8XTS

Comamonas testosteroni KF-1 circularly permuted group II intron Pre-1S state

8XTS の概要

• エントリーDOI: 10.2210/pdb8xts/pdb
• EMDBエントリー: 38649
• 分子名称: RNA (814-MER), POTASSIUM ION, MAGNESIUM ION (3 entities in total)
• 機能のキーワード: cryoem, ribozyme, rna
• 由来する生物種: Comamonas testosteroni KF-1
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 265399.37

構造登録者

Wang, L.,Xie, J.H.,Zhang, C.,Zou, J.,Huang, Z.R.,Shang, S.T.,Chen, X.Y.,Yang, Y.,Liu, J.,Dong, H.H.,Huang, D.M.,Su, Z.M. (登録日: 2024-01-11, 公開日: 2025-02-12, 最終更新日: 2025-06-25)

主引用文献

Wang, L.,Xie, J.,Zhang, C.,Zou, J.,Huang, Z.,Shang, S.,Chen, X.,Yang, Y.,Liu, J.,Dong, H.,Huang, D.,Su, Z.
Structural basis of circularly permuted group II intron self-splicing.
Nat.Struct.Mol.Biol., 32:1091-1100, 2025

PubMed Abstract: Circularly permuted group II introns (CP introns) consist of rearranged structural domains separated by two tethered exons, generating branched introns and circular exons via back-splicing. Structural and mechanistic understanding of circular RNA (circRNA) generation by CP introns remains elusive. We resolve cryo-electron microscopy structures of a natural CP intron in different states during back-splicing at a resolution of 2.5-2.9 Å. Domain 6 (D6) undergoes a conformational change of 65° after branching, to facilitate 3'-exon recognition and circularization. Previously unseen tertiary interactions compact the catalytic triad and D6 for splicing without protein, whereas a metal ion, M, is observed to stabilize the 5'-exon during splicing. While these unique features were not observed in canonical group II introns and spliceosomes, they are common in CP introns, as demonstrated by the cryo-EM structure of another CP intron discovered by comparative genomics analysis. Our results elucidate the mechanism of CP intron back-splicing dynamics, with potential applications in circRNA research and therapeutics.

PubMed: 39890981
DOI: 10.1038/s41594-025-01484-x

実験手法

ELECTRON MICROSCOPY (2.54 Å)