4P6I

Crystal structure of the Cas1-Cas2 complex from Escherichia coli

Summary for 4P6I

• Entry DOI: 10.2210/pdb4p6i/pdb
• Descriptor: CRISPR-associated endoribonuclease Cas2, CRISPR-associated endonuclease Cas1 (3 entities in total)
• Functional Keywords: crispr-associated proteins, nuclease, hydrolase
• Biological source: Escherichia coli; More
• Total number of polymer chains: 6
• Total formula weight: 156048.21

Authors

Nunez, J.K.,Kranzusch, P.J.,Noeske, J.,Doudna, J.A. (deposition date: 2014-03-24, release date: 2014-05-07, Last modification date: 2023-12-27)

Primary citation

Nunez, J.K.,Kranzusch, P.J.,Noeske, J.,Wright, A.V.,Davies, C.W.,Doudna, J.A.
Cas1-Cas2 complex formation mediates spacer acquisition during CRISPR-Cas adaptive immunity.
Nat.Struct.Mol.Biol., 21:528-534, 2014

PubMed Abstract: The initial stage of CRISPR-Cas immunity involves the integration of foreign DNA spacer segments into the host genomic CRISPR locus. The nucleases Cas1 and Cas2 are the only proteins conserved among all CRISPR-Cas systems, yet the molecular functions of these proteins during immunity are unknown. Here we show that Cas1 and Cas2 from Escherichia coli form a stable complex that is essential for spacer acquisition and determine the 2.3-Å-resolution crystal structure of the Cas1-Cas2 complex. Mutations that perturb Cas1-Cas2 complex formation disrupt CRISPR DNA recognition and spacer acquisition in vivo. Active site mutants of Cas2, unlike those of Cas1, can still acquire new spacers, thus indicating a nonenzymatic role of Cas2 during immunity. These results reveal the universal roles of Cas1 and Cas2 and suggest a mechanism by which Cas1-Cas2 complexes specify sites of CRISPR spacer integration.

PubMed: 24793649
DOI: 10.1038/nsmb.2820

Experimental method

X-RAY DIFFRACTION (2.3 Å)