title: Structure and activity of the RNA-targeting Type III-B CRISPR-Cas complex of Thermus thermophilus.
abstract: The CRISPR-Cas system is a prokaryotic host defense system against genetic elements. The Type III-B CRISPR-Cas system of the bacterium Thermus thermophilus, the TtCmr complex, is composed of six different protein subunits (Cmr1-6) and one crRNA with a stoichiometry of Cmr112131445361:crRNA1. The TtCmr complex copurifies with crRNA species of 40 and 46 nt, originating from a distinct subset of CRISPR loci and spacers. The TtCmr complex cleaves the target RNA at multiple sites with 6 nt intervals via a 5' ruler mechanism. Electron microscopy revealed that the structure of TtCmr resembles a "sea worm" and is composed of a Cmr2-3 heterodimer "tail," a helical backbone of Cmr4 subunits capped by Cmr5 subunits, and a curled "head" containing Cmr1 and Cmr6. Despite having a backbone of only four Cmr4 subunits and being both longer and narrower, the overall architecture of TtCmr resembles that of Type I Cascade complexes.
authors.affiliation: Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: Raymond H J
authors.initials: RHJ
authors.lastname: Staals
authors.affiliation: RIKEN SPring-8 Center, 679-5148 Hyogo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Agari
authors.affiliation: RIKEN SPring-8 Center, 679-5148 Hyogo, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Maki-Yonekura
authors.affiliation: Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520-8114, USA.|California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158-2330, USA.
authors.forename: David W
authors.initials: DW
authors.lastname: Taylor
authors.affiliation: Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, 3584 CH Utrecht, The Netherlands.
authors.forename: Esther
authors.initials: E
authors.lastname: van Duijn
authors.affiliation: Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, 3584 CH Utrecht, The Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: Barendregt
authors.affiliation: Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: Marnix
authors.initials: M
authors.lastname: Vlot
authors.affiliation: Laboratory of Systems and Synthetic Biology, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: Jasper J
authors.initials: JJ
authors.lastname: Koehorst
authors.affiliation: RIKEN SPring-8 Center, 679-5148 Hyogo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Global Research Cluster, RIKEN, Saitama 351-0198, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Masuda
authors.affiliation: Global Research Cluster, RIKEN, Saitama 351-0198, Japan.
authors.forename: Naoshi
authors.initials: N
authors.lastname: Dohmae
authors.affiliation: Laboratory of Systems and Synthetic Biology, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schaap
authors.affiliation: California Institute for Quantitative Biosciences, University of California, San Francisco, CA 94158-2330, USA.|Department of Molecular and Cell Biology, and Howard Hughes Medical Institute, University of California, Berkeley, CA 94720-3200, USA; Physical Biosciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720-3200, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Doudna
authors.affiliation: Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, 3584 CH Utrecht, The Netherlands.
authors.forename: Albert J R
authors.initials: AJR
authors.lastname: Heck
authors.affiliation: RIKEN SPring-8 Center, 679-5148 Hyogo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yonekura
authors.affiliation: Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, The Netherlands.
authors.forename: John
authors.initials: J
authors.lastname: van der Oost
authors.affiliation: RIKEN SPring-8 Center, 679-5148 Hyogo, Japan.
authors.forename: Akeo
authors.initials: A
authors.lastname: Shinkai
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D064130:CRISPR-Associated Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D064112:Clustered Regularly Interspaced Short Palindromic Repeats; D059014:High-Throughput Nucleotide Sequencing; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D021122:Protein Subunits; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012260:Ribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA; D021241:Spectrometry, Mass, Electrospray Ionization; D013329:Structure-Activity Relationship; D016963:Thermus thermophilus / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D064130:CRISPR-Associated Proteins; D021122:Protein Subunits; D012329:RNA, Bacterial; D012260:Ribonucleases