3PBJ:
reference: Hydrolytic catalysis and structural stabilization in a designed metalloprotein., Zastrow ML, Peacock AF, Stuckey JA, Pecoraro VL, Nat Chem. 2011 Nov 27;4(2):118-23. doi: 10.1038/nchem.1201. PMID: 22270627

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