9N7B

SSU processome maturation and disassembly, State O

これはPDB形式変換不可エントリーです。

9N7B の概要

• エントリーDOI: 10.2210/pdb9n7b/pdb
• EMDBエントリー: 49058 49091
• 分子名称: 18S rRNA, 40S ribosomal protein S16-A, 40S ribosomal protein S11-A, ... (39 entities in total)
• 機能のキーワード: ssu processome, ribosome assembly, rna folding, rna-protein interactions, ribosome
• 由来する生物種: Saccharomyces cerevisiae S288C; 詳細
• タンパク質・核酸の鎖数: 37
• 化学式量合計: 1993706.86

構造登録者

Buzovetsky, O.,Klinge, S. (登録日: 2025-02-05, 公開日: 2025-10-29, 最終更新日: 2025-12-31)

主引用文献

Buzovetsky, O.,Klinge, S.
Helicase-mediated mechanism of SSU processome maturation and disassembly.
Nature, 648:746-754, 2025

PubMed Abstract: Eukaryotic ribosomal small subunit (SSU) assembly requires the SSU processome, a nucleolar precursor containing the RNA chaperone U3 small nucleolar RNA (snoRNA). The underlying molecular mechanisms of SSU processome maturation, remodelling, disassembly and RNA quality control, and the transitions between states remain unknown owing to a paucity of intermediates. Here we report 16 native SSU processome structures alongside genetic data, revealing how two helicases, the Mtr4-exosome and Dhr1, are controlled for accurate and unidirectional ribosome biogenesis. Our data show how irreversible pre-ribosomal RNA degradation by the redundantly tethered RNA exosome couples the transformation of the SSU processome into a pre-40S particle, during which Utp14 can probe evolving surfaces, ultimately positioning and activating Dhr1 to unwind the U3 snoRNA and initiate nucleolar pre-40S release. This study highlights a paradigm for large dynamic RNA-protein complexes in which irreversible RNA degradation drives compositional changes and communicates these changes to govern enzyme activity while maintaining overall quality control.

PubMed: 41162712
DOI: 10.1038/s41586-025-09688-3

実験手法

ELECTRON MICROSCOPY (3.25 Å)