title: RNA polymerase III subunit architecture and implications for open promoter complex formation.
abstract: Transcription initiation by eukaryotic RNA polymerase (Pol) III relies on the TFIIE-related subcomplex C82/34/31. Here we combine cross-linking and hydroxyl radical probing to position the C82/34/31 subcomplex around the Pol III active center cleft. The extended winged helix (WH) domains 1 and 4 of C82 localize to the polymerase domains clamp head and clamp core, respectively, and the two WH domains of C34 span the polymerase cleft from the coiled-coil region of the clamp to the protrusion. The WH domains of C82 and C34 apparently cooperate with other mobile regions flanking the cleft during promoter DNA binding, opening, and loading. Together with published data, our results complete the subunit architecture of Pol III and indicate that all TFIIE-related components of eukaryotic and archaeal transcription systems adopt an evolutionarily conserved location in the upper part of the cleft that supports their functions in open promoter complex formation and stabilization.
authors.affiliation: Institute of Molecular Biology,  Academia Sinica, Taipei,  Taiwan 115, Republic of China.
authors.forename: Chih-Chien
authors.initials: CC
authors.lastname: Wu
authors.forename: Franz
authors.initials: F
authors.lastname: Herzog
authors.forename: Stefan
authors.initials: S
authors.lastname: Jennebach
authors.forename: Yu-Chun
authors.initials: YC
authors.lastname: Lin
authors.forename: Chih-Yu
authors.initials: CY
authors.lastname: Pai
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
authors.forename: Patrick
authors.initials: P
authors.lastname: Cramer
authors.forename: Hung-Ta
authors.initials: HT
authors.lastname: Chen
mesh_terms: D020134:Catalytic Domain; D003432:Cross-Linking Reagents / Q000494:pharmacology; D008027:Light; D008239:Lysine / Q000378:metabolism; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding / Q000187:drug effects / Q000528:radiation effects; D060066:Protein Interaction Maps / Q000187:drug effects / Q000528:radiation effects; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D021122:Protein Subunits / Q000737:chemistry* / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects / Q000528:radiation effects; D012320:RNA Polymerase III / Q000737:chemistry* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D013329:Structure-Activity Relationship
chemical_list: D003432:Cross-Linking Reagents; D021122:Protein Subunits; D012320:RNA Polymerase III; D008239:Lysine