7egb
TFIID-based holo PIC on SCP promoter
Structural highlights
FunctionMAT1_HUMAN Stabilizes the cyclin H-CDK7 complex to form a functional CDK-activating kinase (CAK) enzymatic complex. CAK activates the cyclin-associated kinases CDK1, CDK2, CDK4 and CDK6 by threonine phosphorylation. CAK complexed to the core-TFIIH basal transcription factor activates RNA polymerase II by serine phosphorylation of the repetitive C-terminus domain (CTD) of its large subunit (POLR2A), allowing its escape from the promoter and elongation of the transcripts. Involved in cell cycle control and in RNA transcription by RNA polymerase II.[1] Publication Abstract from PubMedTranscription factor IID (TFIID) recognizes core promoters and supports preinitiation complex (PIC) assembly for RNA polymerase II (Pol II)-mediated eukaryotic transcription. We determined the structures of human TFIID-based PIC in three stepwise assembly states and revealed two-track PIC assembly: stepwise promoter deposition to Pol II and extensive modular reorganization on track I (on TATA-TFIID-binding element promoters) versus direct promoter deposition on track II (on TATA-only and TATA-less promoters). The two tracks converge at an ~50-subunit holo PIC in identical conformation, whereby TFIID stabilizes PIC organization and supports loading of cyclin-dependent kinase (CDK)-activating kinase (CAK) onto Pol II and CAK-mediated phosphorylation of the Pol II carboxyl-terminal domain. Unexpectedly, TBP of TFIID similarly bends TATA box and TATA-less promoters in PIC. Our study provides structural visualization of stepwise PIC assembly on highly diversified promoters. Structural insights into preinitiation complex assembly on core promoters.,Chen X, Qi Y, Wu Z, Wang X, Li J, Zhao D, Hou H, Li Y, Yu Z, Liu W, Wang M, Ren Y, Li Z, Yang H, Xu Y Science. 2021 Apr 30;372(6541):eaba8490. doi: 10.1126/science.aba8490. Epub 2021 , Apr 1. PMID:33795473[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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