The secret to 6S: regulating RNA polymerase by ribo-sequestration

Mol Microbiol. 2009 Jul;73(2):137-40. doi: 10.1111/j.1365-2958.2009.06759.x. Epub 2009 Jun 17.

Abstract

Regulating transcription under different conditions is vital to all organisms. As Escherichia coli shifts from exponential to stationary growth, regulation of transcription is achieved in large part by the tight binding of 6S RNA to Esigma(70), RNA polymerase with the sigma(70) specificity subunit. Ribo-sequestration of Esigma(70) by 6S RNA serves to downregulate sigma(70)-dependent transcription, which is needed for exponential growth. This facilitates transcription from promoters dependent on stationary phase sigma, sigma(s). Previous work has suggested that the 6S RNA binding to Esigma(70) simply mimics the Esigma(70)/promoter interaction. In this issue of Molecular Microbiology, Klocko and Wassarman demonstrate that many of the contacts between residues within sigma(70) region 4 and 6S RNA are distinct from those between region 4 and promoter DNA. Several residues that interact with 6S RNA are ones previously known to interact with protein activators of Esigma(70). Their work adds 6S RNA to the growing list of factors that can regulate Esigma(70) by interacting with region 4.

Publication types

  • Research Support, N.I.H., Intramural
  • Comment

MeSH terms

  • Binding Sites
  • DNA, Bacterial / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism*
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial
  • Promoter Regions, Genetic
  • RNA, Bacterial / metabolism*
  • RNA, Untranslated
  • Sigma Factor / genetics
  • Sigma Factor / metabolism*

Substances

  • 6S RNA
  • DNA, Bacterial
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • RNA, Bacterial
  • RNA, Untranslated
  • Sigma Factor
  • RNA polymerase sigma 70
  • DNA-Directed RNA Polymerases