1RCY:
reference: Multiple wavelength anomalous diffraction (MAD) crystal structure of rusticyanin: a highly oxidizing cupredoxin with extreme acid stability., Walter RL, Ealick SE, Friedman AM, Blake RC 2nd, Proctor P, Shoham M, J Mol Biol 1996 Nov 15;263(5):730-51. PMID: 8947572

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