Regulated expression of the dinR and recA genes during competence development and SOS induction in Bacillus subtilis

Mol Microbiol. 1996 Oct;22(1):75-85. doi: 10.1111/j.1365-2958.1996.tb02657.x.


It has been hypothesized that the dinR gene product of Bacillus subtilis acts as a repressor of the SOS regulon by binding to DNA sequences located upstream of SOS genes, including dinR and recA. Following activation as a result of DNA damage, RecA is believed to catalyse DinR-autocleavage, thus derepressing the SOS regulon. The present results support this hypothesis: a dinR insertion mutation caused a high, constitutive expression of both dinR and recA, which could not be further elevated by SOS-induction. In addition, gel-retardation assays demonstrated a direct interaction between the dinR gene product and the recA and dinR promoter regions. Epistatic interactions and gel-retardation assays demonstrated that the previously reported competence-specific expression of recA directly depended upon the gene product of comK, the competence transcription factor. These data demonstrate the existence of a direct regulatory link between the competence signal-transduction pathway and the SOS reguion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / genetics*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Blotting, Southern
  • Blotting, Western
  • DNA Footprinting
  • Epistasis, Genetic
  • Gene Expression Regulation, Bacterial*
  • Genes, Reporter
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic
  • Protein Binding
  • Rec A Recombinases / genetics
  • Rec A Recombinases / metabolism*
  • Recombinant Fusion Proteins / metabolism
  • Repressor Proteins
  • SOS Response, Genetics / genetics*
  • Sequence Analysis, DNA
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription, Genetic


  • Bacterial Proteins
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Transcription Factors
  • dinR protein, Bacillus subtilis
  • comK protein, Bacillus subtilis
  • Rec A Recombinases