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-Structure paper
Title | RNA targeting unleashes indiscriminate nuclease activity of CRISPR-Cas12a2. |
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Journal, issue, pages | Nature, Vol. 613, Issue 7944, Page 582-587, Year 2023 |
Publish date | Jan 4, 2023 |
Authors | Jack P K Bravo / Thomson Hallmark / Bronson Naegle / Chase L Beisel / Ryan N Jackson / David W Taylor / |
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 ...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. |
External links | Nature / PubMed:36599980 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.74 - 3.2 Å |
Structure data | EMDB-27178, PDB-8d49: EMDB-27179: Structure of Cas12a2 ternary complex EMDB-27180, PDB-8d4b: |
Chemicals | ChemComp-ZN: ChemComp-MG: ChemComp-HOH: |
Source |
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Keywords | DNA Binding Protein/RNA / Cas12a2 / CRISPR / Nuclease / DNA Binding Protein-RNA complex / DNA Binding Protein/RNA/DNA / DNA Binding Protein-RNA-DNA complex |