3JCM

Cryo-EM structure of the spliceosomal U4/U6.U5 tri-snRNP

3JCM の概要

• エントリーDOI: 10.2210/pdb3jcm/pdb
• EMDBエントリー: 6561
• 分子名称: Pre-mRNA-splicing factor 8, Small nuclear ribonucleoprotein Sm D3, Small nuclear ribonucleoprotein-associated protein B, ... (29 entities in total)
• 機能のキーワード: u4/u6.u5 tri-snrnp, pre-mrna, transcription
• 由来する生物種: Saccharomyces cerevisiae S288c; 詳細
• タンパク質・核酸の鎖数: 34
• 化学式量合計: 1373832.70

構造登録者

Wan, R.,Yan, C.,Bai, R.,Wang, L.,Huang, M.,Wong, C.C.,Shi, Y. (登録日: 2015-12-23, 公開日: 2016-02-24, 最終更新日: 2024-03-20)

主引用文献

Wan, R.,Yan, C.,Bai, R.,Wang, L.,Huang, M.,Wong, C.C.,Shi, Y.
The 3.8 angstrom structure of the U4/U6.U5 tri-snRNP: Insights into spliceosome assembly and catalysis
Science, 351:466-475, 2016

PubMed Abstract: Splicing of precursor messenger RNA is accomplished by a dynamic megacomplex known as the spliceosome. Assembly of a functional spliceosome requires a preassembled U4/U6.U5 tri-snRNP complex, which comprises the U5 small nuclear ribonucleoprotein (snRNP), the U4 and U6 small nuclear RNA (snRNA) duplex, and a number of protein factors. Here we report the three-dimensional structure of a Saccharomyces cerevisiae U4/U6.U5 tri-snRNP at an overall resolution of 3.8 angstroms by single-particle electron cryomicroscopy. The local resolution for the core regions of the tri-snRNP reaches 3.0 to 3.5 angstroms, allowing construction of a refined atomic model. Our structure contains U5 snRNA, the extensively base-paired U4/U6 snRNA, and 30 proteins including Prp8 and Snu114, which amount to 8495 amino acids and 263 nucleotides with a combined molecular mass of ~1 megadalton. The catalytic nucleotide U80 from U6 snRNA exists in an inactive conformation, stabilized by its base-pairing interactions with U4 snRNA and protected by Prp3. Pre-messenger RNA is bound in the tri-snRNP through base-pairing interactions with U6 snRNA and loop I of U5 snRNA. This structure, together with that of the spliceosome, reveals the molecular choreography of the snRNAs in the activation process of the spliceosomal ribozyme.

PubMed: 26743623
DOI: 10.1126/science.aad6466

実験手法

ELECTRON MICROSCOPY (3.8 Å)