Download MendeleyStructural organization of a Type III-A CRISPR effector subcomplex determined by X-ray crystallography and cryo-EM.
Dorsey, B.W., Huang, L., Mondragon, A.(2019) Nucleic Acids Res 47: 3765-3783
- PubMed: 30759237
- DOI: https://doi.org/10.1093/nar/gkz079
- Primary Citation of Related Structures:
6NBT, 6NBU - PubMed Abstract:
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 Å 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.
Organizational Affiliation:
Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
