Introduction - This script shows the structure of oxy-myoglobin (MbO2).
Scroll down until the text corresponding to the view is visible.
(Based on 1mbo.pdb, S.E.V. Phillips J.Mol.Biol..
142 531(1980)). Notice the dioxygen ligand bound to the heme Fe(II).
Most of the heme is buried within the protein. The carboxyl
groups of the heme are exposed to the solvent.
Inside the protein the iron is coordinated to
HIS93, the "proximal" histidine.
HIS64, the "distal"
histidine also plays an important role in Mb and Hb.