EMD-27179

Single-particle
2.74 Å
EMD-27179 Deposition: 01/06/2022
Map released: 18/01/2023
Last modified: 12/06/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-27179

Structure of Cas12a2 ternary complex

EMD-27179

Single-particle
2.74 Å
EMD-27179 Deposition: 01/06/2022
Map released: 18/01/2023
Last modified: 12/06/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: synthetic construct, Sulfuricurvum sp. PC08-66
Sample: Cas12a2 ternary complex
Fitted models: 8d4a (Avg. Q-score: 0.588)

Deposition Authors: Bravo JPK, Taylor DW
RNA targeting unleashes indiscriminate nuclease activity of CRISPR-Cas12a2.
Bravo JPK, Hallmark T , Naegle B, Beisel CL , Jackson RN , Taylor DW
(2023) Nature , 613 , 582 - 587
PUBMED: 36599980
DOI: doi:10.1038/s41586-022-05560-w
ISSN: 1476-4687
ASTM: NATUAS
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 infection1. 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.