1F56:
reference: Crystal structure of plantacyanin, a basic blue cupredoxin from spinach., Einsle O, Mehrabian Z, Nalbandyan R, Messerschmidt A, J Biol Inorg Chem 2000 Oct;5(5):666-72. PMID: 11085657

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