3TYI:
reference: Protein camouflage in cytochrome c-calixarene complexes., McGovern RE, Fernandes H, Khan AR, Power NP, Crowley PB, Nat Chem. 2012 Apr 29;4(7):527-33. doi: 10.1038/nchem.1342. PMID: 22717436

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