Targets of the master regulator of biofilm formation in Bacillus subtilis

Mol Microbiol. 2006 Feb;59(4):1216-28. doi: 10.1111/j.1365-2958.2005.05019.x.


Wild strains of the spore-forming bacterium Bacillus subtilis are capable of forming architecturally complex communities of cells. The formation of these biofilms is mediated in part by the 15-gene exopolysaccharide operon, epsA-O, which is under the direct negative control of the SinR repressor. We report the identification of an additional operon, yqxM-sipW-tasA, that is required for biofilm formation and is under the direct negative control of SinR. We now show that all three members of the operon are required for the formation of robust biofilms and that SinR is a potent repressor of the operon that acts by binding to multiple sites in the promoter region. Genome-wide analysis of SinR-controlled transcription indicates that the epsA-O and yqxM-sipW-tasA operons constitute many of the most strongly controlled genes in the SinR regulon. These findings reinforce the view that SinR is a master regulator for biofilm formation and further suggest that a principal biological function of SinR is to govern the assembly of complex multicellular communities.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

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


  • Bacterial Proteins
  • Polysaccharides, Bacterial
  • Repressor Proteins
  • TasA protein, Bacillus subtilis
  • exopolysaccharide, Bacillus
  • FlaD protein, Bacteria