title: The transcriptional regulator RfaH stimulates RNA chain synthesis after recruitment to elongation complexes by the exposed nontemplate DNA strand.
abstract: The transcriptional regulatory protein RfaH controls expression of several operons that encode extracytoplasmic components in bacteria. Regulation by RfaH occurs during transcript elongation and depends on a 5'-proximal, transcribed nucleic acid sequence called ops that induces transcriptional pausing in vitro and in vivo. We report that RfaH recognizes RNA polymerase transcribing RfaH-regulated operons by interacting with the ops sequence in the exposed nontemplate DNA strand of ops-paused transcription complexes. Although RfaH delays escape from the ops pause, once escape occurs, RfaH enhances elongation by suppressing pausing and rho-dependent termination without apparent involvement of other accessory proteins. This activity predicts a cumulative antitermination model for RfaH's regulation of ops-containing operons in vivo.
authors: Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA.
authors: Irina
authors: I
authors: Artsimovitch
authors: Robert
authors: R
authors: Landick
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D019143:Evolution, Molecular; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D010441:Peptide Chain Elongation, Translational / Q000235:genetics*; D010445:Peptide Elongation Factors / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D012329:RNA, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D013698:Templates, Genetic; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D010445:Peptide Elongation Factors; D012329:RNA, Bacterial; C106401:RfaH protein, E coli; D015534:Trans-Activators