4UN3:
reference: Structural basis of PAM-dependent target DNA recognition by the Cas9 endonuclease., Anders C, Niewoehner O, Duerst A, Jinek M, Nature. 2014 Jul 27. doi: 10.1038/nature13579. PMID: 25079318

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).