Discovery of widespread type I and type V CRISPR-Cas inhibitors.

Marino, Nicole D; Zhang, Jenny Y; Borges, Adair L; Sousa, Alexander A; Leon, Lina M; Rauch, Benjamin J; Walton, Russell T; Berry, Joel D et al. · Science · 2018

basic_science · Level V

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Abstract

Bacterial CRISPR-Cas systems protect their host from bacteriophages and other mobile genetic elements. Mobile elements, in turn, encode various anti-CRISPR (Acr) proteins to inhibit the immune function of CRISPR-Cas. To date, Acr proteins have been discovered for type I (subtypes I-D, I-E, and I-F) and type II (II-A and II-C) but not other CRISPR systems. Here, we report the discovery of 12 <i>acr</i> genes, including inhibitors of type V-A and I-C CRISPR systems. AcrVA1 inhibits a broad spectrum of Cas12a (Cpf1) orthologs-including MbCas12a, Mb3Cas12a, AsCas12a, and LbCas12a-when assayed in human cells. The <i>acr</i> genes reported here provide useful biotechnological tools and mark the discovery of <i>acr</i> loci in many bacteria and phages.

Medical subject headings