Tandem genes encoding sigma-factors for consecutive steps of development in Bacillus subtilis.
During sporulation, Bacillus subtilis undergoes successive morphological changes that can be arrested at various stages by mutations in many genes. One of these, spoIIGB, encodes a transcriptional factor, sigma E, which is necessary to proceed beyond stage II and to differentiate the cell in two compartments, the forespore and the mother cell. Mutations were introduced in an open reading frame located immediately downstream of spoIIGB. They block sporulation at stage III and define a new gene, spoIIIG, encoding a 260-amino-acid polypeptide highly similar to bacterial sigma-factors. A promoter was identified in the spoIIGB-spoIIIG interval by transcriptional fusion to lacZ. It is turned on 1 hr after the start of sigma E synthesis and is specifically activated in the forespore. The tandemly arranged spoIIGB and spoIIIG genes appear to encode homologous proteins that modulate transcription in a sequential fashion during sporulation.
Karmazyn-Campelli
C
C
Institut de Microbiologie, Université Paris-Sud, Orsay, France.
Bonamy
C
C
Savelli
B
B
Stragier
P
P
D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D009876:Operon; D012808:Sigma Factor / Q000235:genetics*; D013171:Spores, Bacterial / Q000254:growth & development; D014157:Transcription Factors / Q000235:genetics*
D001426:Bacterial Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus