7ml4
RNA polymerase II initially transcribing complex (ITC)
Structural highlights
FunctionT2FA_YEAST TFIIF is a general transcription initiation factor that binds to RNA polymerase II. Its functions include the recruitment of RNA polymerase II to the promoter bound DNA-TBP-TFIIB complex, decreasing the affinity of RNA polymerase II for non-specific DNA, allowing for the subsequent recruitment of TFIIE and TFIIH, and facilitating RNA polymerase II elongation.[1] Publication Abstract from PubMedPrevious structural studies of the initiation-elongation transition of RNA polymerase II (pol II) transcription have relied on the use of synthetic oligonucleotides, often artificially discontinuous to capture pol II in the initiating state. Here, we report multiple structures of initiation complexes converted de novo from a 33-subunit yeast pre-initiation complex (PIC) through catalytic activities and subsequently stalled at different template positions. We determine that PICs in the initially transcribing complex (ITC) can synthesize a transcript of approximately 26 nucleotides before transitioning to an elongation complex (EC) as determined by the loss of general transcription factors (GTFs). Unexpectedly, transition to an EC was greatly accelerated when an ITC encountered a downstream EC stalled at promoter proximal regions and resulted in a collided head-to-end dimeric EC complex. Our structural analysis reveals a dynamic state of TFIIH, the largest of GTFs, in PIC/ITC with distinct functional consequences at multiple steps on the pathway to elongation. Structural visualization of de novo transcription initiation by Saccharomyces cerevisiae RNA polymerase II.,Yang C, Fujiwara R, Kim HJ, Basnet P, Zhu Y, Gorbea Colon JJ, Steimle S, Garcia BA, Kaplan CD, Murakami K Mol Cell. 2022 Feb 3;82(3):660-676.e9. doi: 10.1016/j.molcel.2021.12.020. Epub , 2022 Jan 19. PMID:35051353[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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