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CryoEM structure of Yeast TFIIK (Kin28/Ccl1/Tfb3) ComplexCryoEM structure of Yeast TFIIK (Kin28/Ccl1/Tfb3) Complex
Structural highlights
FunctionCCL1_YEAST Regulatory component of the TFIIK complex (KIN28-CCL1 dimer) which is the protein kinase component of transcription factor IIH (TFIIH) and phosphorylates the C-terminal domain of RNA polymerase II during transition from transcription to elongation after preinitiation complex (PIC) formation, thereby positively regulating transcription. TFIIH (or factor B) is essential for both basal and activated transcription, and is involved in nucleotide excision repair (NER) of damaged DNA. TFIIH has DNA-dependent ATPase activity and is essential for polymerase II transcription in vitro. Publication Abstract from PubMedDuring transcription initiation, the general transcription factor TFIIH marks RNA polymerase II by phosphorylating Ser5 of the carboxyl-terminal domain (CTD) of Rpb1, which is followed by extensive modifications coupled to transcription elongation, mRNA processing, and histone dynamics. We have determined a 3.5-A resolution cryo-electron microscopy (cryo-EM) structure of the TFIIH kinase module (TFIIK in yeast), which is composed of Kin28, Ccl1, and Tfb3, yeast homologs of CDK7, cyclin H, and MAT1, respectively. The carboxyl-terminal region of Tfb3 was lying at the edge of catalytic cleft of Kin28, where a conserved Tfb3 helix served to stabilize the activation loop in its active conformation. By combining the structure of TFIIK with the previous cryo-EM structure of the preinitiation complex, we extend the previously proposed model of the CTD path to the active site of TFIIK. Structure of TFIIK for phosphorylation of CTD of RNA polymerase II.,van Eeuwen T, Li T, Kim HJ, Gorbea Colon JJ, Parker MI, Dunbrack RL, Garcia BA, Tsai KL, Murakami K Sci Adv. 2021 Apr 7;7(15):eabd4420. doi: 10.1126/sciadv.abd4420. Print 2021 Apr. PMID:33827808[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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