Does TRAP binding to nascent trp leader RNA influence transcription attenuation beyond its effects on RNA structure?
K. Pierce*. 1) Department of Biological Sciences, State University of New York at Buffalo, NY, USA. TRAP (trp RNA-binding Attenuation Protein) regulates expression of the Bacillus subtilis trpEDCFBA operon, which encodes enzymes for tryptophan biosynthesis, by transcription attenuation and translational control mechanisms. During transcription in the absence of tryptophan, the nascent trp leader RNA assumes an anti-terminator structure and transcription continues into the coding region allowing expression of the trp genes; thus more tryptophan to be synthesized. In the presence of tryptophan the 11-subunit TRAP protein binds to 11 (G/U)AG repeats in the 5’-untranslated leader region of trp mRNA. In this case the trp leader RNA assumes a transcription termination secondary structure, which blocks transcription elongation into the coding region. In addition to its role in altering the nascent RNA secondary structure it is possible that TRAP has an additional role in regulating transcript
