title: An α helix to β barrel domain switch transforms the transcription factor RfaH into a translation factor.
abstract: NusG homologs regulate transcription and coupled processes in all living organisms. The Escherichia coli (E. coli) two-domain paralogs NusG and RfaH have conformationally identical N-terminal domains (NTDs) but dramatically different carboxy-terminal domains (CTDs), a β barrel in NusG and an α hairpin in RfaH. Both NTDs interact with elongating RNA polymerase (RNAP) to reduce pausing. In NusG, NTD and CTD are completely independent, and NusG-CTD interacts with termination factor Rho or ribosomal protein S10. In contrast, RfaH-CTD makes extensive contacts with RfaH-NTD to mask an RNAP-binding site therein. Upon RfaH interaction with its DNA target, the operon polarity suppressor (ops) DNA, RfaH-CTD is released, allowing RfaH-NTD to bind to RNAP. Here, we show that the released RfaH-CTD completely refolds from an all-α to an all-β conformation identical to that of NusG-CTD. As a consequence, RfaH-CTD binding to S10 is enabled and translation of RfaH-controlled operons is strongly potentiated. PAPERFLICK:
authors: Lehrstuhl Biopolymere und Forschungszentrum für Bio-Makromoleküle, Universität Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany.
authors: Björn M
authors: BM
authors: Burmann
authors: Stefan H
authors: SH
authors: Knauer
authors: Anastasia
authors: A
authors: Sevostyanova
authors: Kristian
authors: K
authors: Schweimer
authors: Rachel A
authors: RA
authors: Mooney
authors: Robert
authors: R
authors: Landick
authors: Irina
authors: I
authors: Artsimovitch
authors: Paul
authors: P
authors: Rösch
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000737:chemistry / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009876:Operon; D010445:Peptide Elongation Factors / Q000737:chemistry* / Q000378:metabolism*; D014176:Protein Biosynthesis; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012269:Ribosomal Proteins / Q000378:metabolism; D016415:Sequence Alignment; D015534:Trans-Activators / Q000737:chemistry* / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; C070291:NusG protein, E coli; D010445:Peptide Elongation Factors; C106401:RfaH protein, E coli; D012269:Ribosomal Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C029537:ribosomal protein S10