22AV

Cryo-EM structure of NSUN2-tRNATyr-SAM

22AV の概要

• エントリーDOI: 10.2210/pdb22av/pdb
• EMDBエントリー: 68138
• 分子名称: NSUN2, tRNAtyr (78-MER), S-ADENOSYLMETHIONINE (3 entities in total)
• 機能のキーワード: trna, m5c rna methyltransferase, nsun2, transferase/rna, transferase-rna complex
• 由来する生物種: Homo sapiens; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 112158.07

構造登録者

Hu, Q.,Yang, W.,Li, S.,Zhang, K. (登録日: 2026-01-05, 公開日: 2026-06-24)

主引用文献

Hu, Q.,Yang, W.,Yu, Y.,Yi, R.,Zhang, Y.,Duan, L.,Li, F.,Zhang, K.,Gong, Q.,Li, S.
Structure-driven RNA remodeling underlies broad substrate recognition by NSUN2.
Sci China Life Sci, 2026

PubMed Abstract: The human RNA mC methyltransferase NSUN2 catalyzes site-specific cytosine methylation across diverse RNA substrates and thereby regulates a wide range of biological and physiological processes. However, the molecular basis by which NSUN2 achieves broad substrate recognition while maintaining catalytic specificity has remained unclear. Here, we determine structures of human NSUN2 in both substrate-free and substrate-bound states using X-ray crystallography and cryo-electron microscopy. Structures of NSUN2 in complex with multiple tRNA substrates reveal a structure-first, sequence-tolerant strategy in which NSUN2 actively remodels tRNA architecture, exposing the buried target cytosine and positioning it within the catalytic pocket for methyl transfer. This recognition strategy enables NSUN2 to accommodate diverse tRNA substrates through a largely conserved interaction interface. Together, our findings define the molecular principles underlying NSUN2-mediated RNA mC modification.

PubMed: 42258135
DOI: 10.1007/s11427-026-3373-3

実験手法

ELECTRON MICROSCOPY (3.34 Å)