A novel regulatory protein governing biofilm formation in Bacillus subtilis

Mol Microbiol. 2008 Jun;68(5):1117-27. doi: 10.1111/j.1365-2958.2008.06201.x. Epub 2008 Apr 21.


Production of an extracellular matrix is a hallmark of biofilm formation. In the spore-forming bacterium Bacillus subtilis, the matrix consists of an exopolysaccharide, which is specified by the epsA-O operon, and a secreted protein TasA, which is encoded by the yqxM-sipW-tasA operon. Past and present evidence establish that the epsA-O and yqxM-sipW-tasA operons are controlled by the repressor proteins SinR and AbrB. Here, we report the identification of a novel regulatory protein Slr that promotes transcription of the yqxM-sipW-tasA operon but is not needed for expression of the epsA-O operon. We further show that the gene for Slr is itself under the negative control of SinR and AbrB. These findings reveal that matrix production is governed by an intricate network involving the interplay of negatively and positively acting regulatory proteins.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism
  • Bacillus subtilis / physiology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / physiology*
  • Biofilms / growth & development*
  • Gene Expression Regulation, Bacterial
  • Operon / genetics*
  • Polysaccharides, Bacterial / genetics
  • Polysaccharides, Bacterial / metabolism*
  • Transcription Factors / metabolism
  • Transcription, Genetic


  • Bacterial Proteins
  • Polysaccharides, Bacterial
  • TasA protein, Bacillus subtilis
  • Transcription Factors
  • exopolysaccharide, Bacillus