3MPH:
reference: Correlation of Active Site Metal Content in Human Diamine Oxidase with Trihydroxyphenylalanine Quinone Cofactor Biogenesis ., McGrath AP, Caradoc-Davies T, Collyer CA, Guss JM, Biochemistry. 2010 Sep 1. PMID: 20722416

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