title: NusA interaction with the α subunit of E. coli RNA polymerase is via the UP element site and releases autoinhibition.
abstract: Elongating Escherichia coli RNAP is modulated by NusA protein. The C-terminal domain (CTD) of the RNAP α subunit (αCTD) interacts with the acidic CTD 2 (AR2) of NusA, releasing the autoinhibitory blockade of the NusA S1-KH1-KH2 motif and allowing NusA to bind nascent nut spacer RNA. We determined the solution conformation of the AR2:αCTD complex. The αCTD residues that interface with AR2 are identical to those that recognize UP promoter elements A nusA-ΔAR2 mutation does not affect UP-dependent rrnH transcription initiation in vivo. Instead, the mutation inhibits Rho-dependent transcription termination at phage λtR1, which lies adjacent to the λnutR sequence. The Rho-dependent λtimm terminator, which is not preceded by a λnut sequence, is fully functional. We propose that constitutive binding of NusA-ΔAR2 to λnutR occludes Rho. In addition, the mutation confers a dominant defect in exiting stationary phase.
authors: Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
authors: Kristian
authors: K
authors: Schweimer
authors: Stefan
authors: S
authors: Prasch
authors: Pagadala Santhanam
authors: PS
authors: Sujatha
authors: Mikhail
authors: M
authors: Bubunenko
authors: Max E
authors: ME
authors: Gottesman
authors: Paul
authors: P
authors: Rösch
mesh_terms: D001665:Binding Sites / Q000235:genetics; D003001:Cloning, Molecular; D003460:Crystallization; D018360:Crystallography, X-Ray; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009154:Mutation; D010445:Peptide Elongation Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012234:Rho Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors; D014162:Transfection; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; C119762:NutR protein, bacteriophage lambda; D010445:Peptide Elongation Factors; D011993:Recombinant Fusion Proteins; D012234:Rho Factor; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D014764:Viral Proteins; C068727:nusA protein, E coli; D012313:RNA; D012321:DNA-Directed RNA Polymerases; C113275:RNA polymerase alpha subunit