1DWT:
reference: Structure of a ligand-binding intermediate in wild-type carbonmonoxy myoglobin., Chu K, Vojtchovsky J, McMahon BH, Sweet RM, Berendzen J, Schlichting I, Nature. 2000 Feb 24;403(6772):921-3. PMID: 10706294

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