title: Cutting it close: CRISPR-associated endoribonuclease structure and function.
abstract: Many bacteria and archaea possess an adaptive immune system consisting of repetitive genetic elements known as clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins. Similar to RNAi pathways in eukaryotes, CRISPR-Cas systems require small RNAs for sequence-specific detection and degradation of complementary nucleic acids. Cas5 and Cas6 enzymes have evolved to specifically recognize and process CRISPR-derived transcripts into functional small RNAs used as guides by interference complexes. Our detailed understanding of these proteins has led to the development of several useful Cas6-based biotechnological methods. Here, we review the structures, functions, mechanisms, and applications of the enzymes responsible for CRISPR RNA (crRNA) processing, highlighting a fascinating family of endonucleases with exquisite RNA recognition and cleavage activities.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
authors.forename: Megan L
authors.initials: ML
authors.lastname: Hochstrasser
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, CA 94720, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. Electronic address: doudna@berkeley.edu.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Doudna
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000276:immunology; D064130:CRISPR-Associated Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D064113:CRISPR-Cas Systems / Q000235:genetics*; D004722:Endoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding; D012313:RNA / Q000737:chemistry / Q000235:genetics; D034622:RNA Interference; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D064130:CRISPR-Associated Proteins; D012313:RNA; D004722:Endoribonucleases
keywords: CRISPR–Cas; Cas5; Cas6; crRNA; endoribonuclease; structure and function