Identification of a promoter for the vegetative insecticidal protein-encoding gene vip3LB from Bacillus thuringiensis

The expression of vip3LB, one of the vegetative insecticidal protein-encoding genes of Bacillus thuringiensis, was studied at the transcriptional level. By primer extension analysis, we have identified, for the first time, the transcription start point of vip3-type gene. Upstream from vip3LB transcription start point, was found a nucleotide sequence partially homologous to the consensus sequence for the E σE holoenzyme of B. subtilis. Thus, it was strongly suggested that the identified vip3 promoter was under the control of σ35-like enzyme, the B. thuringiensis homolog of σE. The transcriptional activity from the promoter was detected at the vegetative stage of growth starting at mid-log phase as well as during the middle stage of sporulation.