9V7O

Cryo-EM structures of the Azoarcus pre-tRNA(ILE) conformation b undergoing the first-step self-splicing

9V7O の概要

• エントリーDOI: 10.2210/pdb9v7o/pdb
• EMDBエントリー: 64819
• 分子名称: RNA (284-MER), GUANOSINE, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: azoarcus pre-trna(ile), self-splicing, pre-1s, rna structure, rna
• 由来する生物種: Azoarcus olearius
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 276013.52

構造登録者

Hong, Y.,Liu, J.,Zhang, X.,Liu, J.,Li, S.,Zhang, K. (登録日: 2025-05-28, 公開日: 2026-03-25, 最終更新日: 2026-04-08)

主引用文献

Hong, Y.,Liu, J.,Zhang, X.,Liu, J.,Li, S.,Zhang, K.
Pre-splicing conformation and stepwise circularization of a group I intron in Azoarcus pre-tRNA.
Nat Commun, 2026

PubMed Abstract: Group I introns are catalytic RNAs capable of self-splicing, yet structural insights into full-length precursor RNAs and post-splicing circularization have been limited. Here, we present cryo-EM structures of the Azoarcus pre-tRNA system across key catalytic stages, including the full-length precursor in Pre-1S conformations, the linear intron, and the circular introns, at 2.8-3.3 Å resolution. These structures reveal a preformed P1 helix, register shifts during splicing, and a conformational flip of G37 that stabilizes the circularization site. Biochemical analyses confirm a two-step circularization mechanism, generating a secondary circular product via an alternative ligation site. Together, our results provide an atomic-level view of a group I intron system through splicing and circularization. This work uncovers structural principles governing RNA conformational dynamics, catalysis, and circular RNA formation, with broad implications for ribozyme engineering.

PubMed: 41862486
DOI: 10.1038/s41467-026-70747-y

実験手法

ELECTRON MICROSCOPY (3.06 Å)