ppGpp: a global regulator in Escherichia coli

Trends Microbiol. 2005 May;13(5):236-42. doi: 10.1016/j.tim.2005.03.008.


The small nucleotide ppGpp acts as a global regulator of gene expression in bacteria. Proteomic analysis of cells lacking ppGpp has shown that this nucleotide might affect many more genes than previously anticipated. These findings and others suggest that ppGpp causes a redirection of transcription so that genes important for starvation survival and virulence are favoured at the expense of those required for growth and proliferation. In addition, new insights into the mechanism by which ppGpp affects gene expression have been achieved owing to in vitro studies of ppGpp function, complemented by structural studies of the ppGpp-RNA polymerase complex.

Publication types

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

MeSH terms

  • DNA-Directed RNA Polymerases / metabolism*
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial / physiology*
  • Guanosine Tetraphosphate / metabolism*
  • Promoter Regions, Genetic / physiology
  • Sigma Factor / metabolism


  • Escherichia coli Proteins
  • Sigma Factor
  • dksA protein, E coli
  • Guanosine Tetraphosphate
  • RNA polymerase sigma 70
  • DNA-Directed RNA Polymerases