Localization of a second SigH promoter in the Bacillus subtilis sigA operon and regulation of dnaE expression by the promoter.

AUTOR(ES)

Qi, F X

RESUMO

The presence of a second SigH promoter in the sigA operon of Bacillus subtilis was demonstrated by use of a promoter probe plasmid, a sigH deletion mutant, primer extension studies, and in vitro transcription with E sigma H holoenzyme. Both SigH promoters were expressed at low levels even during the growth phase but were expressed at higher levels during the early stationary phase. Expression from the upstream SigH promoter allowed the expression of both dnaE and sigA genes; however, expression from the downstream SigH promoter, which was located in the ribosome-binding site of the dnaE gene, resulted only in the expression of the sigA gene, since the truncated dnaE ribosome-binding site could not be used for initiating translation. Thus, promoter switching during the early stationary phase resulted not only in expression from SigH promoters but also in differential expression of the genes in the sigA operon.

Documentos Relacionados

• Localization of a new promoter, P5, in the sigA operon of Bacillus subtilis and its regulation in some spo mutant strains.
• The response of a Bacillus subtilis temperature-sensitive sigA mutant to heat stress.
• Transcriptional regulation of the Bacillus subtilis menp1 promoter.
• The sigma B-dependent promoter of the Bacillus subtilis sigB operon is induced by heat shock.
• Bacillus subtilis pur operon expression and regulation.