NusA-stimulated RNA polymerase pausing and termination participates in the Bacillus subtilis trp operon attenuation mechanism in vitro

摘要

The trp RNA-binding attenuation protein (TRAP) regulates expres- sion of the Bacillus subtilis trpEDCFBA operon by transcription attenuation and translation control mechanisms. Both mechanisms require the binding of tryptophan-activated TRAP to the 11 (G/ U)AG-repeat segment in the trp leader transcript. To promote termination, TRAP must bind to the nascent RNA before the antiterminator structure forms. Because only 20 nucleotides sep- arate the TRAP-binding site from the 3' end of the antiterminator, TRAP has a short time frame to control this regulatory decision. Synchronization of factor binding and/or RNA folding with the RNA polymerase position is a major challenge in all attenuation mechanisms.