4QTS

Crystal structure of Csm3-Csm4 subcomplex in the type III-A CRISPR-Cas interference complex

Summary for 4QTS

• Entry DOI: 10.2210/pdb4qts/pdb
• Descriptor: CRISPR type III-associated RAMP protein Csm4, CRISPR type III-associated RAMP protein Csm3, ZINC ION (3 entities in total)
• Functional Keywords: crispr-associated protein, ferredoxin-like fold, type iii-a crispr-cas system, rna binding protein
• Biological source: Methanocaldococcus jannaschii DSM 2661; More
• Total number of polymer chains: 4
• Total formula weight: 148731.35

Authors

Numata, T.,Inanaga, H.,Osawa, T. (deposition date: 2014-07-09, release date: 2014-12-24, Last modification date: 2024-05-29)

Primary citation

Numata, T.,Inanaga, H.,Sato, C.,Osawa, T.
Crystal structure of the Csm3-Csm4 subcomplex in the type III-A CRISPR-Cas interference complex.
J.Mol.Biol., 427:259-273, 2015

PubMed Abstract: 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 3.1Å 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.

PubMed: 25451598
DOI: 10.1016/j.jmb.2014.09.029

Experimental method

X-RAY DIFFRACTION (3.105 Å)