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-Structure paper
Title | A phage-encoded anti-CRISPR enables complete evasion of type VI-A CRISPR-Cas immunity. |
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Journal, issue, pages | Science, Vol. 369, Issue 6499, Page 54-59, Year 2020 |
Publish date | Jul 3, 2020 |
Authors | Alexander J Meeske / Ning Jia / Alice K Cassel / Albina Kozlova / Jingqiu Liao / Martin Wiedmann / Dinshaw J Patel / Luciano A Marraffini / |
PubMed Abstract | The CRISPR RNA (crRNA)-guided nuclease Cas13 recognizes complementary viral transcripts to trigger the degradation of both host and viral RNA during the type VI CRISPR-Cas antiviral response. ...The CRISPR RNA (crRNA)-guided nuclease Cas13 recognizes complementary viral transcripts to trigger the degradation of both host and viral RNA during the type VI CRISPR-Cas antiviral response. However, how viruses can counteract this immunity is not known. We describe a listeriaphage (ϕLS46) encoding an anti-CRISPR protein (AcrVIA1) that inactivates the type VI-A CRISPR system of Using genetics, biochemistry, and structural biology, we found that AcrVIA1 interacts with the guide-exposed face of Cas13a, preventing access to the target RNA and the conformational changes required for nuclease activation. Unlike inhibitors of DNA-cleaving Cas nucleases, which cause limited immunosuppression and require multiple infections to bypass CRISPR defenses, a single dose of AcrVIA1 delivered by an individual virion completely dismantles type VI-A CRISPR-mediated immunity. |
External links | Science / PubMed:32467331 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.0 - 3.2 Å |
Structure data | EMDB-21366, PDB-6vrb: EMDB-21367, PDB-6vrc: |
Source |
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Keywords | IMMUNE SYSTEM / CRISPR-Cas system / Cas13 / type VIA / Anti-CRISPR / HYDROLASE / RNA / TypeVI |