Identification and nucleotide sequence of the promoter region of the Bacillus subtilis gluconate operon

The nucleotide sequence (742 bp) of the promoter region of the Bacillus subtilis gluconate (gnt) operon is presented. Nuclease Sl mapping revealed the start point of the transcription and suggested that the expression of this operon is probably regulated at the transcriptional level. The sequences of the -35 and -10 regions suggested that RNA polymerase possessing sigma-43 may recognize this structure. The 223 bp fragment containing 100 bp upstream from the transcription start site actually exhibited a promoter activity when cloned in a promoter probe vector of pPL603B. This promoter activity was highly derepressed and although still under catabolite repression. The fragment on a high copy plasmid could titrate a regulator of the gnt operon so that the expression of the operon on the host chromosome also became derepressed.