5DS5

Crystal structure the Escherichia coli Cas1-Cas2 complex bound to protospacer DNA and Mg

Summary for 5DS5

• Entry DOI: 10.2210/pdb5ds5/pdb
• Related: 4P6I 5DS4 5DS6
• Descriptor: CRISPR-associated endonuclease Cas1, CRISPR-associated endoribonuclease Cas2, DNA (28-MER), ... (5 entities in total)
• Functional Keywords: adaptive immunity, crispr-associated proteins, crispr-cas systems, clustered regularly interspaced short palindromic repeats, integrases, endodeoxyribonucleases, endonucleases, dna binding protein, hydrolase-dna complex, hydrolase/dna
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 8
• Total formula weight: 173995.57

Authors

Nunez, J.K.,Harrington, L.B.,Kranzusch, P.J.,Engelman, A.N.,Doudna, J.A. (deposition date: 2015-09-16, release date: 2015-10-28, Last modification date: 2023-09-27)

Primary citation

Nunez, J.K.,Harrington, L.B.,Kranzusch, P.J.,Engelman, A.N.,Doudna, J.A.
Foreign DNA capture during CRISPR-Cas adaptive immunity.
Nature, 527:535-538, 2015

PubMed Abstract: Bacteria and archaea generate adaptive immunity against phages and plasmids by integrating foreign DNA of specific 30-40-base-pair lengths into clustered regularly interspaced short palindromic repeat (CRISPR) loci as spacer segments. The universally conserved Cas1-Cas2 integrase complex catalyses spacer acquisition using a direct nucleophilic integration mechanism similar to retroviral integrases and transposases. How the Cas1-Cas2 complex selects foreign DNA substrates for integration remains unknown. Here we present X-ray crystal structures of the Escherichia coli Cas1-Cas2 complex bound to cognate 33-nucleotide protospacer DNA substrates. The protein complex creates a curved binding surface spanning the length of the DNA and splays the ends of the protospacer to allow each terminal nucleophilic 3'-OH to enter a channel leading into the Cas1 active sites. Phosphodiester backbone interactions between the protospacer and the proteins explain the sequence-nonspecific substrate selection observed in vivo. Our results uncover the structural basis for foreign DNA capture and the mechanism by which Cas1-Cas2 functions as a molecular ruler to dictate the sequence architecture of CRISPR loci.

PubMed: 26503043
DOI: 10.1038/nature15760

Experimental method

X-RAY DIFFRACTION (2.951 Å)