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-Structure paper
タイトル | Structures of the human Mediator and Mediator-bound preinitiation complex. |
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ジャーナル・号・ページ | Science, Vol. 372, Issue 6546, Year 2021 |
掲載日 | 2021年6月4日 |
著者 | Xizi Chen / Xiaotong Yin / Jiabei Li / Zihan Wu / Yilun Qi / Xinxin Wang / Weida Liu / Yanhui Xu / |
PubMed 要旨 | The 1.3-megadalton transcription factor IID (TFIID) is required for preinitiation complex (PIC) assembly and RNA polymerase II (Pol II)-mediated transcription initiation on almost all genes. The 26- ...The 1.3-megadalton transcription factor IID (TFIID) is required for preinitiation complex (PIC) assembly and RNA polymerase II (Pol II)-mediated transcription initiation on almost all genes. The 26-subunit Mediator stimulates transcription and cyclin-dependent kinase 7 (CDK7)-mediated phosphorylation of the Pol II C-terminal domain (CTD). We determined the structures of human Mediator in the Tail module-extended (at near-atomic resolution) and Tail-bent conformations and structures of TFIID-based PIC-Mediator (76 polypeptides, ~4.1 megadaltons) in four distinct conformations. PIC-Mediator assembly induces concerted reorganization (Head-tilting and Middle-down) of Mediator and creates a Head-Middle sandwich, which stabilizes two CTD segments and brings CTD to CDK7 for phosphorylation; this suggests a CTD-gating mechanism favorable for phosphorylation. The TFIID-based PIC architecture modulates Mediator organization and TFIIH stabilization, underscoring the importance of TFIID in orchestrating PIC-Mediator assembly. |
リンク | Science / PubMed:33958484 |
手法 | EM (単粒子) |
解像度 | 2.8 - 7.1 Å |
構造データ | EMDB-31191, PDB-7emf: EMDB-31192: EMDB-31193: EMDB-31194: EMDB-31195: EMDB-31196: EMDB-31204, PDB-7ena: EMDB-31205: EMDB-31206: EMDB-31207, PDB-7enc: EMDB-31208: Local maps of TFIID-based PIC-Mediator complex (deletion of MED1-IDR) EMDB-31211, PDB-7enj: EMDB-31212: EMDB-31213: EMDB-31214: EMDB-31215: |
化合物 | ChemComp-ZN: ChemComp-MG: ChemComp-SF4: |
由来 |
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キーワード | TRANSCRIPTION (転写 (生物学)) / Mediator complex / mediator / preinitiation complex / transcription initiation (転写 (生物学)) |