8D4B

Structure of Cas12a2 ternary complex

8D4B の概要

• エントリーDOI: 10.2210/pdb8d4b/pdb
• EMDBエントリー: 27180
• 分子名称: OrfB_Zn_ribbon domain-containing protein, RNA (41-MER), RNA (28-MER) (3 entities in total)
• 機能のキーワード: cas12a2, crispr, nuclease, dna binding protein-rna complex, dna binding protein/rna
• 由来する生物種: Sulfuricurvum sp. PC08-66; 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 165258.91

構造登録者

Bravo, J.P.K.,Taylor, D.W. (登録日: 2022-06-01, 公開日: 2023-01-18, 最終更新日: 2025-06-04)

主引用文献

Bravo, J.P.K.,Hallmark, T.,Naegle, B.,Beisel, C.L.,Jackson, R.N.,Taylor, D.W.
RNA targeting unleashes indiscriminate nuclease activity of CRISPR-Cas12a2.
Nature, 613:582-587, 2023

PubMed Abstract: Cas12a2 is a CRISPR-associated nuclease that performs RNA-guided, sequence-nonspecific degradation of single-stranded RNA, single-stranded DNA and double-stranded DNA following recognition of a complementary RNA target, culminating in abortive infection. Here we report structures of Cas12a2 in binary, ternary and quaternary complexes to reveal a complete activation pathway. Our structures reveal that Cas12a2 is autoinhibited until binding a cognate RNA target, which exposes the RuvC active site within a large, positively charged cleft. Double-stranded DNA substrates are captured through duplex distortion and local melting, stabilized by pairs of 'aromatic clamp' residues that are crucial for double-stranded DNA degradation and in vivo immune system function. Our work provides a structural basis for this mechanism of abortive infection to achieve population-level immunity, which can be leveraged to create rational mutants that degrade a spectrum of collateral substrates.

PubMed: 36599980
DOI: 10.1038/s41586-022-05560-w

実験手法

ELECTRON MICROSCOPY (2.92 Å)