A detailed understanding of the catalytic target DNA cleavage mechanism by CRISPR–Cas9 has been lacking. Now the key modulating role of Mg2+ in the conformational activation of Cas9 and the influence of active site residues on the protonation state of catalytic H840 are demonstrated, ultimately unravelling the catalytic mechanism.
- Łukasz Nierzwicki
- Kyle W. East
- Giulia Palermo