2VYZ:
reference: The Apolar Channel in Cerebratulus lacteus Hemoglobin Is the Route for O2 Entry and Exit., Salter MD, Nienhaus K, Nienhaus GU, Dewilde S, Moens L, Pesce A, Nardini M, Bolognesi M, Olson JS, J Biol Chem. 2008 Dec 19;283(51):35689-702. Epub 2008 Oct 7. PMID: 18840607

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