Cooperation between CRISPR-Cas types enables adaptation in an RNA-targeting system
AbstractCRISPR-Cas immune systems adapt to new threats by acquiring spacers from invading nucleic acids such as phage genomes. However, some CRISPR-Cas loci lack genes necessary for spacer acquisition, despite apparent variation in spacer content between strains. It has been suggested that such loci may use acquisition machinery from co-occurring CRISPR-Cas systems. Here, using a lytic dsDNA phage, we observe spacer acquisition in the native host Flavobacterium columnare that carries an acquisition-deficient subtype VI-B locus and a complete subtype II-C locus. We characterize acquisition events in both loci and show that the RNA-targeting VI-B locus acquires spacers in trans using acquisit…
Cooperation between Different CRISPR-Cas Types Enables Adaptation in an RNA-Targeting System
CRISPR-Cas systems are immune systems that protect bacteria and archaea against their viruses, bacteriophages. Immunity is achieved through the acquisition of short DNA fragments from the viral invader’s genome.