EcfE, a new essential inner membrane protease: its role in the regulation of heat shock response in Escherichia coli

EMBO J. 2001 Nov 1;20(21):5908-18. doi: 10.1093/emboj/20.21.5908.


We have identified a new protease in Escherichia coli, which is required for its viability under normal growth conditions. This protease is anchored in the inner membrane and the gene encoding it has been named ecfE, since it is transcribed by Esigma(E) polymerase. Multicopy expression of the ecfE gene was found to turn down expression of both Esigma(E)- and Esigma(32)-transcribed promoters. Purified EcfE degrades both heat shock sigma factors RpoE and RpoH in vitro. EcfE has a zinc binding domain at the N-terminus, a PDZ-like domain in the middle and a highly conserved tripeptide, LDG, at the C-terminus. These features are characteristic of members of a new class of proteases whose activity occurs close to the inner membrane or within the inner membrane. Temperature-sensitive mutants of this gene were isolated mapping to the catalytic site and other domains that exhibited constitutively elevated levels of both heat shock regulons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Arabinose / pharmacology
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Binding Sites / physiology
  • Electrophoresis, Polyacrylamide Gel
  • Endopeptidases / chemistry*
  • Endopeptidases / genetics
  • Endopeptidases / metabolism*
  • Enzyme Induction / drug effects
  • Enzyme Induction / physiology
  • Enzyme Stability / physiology
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Escherichia coli / growth & development
  • Escherichia coli Proteins*
  • Gene Expression Regulation, Bacterial
  • Heat-Shock Proteins / metabolism
  • Heat-Shock Response / physiology*
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Mutagenesis, Insertional
  • Mutagenesis, Site-Directed
  • Polysaccharides / metabolism
  • Protein Structure, Tertiary / physiology
  • Sigma Factor / metabolism
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Temperature
  • Transcription Factors / metabolism
  • Zinc / metabolism


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Heat-Shock Proteins
  • Membrane Proteins
  • Polysaccharides
  • Sigma Factor
  • Transcription Factors
  • heat-shock sigma factor 32
  • sporulation-specific sigma factors
  • colanic acid
  • Arabinose
  • Endopeptidases
  • RseP protein, E coli
  • Zinc