RRC ID 50344
Author Staals RH, Zhu Y, Taylor DW, Kornfeld JE, Sharma K, Barendregt A, Koehorst JJ, Vlot M, Neupane N, Varossieau K, Sakamoto K, Suzuki T, Dohmae N, Yokoyama S, Schaap PJ, Urlaub H, Heck AJ, Nogales E, Doudna JA, Shinkai A, van der Oost J.
Title RNA targeting by the type III-A CRISPR-Cas Csm complex of Thermus thermophilus.
Journal Mol. Cell
Abstract CRISPR-Cas is a prokaryotic adaptive immune system that provides sequence-specific defense against foreign nucleic acids. Here we report the structure and function of the effector complex of the Type III-A CRISPR-Cas system of Thermus thermophilus: the Csm complex (TtCsm). TtCsm is composed of five different protein subunits (Csm1-Csm5) with an uneven stoichiometry and a single crRNA of variable size (35-53 nt). The TtCsm crRNA content is similar to the Type III-B Cmr complex, indicating that crRNAs are shared among different subtypes. A negative stain EM structure of the TtCsm complex exhibits the characteristic architecture of Type I and Type III CRISPR-associated ribonucleoprotein complexes. crRNA-protein crosslinking studies show extensive contacts between the Csm3 backbone and the bound crRNA. We show that, like TtCmr, TtCsm cleaves complementary target RNAs at multiple sites. Unlike Type I complexes, interference by TtCsm does not proceed via initial base pairing by a seed sequence.
Volume 56(4)
Pages 518-30
Published 2014-11-20
DOI 10.1016/j.molcel.2014.10.005
PII S1097-2765(14)00789-8
PMID 25457165
PMC PMC4342149
MeSH Amino Acid Sequence Bacterial Proteins / chemistry Bacterial Proteins / metabolism* Bacterial Proteins / ultrastructure Base Sequence CRISPR-Associated Proteins / chemistry CRISPR-Associated Proteins / metabolism* CRISPR-Associated Proteins / ultrastructure Clustered Regularly Interspaced Short Palindromic Repeats* Endoribonucleases / chemistry Endoribonucleases / metabolism Endoribonucleases / ultrastructure Microscopy, Electron Models, Molecular Molecular Sequence Data Protein Binding Protein Structure, Quaternary RNA Cleavage* RNA, Bacterial / genetics RNA, Bacterial / metabolism Thermus thermophilus / enzymology Thermus thermophilus / genetics*
IF 14.248
Resource
DNA material pUC-csm5h (RDB15776).