8D4A image
Entry Detail
PDB ID:
8D4A
EMDB ID:
Title:
Cas12a2 quaternary complex
Biological Source:
PDB Version:
Deposition Date:
2022-06-01
Release Date:
2023-01-18
Method Details:
Experimental Method:
Resolution:
2.74 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:OrfB_Zn_ribbon domain-containing protein
Chain IDs:A
Chain Length:1232
Number of Molecules:1
Biological Source:Sulfuricurvum sp. PC08-66
Polymer Type:polyribonucleotide
Description:RNA (41-MER)
Chain IDs:B
Chain Length:41
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polyribonucleotide
Description:RNA (28-MER)
Chain IDs:C
Chain Length:28
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Description:DNA (5'-D(P*TP*TP*TP*TP*TP*TP*TP*TP*TP*TP*T)-3')
Chain IDs:D
Chain Length:11
Number of Molecules:1
Biological Source:synthetic construct
Polymer Type:polydeoxyribonucleotide
Description:DNA (5'-D(P*AP*AP*AP*AP*AP*AP*AP*AP*AP*AP*A)-3')
Chain IDs:E (auth: G)
Chain Length:11
Number of Molecules:1
Biological Source:synthetic construct
Primary Citation
RNA targeting unleashes indiscriminate nuclease activity of CRISPR-Cas12a2.
Nature 613 582 587 (2023)
PMID: 36599980 DOI: 10.1038/s41586-022-05560-w

Abstact

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.

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Primary Citation of related structures