2PCY:
reference: The crystal structure of poplar apoplastocyanin at 1.8-A resolution. The geometry of the copper-binding site is created by the polypeptide., Garrett TP, Clingeleffer DJ, Guss JM, Rogers SJ, Freeman HC, J Biol Chem 1984 Mar 10;259(5):2822-5. PMID: 6698995

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