Analysis of the Regulation and Function of Five Genes Encoding Small, Acid-Soluble Spore Proteins of Bacillus Subtilis

Gene. 2000 May 2;248(1-2):169-81. doi: 10.1016/s0378-1119(00)00125-6.


Four genes [sspI, sspK, sspM, and sspO (originally called cotK)] encoding minor small, acid-soluble proteins (SASP) unique to spores of Bacillus subtilis are expressed only in the forespore compartment of sporulating cells of this organism. The sspI, sspK and sspM genes are monocistronic, while sspO is the first gene in a likely operon with sspP (originally called cotL), which also encodes a putative very small protein. Transcription of these genes is primarily, if not exclusively, by RNA polymerase with the forespore-specific sigma factor, sigma(G). Sequences centered 10 and 35nt upstream of the 5'-ends of sspI, sspK, sspM and sspO also show homology to the -10 and -35 sequences recognized by sigma(G). Mutations deleting these genes cause the loss of the appropriate SASP from spores, and the sspK, sspM and sspO (and likely sspP) mutations had no discernable effect on sporulation, spore properties or spore germination. Loss of sspI also had no effect on sporulation, spore properties or spore germination, but DeltasspI spores had a significant defect in spore outgrowth.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Bacillus subtilis / genetics*
  • Bacillus subtilis / physiology
  • Bacterial Proteins / genetics*
  • Base Sequence
  • DNA, Recombinant / genetics
  • Gene Deletion
  • Gene Expression Regulation, Bacterial*
  • Lac Operon / genetics
  • Molecular Sequence Data
  • Mutation
  • Plasmids
  • Promoter Regions, Genetic
  • Sigma Factor*
  • Spores, Bacterial / metabolism
  • Transcription Factors*
  • Transcription, Genetic


  • Bacterial Proteins
  • DNA, Recombinant
  • Sigma Factor
  • Transcription Factors
  • spoIIR protein, Bacillus subtilis
  • spore-specific proteins, Bacillus