Characterization of the Escherichia coli sigma E regulon

J Biol Chem. 2001 Jun 15;276(24):20866-75. doi: 10.1074/jbc.M100464200. Epub 2001 Mar 23.


Escherichia coli responds to the accumulation of misfolded proteins by inducing the transcription of heat shock genes. Efinal sigma(E) RNA polymerase controls one of the two heat shock regulons of E. coli. This regulon is activated upon accumulation of misfolded polypeptides in the double membrane envelope of E. coli. final sigma(E) (RpoE) is a member of the extracytoplasmic function subfamily of sigma factors. Here we asked how many genes are activated by Efinal sigma(E) RNA polymerase and what is the identity of these genes. Using two independent genetic approaches, 20 E. coli promoters were identified which activate reporter gene transcription in a final sigma(E)-dependent manner. In all cases examined, a canonical final sigma(E) binding site could be revealed upon mapping transcriptional start sites. 10 identified promoters activated the transcription of previously identified genes with four genes acting directly on the folding of E. coli envelope proteins (dsbC, fkpA, skp, and surA). The remaining promoters transcribed genes that are presumed to encode hitherto unknown extracytoplasmic functions and were named ecf (ecfA-ecfM). Two of these ecf genes were found to be essential for E. coli growth.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacterial Proteins / genetics
  • Base Sequence
  • Binding Sites
  • DNA-Directed RNA Polymerases / genetics
  • DNA-Directed RNA Polymerases / metabolism
  • Escherichia coli / genetics*
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Regulon / genetics*
  • Sigma Factor / genetics*
  • Sigma Factor / metabolism*
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism*
  • Transcription, Genetic*


  • Bacterial Proteins
  • Sigma Factor
  • Transcription Factors
  • sporulation-specific sigma factors
  • DNA-Directed RNA Polymerases