Myoglobin1

Myoglobin is a protein that binds oxygen and contains a heme group and protoporphyrin IX. The heme group coordinates with the protein through bonds and forms pockets on the protein surface where other molecules can bind. Visualizations of myoglobin show its secondary structure as a ribbon including side chains of hydrophobic residues, and a space-filling model depicting all amino acid side chains and how steric effects impact ligand binding to the heme group.