[Engineering and characterization of new intrinsic transcriptional terminators in Bacillus subtilis 168].

Terminators as regulatory signals are typically placed behind the last coding sequence to block the transcription of DNA to RNA and release the transcript. In the present study, the hairpin and the U-rich sequence of the bacteriophage λto terminator were first modified to investigate their effects on termination efficiency and mRNA stability in Bacillus subtilis 168. Compared with the native λto terminator, the terminator variants M3, M11 and M12 showed higher termination efficiency values. Moreover, the variantsM3, M4 and M11 showed significant positive effects on the mRNA stability of the upstream gfp gene. Additionally, insertion of RNase site also increased the mRNA stability. The results of this study suggested that the composition of the hairpin loop is not required for effective intrinsic termination in B. subtilis. Our results also showed that the terminator could also be used as a potential tool for increasing mRNA stability and the corresponding enzyme production in B. subtilis.