3X2Q:
reference: X-ray structure of cyanide-bound bovine heart cytochrome c oxidase in the fully oxidized state at 2.0 A resolution., Yano N, Muramoto K, Mochizuki M, Shinzawa-Itoh K, Yamashita E, Yoshikawa S, Tsukihara T, Acta Crystallogr F Struct Biol Commun. 2015 Jun;71(Pt 6):726-30. doi:, 10.1107/S2053230X15007025. Epub 2015 May 22. PMID: 26057802

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