title: The initiation factor TFE and the elongation factor Spt4/5 compete for the RNAP clamp during transcription initiation and elongation.
abstract: TFIIE and the archaeal homolog TFE enhance DNA strand separation of eukaryotic RNAPII and the archaeal RNAP during transcription initiation by an unknown mechanism. We have developed a fluorescently labeled recombinant M. jannaschii RNAP system to probe the archaeal transcription initiation complex, consisting of promoter DNA, TBP, TFB, TFE, and RNAP. We have localized the position of the TFE winged helix (WH) and Zinc ribbon (ZR) domains on the RNAP using single-molecule FRET. The interaction sites of the TFE WH domain and the transcription elongation factor Spt4/5 overlap, and both factors compete for RNAP binding. Binding of Spt4/5 to RNAP represses promoter-directed transcription in the absence of TFE, which alleviates this effect by displacing Spt4/5 from RNAP. During elongation, Spt4/5 can displace TFE from the RNAP elongation complex and stimulate processivity. Our results identify the RNAP "clamp" region as a regulatory hot spot for both transcription initiation and transcription elongation.
authors.affiliation: University College London, Institute for Structural and Molecular Biology, Division of Biosciences, Darwin Building, Gower Street, London WC1E 6BT, UK.
authors.forename: Dina
authors.initials: D
authors.lastname: Grohmann
authors.forename: Julia
authors.initials: J
authors.lastname: Nagy
authors.forename: Anirban
authors.initials: A
authors.lastname: Chakraborty
authors.forename: Daniel
authors.initials: D
authors.lastname: Klose
authors.forename: Daniel
authors.initials: D
authors.lastname: Fielden
authors.forename: Richard H
authors.initials: RH
authors.lastname: Ebright
authors.forename: Jens
authors.initials: J
authors.lastname: Michaelis
authors.forename: Finn
authors.initials: F
authors.lastname: Werner
mesh_terms: D000595:Amino Acid Sequence; D001105:Archaea / Q000235:genetics / Q000378:metabolism; D019843:Archaeal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D048229:Sulfolobus solfataricus / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D002868:Chromosomal Proteins, Non-Histone; D035602:Transcriptional Elongation Factors; C069940:SPT5 transcriptional elongation factor; D012321:DNA-Directed RNA Polymerases