6QXT

Cas1-Cas2-Csn2-DNA dimer complex from the Type II-A CRISPR-Cas system

Summary for 6QXT

• Entry DOI: 10.2210/pdb6qxt/pdb
• Related: 6QXF 6QY3
• EMDB information: 4668 4670 4671
• Descriptor: CRISPR-associated protein Csn2, CRISPR-associated endonuclease Cas1, CRISPR-associated endoribonuclease Cas2, ... (6 entities in total)
• Functional Keywords: crispr, cas, dna binding, nuclease, adaptation, spacer acquisition, dna binding protein, protein complex, protein-dna complex, calcium, metal-binding, antiviral
• Biological source: Streptococcus thermophilus; More
• Total number of polymer chains: 54
• Total formula weight: 1458502.25

Authors

Wilkinson, M.,Drabavicius, G.,Silanskas, A.,Gasiunas, G.,Siksnys, V.,Wigley, D.B. (deposition date: 2019-03-08, release date: 2019-05-08, Last modification date: 2024-05-15)

Primary citation

Wilkinson, M.,Drabavicius, G.,Silanskas, A.,Gasiunas, G.,Siksnys, V.,Wigley, D.B.
Structure of the DNA-Bound Spacer Capture Complex of a Type II CRISPR-Cas System.
Mol.Cell, 75:90-101.e5, 2019

PubMed Abstract: CRISPR and associated Cas proteins function as an adaptive immune system in prokaryotes to combat bacteriophage infection. During the immunization step, new spacers are acquired by the CRISPR machinery, but the molecular mechanism of spacer capture remains enigmatic. We show that the Cas9, Cas1, Cas2, and Csn2 proteins of a Streptococcus thermophilus type II-A CRISPR-Cas system form a complex and provide cryoelectron microscopy (cryo-EM) structures of three different assemblies. The predominant form, with the stoichiometry Cas1-Cas2-Csn2, referred to as monomer, contains ∼30 bp duplex DNA bound along a central channel. A minor species, termed a dimer, comprises two monomers that sandwich a further eight Cas1 and four Cas2 subunits and contains two DNA ∼30-bp duplexes within the channel. A filamentous form also comprises Cas1-Cas2-Csn2 units (typically 2-6) but with a different Cas1-Cas2 interface between them and a continuous DNA duplex running along a central channel.

PubMed: 31080012
DOI: 10.1016/j.molcel.2019.04.020

Experimental method

ELECTRON MICROSCOPY (8.9 Å)