Expression of a small RNA, BS203 RNA, from the yocI–yocJ intergenic region of Bacillus subtilis genome

Abstract We isolated and characterized a novel small RNA from Bacillus subtilis. We termed this molecule BS203 RNA from the length of its mature form (203 nt) and located the corresponding gene at the yocI–yocJ intergenic region on the B. subtilis genome. Northern blotting revealed that it is transcribed in vegetative growing cells and that the amount of BS203 RNA decreased in the middle of the vegetative phase. A computer-aided prediction of the BS203 RNA secondary structure revealed three characteristic stem–loop structures. Despite active expression during the vegetative phase, growth of the knockout mutant was not affected by depletion of BS203 RNA. A phylogenetic comparison of the sequence of the BS203 RNA with other Bacillus species including B. cereus and B. halodurans C-125, or Clostridium perfringens suggests that the sequence is unique to Bacillus subtilis.