3DTU:
reference: A conserved steroid binding site in cytochrome C oxidase., Qin L, Mills DA, Buhrow L, Hiser C, Ferguson-Miller S, Biochemistry. 2008 Sep 23;47(38):9931-3. Epub 2008 Aug 30. PMID: 18759498

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