The computational search for promoters in prokaryotes remains an attractive problem in bioinformatics. Despite the attention it has received for many years, the problem has not been addressed satisfactorily. In any bacterial genome, the transcription start site is chosen mostly by the sigma (xcfx83) factor proteins, which control the gene activation. The majority of published bacterial promoter prediction tools target xcfx83 70 promoters in Escherichia coli . Moreover, no xcfx83-specific classification of promoters is available for prokaryotes other than for E. coli .