If you can’t beat them, join them: Anti-CRISPR proteins derived from CRISPR-associated genes

Bacteriophages have evolved numerous mechanisms to evade targeting by CRISPR-Cas defense systems. However, the evolutionary origin of these so-called “anti-CRISPRs” remains poorly understood. In a recent issue of Nature, Katz et al.1 provide evidence that some anti-CRISPRs were derived from genes of the CRISPR-Cas systems themselves. Bacteriophages have evolved numerous mechanisms to evade targeting by CRISPR-Cas defense systems. However, the evolutionary origin of these so-called “anti-CRISPRs” remains poorly understood. In a recent issue of Nature, Katz et al. provide evidence that some anti-CRISPRs were derived from genes of the CRISPR-Cas systems themselves.