1GVH:
reference: The X-ray structure of ferric Escherichia coli flavohemoglobin reveals an unexpected geometry of the distal heme pocket., Ilari A, Bonamore A, Farina A, Johnson KA, Boffi A, J Biol Chem 2002 Jun 28;277(26):23725-32. PMID: 11964402

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