title: Association of the winged helix motif of the TFIIEα subunit of TFIIE with either the TFIIEβ subunit or TFIIB distinguishes its functions in transcription.
abstract: In eukaryotes, the general transcription factor TFIIE consists of two subunits, α and β, and plays essential roles in transcription. Structure-function studies indicate that TFIIE has three-winged helix (WH) motifs, with one in TFIIEα and two in TFIIEβ. Recent studies suggested that, by binding to the clamp region of RNA polymerase II, TFIIEα-WH promotes the conformational change that transforms the promoter-bound inactive preinitiation complex to the active complex. Here, to elucidate its roles in transcription, functional analyses of point-mutated human TFIIEα-WH proteins were carried out. In vitro transcription analyses identified two classes of mutants. One class was defective in transcription initiation, and the other was defective in the transition from initiation to elongation. Analyses of the binding of this motif to other general transcription factors showed that the former class was defective in binding to the basic helix-loop-helix motif of TFIIEβ and the latter class was defective in binding to the N-terminal cyclin homology region of TFIIB. Furthermore, TFIIEα-WH bound to the TFIIH XPB subunit at a third distinct region. Therefore, these results provide further insights into the mechanisms underlying RNA polymerase II activation at the initial stages of transcription.
authors.affiliation: Laboratory of Gene Regulation, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Tanaka
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Akimoto
authors.forename: Satoko
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Koji
authors.initials: K
authors.lastname: Hisatake
authors.forename: Fumio
authors.initials: F
authors.lastname: Hanaoka
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ohkuma
mesh_terms: D000818:Animals; D016466:CHO Cells; D017173:Caenorhabditis elegans; D003412:Cricetulus; D004331:Drosophila melanogaster; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D009154:Mutation; D012441:Saccharomyces cerevisiae; D012568:Schizosaccharomyces; D048229:Sulfolobus solfataricus; D061805:Transcription Elongation, Genetic; D035581:Transcription Factor TFIIB / Q000378:metabolism*; D051758:Transcription Factor TFIIH / Q000378:metabolism; D019473:Transcription Factors, TFII / Q000378:metabolism*; D061785:Transcription Initiation, Genetic; D051540:Winged-Helix Transcription Factors / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D035581:Transcription Factor TFIIB; D019473:Transcription Factors, TFII; D051540:Winged-Helix Transcription Factors; C066644:transcription factor TFIIE; D051758:Transcription Factor TFIIH