title: TRAP binding to the Bacillus subtilis trp leader region RNA causes efficient transcription termination at a weak intrinsic terminator.
abstract: The Bacillus subtilis trpEDCFBA operon is regulated by a transcription attenuation mechanism controlled by the trp RNA-binding attenuation protein (TRAP). TRAP binds to 11 (G/U)AG repeats in the trp leader transcript and prevents formation of an antiterminator, which allows formation of an intrinsic terminator (attenuator). Previously, formation of the attenuator RNA structure was believed to be solely responsible for signaling RNA polymerase (RNAP) to halt transcription. However, base substitutions that prevent formation of the antiterminator, and thus allow the attenuator structure to form constitutively, do not result in efficient transcription termination. The observation that the attenuator requires the presence of TRAP bound to the nascent RNA to cause efficient transcription termination suggests TRAP has an additional role in causing termination at the attenuator. We show that the trp attenuator is a weak intrinsic terminator due to low GC content of the hairpin stem and interruptions in the U-stretch following the hairpin. We also provide evidence that termination at the trp attenuator requires forward translocation of RNA polymerase and that TRAP binding to the nascent transcript can induce this activity.
authors.affiliation: Department of Biological Sciences, University at Buffalo, the State University of New York, Buffalo, New York 14260, USA.
authors.forename: Kristine D
authors.initials: KD
authors.lastname: Potter
authors.forename: Natalie M
authors.initials: NM
authors.lastname: Merlino
authors.forename: Timothy
authors.initials: T
authors.lastname: Jacobs
authors.forename: Paul
authors.initials: P
authors.lastname: Gollnick
mesh_terms: D020121:5' Untranslated Regions; D001412:Bacillus subtilis / Q000235:genetics*; D001426:Bacterial Proteins / Q000378:metabolism*; D001482:Base Composition; D001665:Binding Sites; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors; D009841:Oligonucleotides / Q000737:chemistry; D009876:Operon; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014364:Tryptophan / Q000378:metabolism
chemical_list: D020121:5' Untranslated Regions; D001426:Bacterial Proteins; C079092:MtrB protein, Bacteria; D009841:Oligonucleotides; D012329:RNA, Bacterial; D016601:RNA-Binding Proteins; D038621:Regulatory Sequences, Ribonucleic Acid; D014157:Transcription Factors; D014364:Tryptophan; D012321:DNA-Directed RNA Polymerases