Specificities and functional coordination between the two Cas6 maturation endonucleases in Anabaena sp. PCC 7120 assign orphan CRISPR arrays to three groups.

ABSTRACT: Many bacteria and archaea possess an RNA-guided adaptive and inheritable immune system that consists of clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins. In most CRISPR-Cas systems, the maturation of CRISPR-derived small RNAs (crRNAs) is essential for functionality. Cas6 endonucleases function as the most frequent CRISPR RNA maturation enzymes. In the cyanobacterium Anabaena sp. PCC 7120, ten CRISPR loci are present, but only two cas gene cassettes plus a Tn7-associated eleventh array. In this study, we deleted the two cas6 genes alr1482 (Type III-D) or alr1566 (Type I-D) and tested the specificities of the two corresponding enzymes in the resulting mutant strains, as recombinant proteins and in a ce

SUBMITTER: Reimann V 

PROVIDER: S-EPMC7549632 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature