5LJ3

Structure of the core of the yeast spliceosome immediately after branching

5LJ3 の概要

• エントリーDOI: 10.2210/pdb5lj3/pdb
• EMDBエントリー: 4055
• 分子名称: U5 snRNA (small nuclear RNA), ISY1, CWC22, ... (34 entities in total)
• 機能のキーワード: spliceosome, snrnp, pre-mrna splicing, trans-esterification, lariat intermediate, complex c, splicing
• 由来する生物種: Saccharomyces cerevisiae; 詳細
• タンパク質・核酸の鎖数: 38
• 化学式量合計: 1755830.27

構造登録者

Galej, W.P.,Wilkinson, M.F.,Fica, S.M.,Oubridge, C.,Newman, A.J.,Nagai, K. (登録日: 2016-07-17, 公開日: 2016-08-03, 最終更新日: 2024-10-23)

主引用文献

Galej, W.P.,Wilkinson, M.E.,Fica, S.M.,Oubridge, C.,Newman, A.J.,Nagai, K.
Cryo-EM structure of the spliceosome immediately after branching.
Nature, 537:197-201, 2016

PubMed Abstract: Precursor mRNA (pre-mRNA) splicing proceeds by two consecutive transesterification reactions via a lariat-intron intermediate. Here we present the 3.8 Å cryo-electron microscopy structure of the spliceosome immediately after lariat formation. The 5'-splice site is cleaved but remains close to the catalytic Mg site in the U2/U6 small nuclear RNA (snRNA) triplex, and the 5'-phosphate of the intron nucleotide G(+1) is linked to the branch adenosine 2'OH. The 5'-exon is held between the Prp8 amino-terminal and linker domains, and base-pairs with U5 snRNA loop 1. Non-Watson-Crick interactions between the branch helix and 5'-splice site dock the branch adenosine into the active site, while intron nucleotides +3 to +6 base-pair with the U6 snRNA ACAGAGA sequence. Isy1 and the step-one factors Yju2 and Cwc25 stabilize docking of the branch helix. The intron downstream of the branch site emerges between the Prp8 reverse transcriptase and linker domains and extends towards the Prp16 helicase, suggesting a plausible mechanism of remodelling before exon ligation.

PubMed: 27459055
DOI: 10.1038/nature19316

実験手法

ELECTRON MICROSCOPY (3.8 Å)