3GOD

Structural basis for DNase activity of a conserved protein implicated in CRISPR-mediated antiviral defense

Summary for 3GOD

• Entry DOI: 10.2210/pdb3god/pdb
• Descriptor: Cas1, MANGANESE (II) ION, SODIUM ION, ... (5 entities in total)
• Functional Keywords: crispr, crispr-associated cas1, metallonuclease, dnase, prokaryotic immune system, immune system
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 4
• Total formula weight: 147097.64

Authors

Wiedenheft, B. (deposition date: 2009-03-18, release date: 2009-06-30, Last modification date: 2024-11-06)

Primary citation

Wiedenheft, B.,Zhou, K.,Jinek, M.,Coyle, S.M.,Ma, W.,Doudna, J.A.
Structural Basis for DNase Activity of a Conserved Protein Implicated in CRISPR-Mediated Genome Defense.
Structure, 17:904-912, 2009

PubMed Abstract: Acquired immunity in prokaryotes is achieved by integrating short fragments of foreign nucleic acids into clustered regularly interspaced short palindromic repeats (CRISPRs). This nucleic acid-based immune system is mediated by a variable cassette of up to 45 protein families that represent distinct immune system subtypes. CRISPR-associated gene 1 (cas1) encodes the only universally conserved protein component of CRISPR immune systems, yet its function is unknown. Here we show that the Cas1 protein is a metal-dependent DNA-specific endonuclease that produces double-stranded DNA fragments of approximately 80 base pairs in length. The 2.2 A crystal structure of the Cas1 protein reveals a distinct fold and a conserved divalent metal ion-binding site. Mutation of metal ion-binding residues, chelation of metal ions, or metal-ion substitution inhibits Cas1-catalyzed DNA degradation. These results provide a foundation for understanding how Cas1 contributes to CRISPR function, perhaps as part of the machinery for processing foreign nucleic acids.

PubMed: 19523907
DOI: 10.1016/j.str.2009.03.019

Experimental method

X-RAY DIFFRACTION (2.17 Å)