Fig. 4. Cartoon representation of the mutation spCas9- (PDB ID 5Y36) into nickases (D10A or H840A) and dead endonuclease (D10A and H840A). The Alanine residues were mutated to Asparagine and Histidine. The image was prepared using the PyMOL Molecular Graphics System, Version 2.0 Schrödinger, LLC.