcvB enhances the ability of E. coli to survive low pH by upregulating the levels of the alternate sigma factor RpoS.

Conclusion: GcvB positively regulates acid resistance by affecting RpoS expression. These data advance our understanding of the sncRNA regulatory network involved in modulating acid resistance in E. coli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial
  • Gene Knockout Techniques
  • Hydrogen-Ion Concentration
  • Lipoproteins / genetics
  • Lipoproteins / metabolism
  • Mutation
  • RNA, Untranslated / genetics
  • RNA, Untranslated / metabolism*
  • Sigma Factor / genetics
  • Sigma Factor / metabolism


  • Bacterial Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • Lipoproteins
  • OppA protein, E coli
  • RNA, Untranslated
  • Sigma Factor
  • sigma factor KatF protein, Bacteria