1ZYY:
reference: A structural model for the adduct between cytochrome c and cytochrome c oxidase., Bertini I, Cavallaro G, Rosato A, J Biol Inorg Chem. 2005 Oct;10(6):613-24. Epub 2005 Nov 2. PMID: 16151864

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