1QHQ:
reference: Crystal structure of auracyanin, a "blue" copper protein from the green thermophilic photosynthetic bacterium Chloroflexus aurantiacus., Bond CS, Blankenship RE, Freeman HC, Guss JM, Maher MJ, Selvaraj FM, Wilce MC, Willingham KM, J Mol Biol 2001 Feb 9;306(1):47-67. PMID: 11178893

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