Mechanism of NusG-stimulated pausing, hairpin-dependent pause site selection and intrinsic termination at overlapping pause and termination sites in the Bacillus subtilis trp leader.

ABSTRACT: The Bacillus subtilis trpEDCFBA operon is regulated by TRAP-dependent transcription attenuation and translation repression mechanisms. Previous results showed that NusA and NusG cooperatively stimulate RNA polymerase pausing at U107 and U144 in the trp leader, and that NusG is required for pausing at U144 in vivo. Pausing at U107 and U144 participate in the attenuation and translation repression mechanisms, respectively, by providing additional time for TRAP binding. The intrinsic trp leader terminator overlaps the hairpin-dependent U144 pause site. Here, we conducted a systematic mutational analysis of the terminator/pause region. Deletion of the hairpin reduced pausing but did not affect pause site selection. Thus, hairpin-stimulated pausing is a more appropriate term than hairpin-depend

SUBMITTER: Yakhnin AV 

PROVIDER: S-EPMC2919817 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature