7XSO

Structure of the type III-E CRISPR-Cas effector gRAMP

7XSO の概要

• エントリーDOI: 10.2210/pdb7xso/pdb
• EMDBエントリー: 33429
• 分子名称: RAMP superfamily protein, RNA (35-MER), ZINC ION (3 entities in total)
• 機能のキーワード: immune system-rna complex, immune system/rna
• 由来する生物種: Candidatus Scalindua brodae; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 221826.55

構造登録者

Feng, Y.,Zhang, L. (登録日: 2022-05-15, 公開日: 2023-03-22, 最終更新日: 2025-06-25)

主引用文献

Liu, X.,Zhang, L.,Wang, H.,Xiu, Y.,Huang, L.,Gao, Z.,Li, N.,Li, F.,Xiong, W.,Gao, T.,Zhang, Y.,Yang, M.,Feng, Y.
Target RNA activates the protease activity of Craspase to confer antiviral defense.
Mol.Cell, 82:4503-4518.e8, 2022

PubMed Abstract: In the type III-E CRISPR-Cas system, a Cas effector (gRAMP) is associated with a TPR-CHAT to form Craspase (CRISPR-guided caspase). However, both the structural features of gRAMP and the immunity mechanism remain unknown for this system. Here, we report structures of gRAMP-crRNA and gRAMP:cRNA:target RNA as well as structures of Craspase and Craspase complexed with cognate target RNA (CTR) or non-cognate target RNA (NTR). Importantly, the 3' anti-tag region of NTR and CTR binds at two distinct channels in Craspase, and CTR with a non-complementary 3' anti-tag induces a marked conformational change of the TPR-CHAT, which allosterically activates its protease activity to cleave an ancillary protein Csx30. This cleavage then triggers an abortive infection as the antiviral strategy of the type III-E system. Together, our study provides crucial insights into both the catalytic mechanism of the gRAMP and the immunity mechanism of the type III-E system.

PubMed: 36306795
DOI: 10.1016/j.molcel.2022.10.007

実験手法

ELECTRON MICROSCOPY (3.01 Å)