6QX9

Structure of a human fully-assembled precatalytic spliceosome (pre-B complex).

これはPDB形式変換不可エントリーです。

6QX9 の概要

• エントリーDOI: 10.2210/pdb6qx9/pdb
• 関連するPDBエントリー: 6QW6
• EMDBエントリー: 4658 4665
• 分子名称: U1 snRNA, U4/U6 small nuclear ribonucleoprotein Prp31, Small nuclear ribonucleoprotein Sm D1, ... (54 entities in total)
• 機能のキーワード: rnp complex, splicing, rna, protein, spliceosome
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 71
• 化学式量合計: 2871622.27

構造登録者

Charenton, C.,Wilkinson, M.E.,Nagai, K. (登録日: 2019-03-07, 公開日: 2019-04-17, 最終更新日: 2024-11-13)

主引用文献

Charenton, C.,Wilkinson, M.E.,Nagai, K.
Mechanism of 5' splice site transfer for human spliceosome activation.
Science, 364:362-367, 2019

PubMed Abstract: The prespliceosome, comprising U1 and U2 small nuclear ribonucleoproteins (snRNPs) bound to the precursor messenger RNA 5' splice site (5'SS) and branch point sequence, associates with the U4/U6.U5 tri-snRNP to form the fully assembled precatalytic pre-B spliceosome. Here, we report cryo-electron microscopy structures of the human pre-B complex captured before U1 snRNP dissociation at 3.3-angstrom core resolution and the human tri-snRNP at 2.9-angstrom resolution. U1 snRNP inserts the 5'SS-U1 snRNA helix between the two RecA domains of the Prp28 DEAD-box helicase. Adenosine 5'-triphosphate-dependent closure of the Prp28 RecA domains releases the 5'SS to pair with the nearby U6 ACAGAGA-box sequence presented as a mobile loop. The structures suggest that formation of the 5'SS-ACAGAGA helix triggers remodeling of an intricate protein-RNA network to induce Brr2 helicase relocation to its loading sequence in U4 snRNA, enabling Brr2 to unwind the U4/U6 snRNA duplex to allow U6 snRNA to form the catalytic center of the spliceosome.

PubMed: 30975767
DOI: 10.1126/science.aax3289

実験手法

ELECTRON MICROSCOPY (3.28 Å)