Crucial roles of MicA and RybB as vital factors for σ-dependent cell lysis in Escherichia coli long-term stationary phase

J Mol Microbiol Biotechnol. 2013;23(3):227-32. doi: 10.1159/000350370. Epub 2013 Apr 16.


σ(E)-dependent cell lysis has been proposed to eliminate damaged cells in the stationary phase in Escherichia coli. In order to explore the relationship of this process to long-term stationary phase existence, we considered that micA and rybB could be important small regulatory RNA (sRNA) genes for σ(E)-dependent cell lysis. A long-term stationary phase was observed at temperatures of <37°C, but not >38°C, and was found even in an rpoS knock-out background. Strains with disrupted micA or rybB were incapable of long-term stationary phase existence. Both strains drastically lost survivability accompanied by a dramatic accumulation of mutations. These findings allow us to speculate that σ(E)-dependent cell lysis plays a key role in the establishment of the long-term stationary phase, presumably by eliminating damaged cells and thus preventing the over-accumulation of mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Glycosylases / genetics
  • DNA Glycosylases / metabolism*
  • Escherichia coli / cytology*
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial
  • Sigma Factor / genetics
  • Sigma Factor / metabolism*


  • Escherichia coli Proteins
  • Sigma Factor
  • DNA Glycosylases
  • mutY adenine glycosylase