6OPM

Casposase bound to integration product

Summary for 6OPM

• Entry DOI: 10.2210/pdb6opm/pdb
• Descriptor: CRISPR-associated endonuclease Cas1, DNA 21-mer, unknown, ... (5 entities in total)
• Functional Keywords: transposition, casposase, hydrolase-dna complex, hydrolase/dna
• Biological source: Methanosarcina mazei; More
• Total number of polymer chains: 8
• Total formula weight: 215101.47

Authors

Dyda, F.,Hickman, A.B.,Kailasan, S. (deposition date: 2019-04-25, release date: 2020-02-12, Last modification date: 2024-11-20)

Primary citation

Hickman, A.B.,Kailasan, S.,Genzor, P.,Haase, A.D.,Dyda, F.
Casposase structure and the mechanistic link between DNA transposition and spacer acquisition by CRISPR-Cas.
Elife, 9:-, 2020

PubMed Abstract: Key to CRISPR-Cas adaptive immunity is maintaining an ongoing record of invading nucleic acids, a process carried out by the Cas1-Cas2 complex that integrates short segments of foreign genetic material (spacers) into the CRISPR locus. It is hypothesized that Cas1 evolved from casposases, a novel class of transposases. We show here that the casposase can integrate varied forms of the casposon end in vitro, and recapitulates several properties of CRISPR-Cas integrases including site-specificity. The X-ray structure of the casposase bound to DNA representing the product of integration reveals a tetramer with target DNA bound snugly between two dimers in which single-stranded casposon end binding resembles that of spacer 3'-overhangs. The differences between transposase and CRISPR-Cas integrase are largely architectural, and it appears that evolutionary change involved changes in protein-protein interactions to favor Cas2 binding over tetramerization; this in turn led to preferred integration of single spacers over two transposon ends.

PubMed: 31913120
DOI: 10.7554/eLife.50004

Experimental method

X-RAY DIFFRACTION (3.1 Å)