1D6Y:
reference: Visualization of dioxygen bound to copper during enzyme catalysis., Wilmot CM, Hajdu J, McPherson MJ, Knowles PF, Phillips SE, Science 1999 Nov 26;286(5445):1724-8. PMID: 10576737

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