Determining the role and function of Csm6 during type III-A anti-plasmid CRISPR immunity

The study was undertaken to determine what role the RNase Csm6 plays during anti-plasmid immunity in type III-A CRISPR systems. This ribonuclease was previously shown to be required for certain conditions, but why and how this is achieved was previously unknown. The current study determined that Csm6 is required when transcription across the target is weak, and Csm6 promotes plasmid clearance by non-specifically degrading transcripts required by the plasmid to replicate.Two RNA-seq experiments were performed; i) Sequencing to map the read depth across the natural spacer target of the conjugative plasmid pG0400, and ii) Sequencing in the presence and absence of active Csm6 to determine the RNA substrates of this RNase