Regulation of competence-specific gene expression by Mec-mediated protein- protein interaction in Bacillus subtilis

L. Kong, D. Dubnau

Research output: Contribution to journalArticle

64 Scopus citations


The expression of competence genes in Bacillus subtilis is controlled by a signal transduction cascade which increases the expression of a competence transcription factor (CTF, encoded by comK) during the transition from exponential growth to stationary phase. The transcription of CTF (ComK) is decreased by the product of the mecA gene, and this inhibition is relieved in response to an unknown signal received from upstream in the regulatory pathway. Inactivation of either mecA or another gene, mecB, results in overproduction of ComK. We show here that the concentration of MecA protein does not vary markedly with culture medium, as a function of growth stage, or in competent and noncompetent cells. We also show that MecA can interact directly with ComK. Finally, evidence is presented suggesting that MecB functions prior to MecA in the signaling pathway. A model is discussed which involves the sequestration of ComK by MecA binding and the release of the transcription factor when an appropriate signal is relayed to MecA by MecB.

Original languageEnglish (US)
Pages (from-to)5793-5797
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number13
StatePublished - Jun 29 1994


All Science Journal Classification (ASJC) codes

  • General


  • global regulation
  • signal transduction
  • transformation

Cite this