degS (hhoB) is an essential Escherichia coli gene whose indispensable function is to provide sigma (E) activity

Mol Microbiol. 2001 Jun;40(6):1323-33. doi: 10.1046/j.1365-2958.2001.02475.x.


DegS (HhoB), a putative serine protease related to DegP/HtrA, regulates the basal and induced activity of the essential Escherichia coli sigma factor sigma (E), which is involved in the cellular response to extracytoplasmic stress. DegS promotes the destabilization of the sigma (E)-specific anti-sigma factor RseA, thereby releasing sigma (E) to direct gene expression. We demonstrate that degS is an essential E. coli gene and show that the essential function of DegS is to provide the cell with sigma (E) activity. We also show that the putative active site of DegS is periplasmic and that DegS requires its N-terminal transmembrane domain for its sigma (E)-related function.

Publication types

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

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Base Sequence
  • Cell Membrane / metabolism
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins*
  • Gene Expression Regulation, Bacterial
  • Isopropyl Thiogalactoside / pharmacology
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Molecular Sequence Data
  • Periplasm / metabolism
  • Sigma Factor / genetics
  • Sigma Factor / metabolism*
  • Suppression, Genetic
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Bacterial Proteins
  • DegS protein, Bacteria
  • Escherichia coli Proteins
  • Membrane Proteins
  • RseA protein, E coli
  • Sigma Factor
  • Transcription Factors
  • degS protein, Escherichia coli
  • sporulation-specific sigma factors
  • Isopropyl Thiogalactoside