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Publication Abstract from PubMed

Clustered regularly interspaced short palindromic repeats (CRISPR) and their associated Cas proteins provide an immune-like response in many prokaryotes against extraneous nucleic acids. CRISPR-Cas systems are classified into different classes and types. Class 1 CRISPR-Cas systems form multi-protein effector complexes that includes a guide RNA (crRNA) used to identify the target for destruction. Here we present crystal structures of Staphylococcus epidermidis Type III-A CRISPR subunits Csm2 and Csm3 and a 5.2 A resolution single-particle cryo-electron microscopy (cryo-EM) reconstruction of an in vivo assembled effector subcomplex including the crRNA. The structures help to clarify the quaternary architecture of Type III-A effector complexes, and provide details on crRNA binding, target RNA binding and cleavage, and intermolecular interactions essential for effector complex assembly. The structures allow a better understanding of the organization of Type III-A CRISPR effector complexes as well as highlighting the overall similarities and differences with other Class 1 effector complexes.

Structural organization of a Type III-A CRISPR effector subcomplex determined by X-ray crystallography and cryo-EM.,Dorsey BW, Huang L, Mondragon A Nucleic Acids Res. 2019 Feb 13. pii: 5310821. doi: 10.1093/nar/gkz079. PMID:30759237^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.