9FSO

Human RNA Polymerase III Class III Open Pre-initiation Complex 1 (OC1)

9FSO の概要

• エントリーDOI: 10.2210/pdb9fso/pdb
• EMDBエントリー: 50730
• 分子名称: DNA-directed RNA polymerase III subunit RPC1, DNA-directed RNA polymerase III subunit RPC10, DNA-directed RNA polymerases I and III subunit RPAC1, ... (28 entities in total)
• 機能のキーワード: rna polymerase, snapc, tfiiib, snrna, pre-initiation complex, u6_2, transcription
• 由来する生物種: Homo sapiens (human); 詳細
• タンパク質・核酸の鎖数: 25
• 化学式量合計: 1143981.51

構造登録者

Shah, S.Z.,Ramsay, E.P.,Cecatiello, V.,Perry, T.N.,Vannini, A. (登録日: 2024-06-21, 公開日: 2025-01-15)

主引用文献

Shah, S.Z.,Perry, T.N.,Graziadei, A.,Cecatiello, V.,Kaliyappan, T.,Misiaszek, A.D.,Muller, C.W.,Ramsay, E.P.,Vannini, A.
Structural insights into distinct mechanisms of RNA polymerase II and III recruitment to snRNA promoters.
Nat Commun, 16:141-141, 2025

PubMed Abstract: RNA polymerase III (Pol III) transcribes short, essential RNAs, including the U6 small nuclear RNA (snRNA). At U6 snRNA genes, Pol III is recruited by the snRNA Activating Protein Complex (SNAPc) and a Brf2-containing TFIIIB complex, forming a pre-initiation complex (PIC). Uniquely, SNAPc also recruits Pol II at the remaining splicesosomal snRNA genes (U1, 2, 4 and 5). The mechanism of SNAPc cross-polymerase engagement and the role of the SNAPC2 and SNAPC5 subunits remain poorly defined. Here, we present cryo-EM structures of the full-length SNAPc-containing Pol III PIC assembled on the U6 snRNA promoter in the open and melting states at 3.2-4.2 Å resolution. The structural comparison revealed differences with the Saccharomyces cerevisiae Pol III PIC and the basis of selective SNAPc engagement within Pol III and Pol II PICs. Additionally, crosslinking mass spectrometry localizes SNAPC2 and SNAPC5 near the promoter DNA, expanding upon existing descriptions of snRNA Pol III PIC structure.

PubMed: 39747245
DOI: 10.1038/s41467-024-55553-8

実験手法

ELECTRON MICROSCOPY (3.28 Å)