title: A Conserved Structural Chassis for Mounting Versatile CRISPR RNA-Guided Immune Responses.
abstract: Bacteria and archaea rely on CRISPR (clustered regularly interspaced short palindromic repeats) RNA-guided adaptive immune systems for targeted elimination of foreign nucleic acids. These immune systems have been divided into three main types, and the first atomic-resolution structure of a type III RNA-guided immune complex provides new insights into the mechanisms of nucleic acid degradation. Here we compare the crystal structure of a type III complex to recently determined structures of DNA-targeting type I CRISPR complexes. Structural comparisons support previous assertions that type I and type III systems share a common ancestor and reveal how a conserved structural chassis is used to support RNA-, DNA-, or both RNA- and DNA-targeting mechanisms.
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Ryan N
authors.initials: RN
authors.lastname: Jackson
authors.affiliation: Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA. Electronic address: bwiedenheft@gmail.com.
authors.forename: Blake
authors.initials: B
authors.lastname: Wiedenheft
mesh_terms: D001105:Archaea / Q000821:virology*; D001419:Bacteria / Q000821:virology*; D064130:CRISPR-Associated Proteins / Q000737:chemistry; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D008958:Models, Molecular; D010802:Phylogeny; D011485:Protein Binding; D011487:Protein Conformation; D019642:RNA, Archaeal / Q000737:chemistry / Q000502:physiology; D012329:RNA, Bacterial / Q000737:chemistry / Q000502:physiology
chemical_list: D064130:CRISPR-Associated Proteins; D019642:RNA, Archaeal; D012329:RNA, Bacterial