TY - JOUR
T1 - Crystal structure of the Csm3-Csm4 subcomplex in the type III-A CRISPR-Cas interference complex
AU - Numata, Tomoyuki
AU - Inanaga, Hideko
AU - Sato, Chikara
AU - Osawa, Takuo
N1 - Funding Information:
We thank the beam-line staff at BL-17A of the Photon Factory (Ibaraki, Japan) for technical assistance during data collection. This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology to T.N. and C.S. and by a Grant-in-Aid for Young Scientists from the Japan Society for the Promotion of Science to T.N.
Publisher Copyright:
© 2014 Elsevier Ltd. All rights reserved.
PY - 2015/1/30
Y1 - 2015/1/30
N2 - Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci play a pivotal role in the prokaryotic host defense system against invading genetic materials. The CRISPR loci are transcribed to produce CRISPR RNAs (crRNAs), which form interference complexes with CRISPR-associated (Cas) proteins to target the invading nucleic acid for degradation. The interference complex of the type III-A CRISPR-Cas system is composed of five Cas proteins (Csm1-Csm5) and a crRNA, and targets invading DNA. Here, we show that the Csm1, Csm3, and Csm4 proteins from Methanocaldococcus jannaschii form a stable subcomplex. We also report the crystal structure of the M. jannaschii Csm3-Csm4 subcomplex at 3.1 A˚ resolution. The complex structure revealed the presence of a basic concave surface around their interface, suggesting the RNA and/or DNA binding ability of the complex. A gel retardation analysis showed that the Csm3-Csm4 complex binds single-stranded RNA in a non-sequence-specific manner. Csm4 structurally resembles Cmr3, a component of the type III-B CRISPR-Cas interference complex. Based on bioinformatics, we constructed a model structure of the Csm1-Csm4-Csm3 ternary complex, which provides insights into its role in the Csm interference complex.
AB - Clustered, regularly interspaced, short palindromic repeat (CRISPR) loci play a pivotal role in the prokaryotic host defense system against invading genetic materials. The CRISPR loci are transcribed to produce CRISPR RNAs (crRNAs), which form interference complexes with CRISPR-associated (Cas) proteins to target the invading nucleic acid for degradation. The interference complex of the type III-A CRISPR-Cas system is composed of five Cas proteins (Csm1-Csm5) and a crRNA, and targets invading DNA. Here, we show that the Csm1, Csm3, and Csm4 proteins from Methanocaldococcus jannaschii form a stable subcomplex. We also report the crystal structure of the M. jannaschii Csm3-Csm4 subcomplex at 3.1 A˚ resolution. The complex structure revealed the presence of a basic concave surface around their interface, suggesting the RNA and/or DNA binding ability of the complex. A gel retardation analysis showed that the Csm3-Csm4 complex binds single-stranded RNA in a non-sequence-specific manner. Csm4 structurally resembles Cmr3, a component of the type III-B CRISPR-Cas interference complex. Based on bioinformatics, we constructed a model structure of the Csm1-Csm4-Csm3 ternary complex, which provides insights into its role in the Csm interference complex.
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U2 - 10.1016/j.jmb.2014.09.029
DO - 10.1016/j.jmb.2014.09.029
M3 - Article
C2 - 25451598
AN - SCOPUS:84920817752
SN - 0022-2836
VL - 427
SP - 259
EP - 273
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 2
ER -