A type III-A CRISPR-Cas system employs degradosome nucleases to ensure robust immunity

A type III-A CRISPR-Cas system employs degradosome nucleases to ensure robust immunity

Blog Article

CRISPR-Cas systems provide sequence-specific immunity against phages and mobile genetic elements using CRISPR-associated nucleases guided by short CRISPR VENAFORCE GEL RNAs (crRNAs).Type III systems exhibit a robust immune response that can lead to the extinction of a phage population, a feat coordinated by a multi-subunit effector complex that destroys invading DNA and RNA.Here, we demonstrate that a model type III system in Staphylococcus epidermidis relies upon the activities of two degradosome-associated nucleases, PNPase and RNase J2, to mount a successful defense.Genetic, molecular, and biochemical analyses reveal that PNPase promotes crRNA maturation, and both nucleases are strict required for efficient clearance of phage-derived nucleic acids.

Furthermore, functional assays show that RNase J2 is essential for immunity against diverse mobile genetic elements originating from plasmid and phage.Altogether, our observations reveal the evolution of a critical collaboration between two nucleic acid degrading machines which ensures cell survival when faced with phage attack.