Association of the winged helix motif of the TFIIE alpha subunit of TFIIE with either the TFIIE beta subunit or TFIIB distinguishes its functions in transcription

作者：Tanaka Aki; Akimoto Yusuke; Kobayashi Satoko; Hisatake Koji; Hanaoka Fumio; Ohkuma Yoshiaki^*

来源：Genes to Cells, 2015, 20(3): 203-216.

DOI：10.1111/gtc.12212

In eukaryotes, the general transcription factor TFIIE consists of two subunits, and , and plays essential roles in transcription. Structure-function studies indicate that TFIIE has three-winged helix (WH) motifs, with one in TFIIE and two in TFIIE. Recent studies suggested that, by binding to the clamp region of RNA polymerase II, TFIIE-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 TFIIE-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 TFIIE and the latter class was defective in binding to the N-terminal cyclin homology region of TFIIB. Furthermore, TFIIE-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.

• 出版日期2015-3