Bacillus subtilis rapD, a direct target of transcription repression by RghR, negatively regulates srfA expression

FEMS Microbiol Lett. 2007 Mar;268(1):73-80. doi: 10.1111/j.1574-6968.2006.00559.x. Epub 2007 Jan 15.


The Bacillus subtilis genome encodes eleven Rap proteins, which are conserved tetratricopeptide-containing regulatory proteins. Of those characterized to date, all except RapI negatively regulate response regulators, including Spo0F, ComA and DegU, via protein-protein interactions. RapD has not yet been fully characterized. It was examined whether RapD inhibits the expression of spoIIE, srfA and aprE, which are Spo0F-, ComA- and DegU-regulated genes, respectively. It was observed that multicopy rapD inhibited srfA expression, which suggests that RapD inhibits ComA. This was reinforced by the fact that multicopy rapD also blocked the expression of rapC and rapF, which belong to the ComA regulon. The expression of rapD was reported to depend on the extracytoplasmic function sigma factor SigX. DNA microarray analysis and gel retardation assays revealed that rapD expression is directly repressed by RghR. Thus, the ComA regulon is regulated by rapD in a SigX- and RghR-dependent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / genetics*
  • Bacillus subtilis / growth & development
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Culture Media
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Electrophoretic Mobility Shift Assay
  • Gene Expression Regulation, Bacterial*
  • Oligonucleotide Array Sequence Analysis
  • Peptide Synthases / genetics
  • Peptide Synthases / metabolism*
  • Regulon / genetics
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Transcription, Genetic*


  • Bacterial Proteins
  • ComA protein, Bacteria
  • Culture Media
  • DNA-Binding Proteins
  • Repressor Proteins
  • Peptide Synthases
  • surfactin synthetase