1F5P:
reference: Crystalline ligand transitions in lamprey hemoglobin. Structural evidence for the regulation of oxygen affinity., Heaslet HA, Royer WE Jr, J Biol Chem 2001 Jul 13;276(28):26230-6. PMID: 11340069

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