Compute Annotations for Structure 4. Create the 1HAB Glu6Val mutant by clicking on E at position 6 and by Putting Val in the Mutant Amino Acid window for both the B and the D chains. There is only one difference between the beta chain sequence of the normal hemoglobin, and the one found in the hemoglobin of people who have sickle cell anemia. The alpha chains are colored in yellow and the beta chains are colored in blue. The red disks represent the heme groups.
Heme groups are the part of hemoglobin that binds the oxygen molecules.
Each heme group contains an iron atom that is held in the center of the heme. The iron is responsible for the oxygen-binding activities of hemoglobin. Note that the glu 6 residues are in the outside of the molecule. You may notice that there are actually 2 hemoglobin tetramers in this sickle cell hemoglobin image. Valine is hydrophobic, so it would prefer to be associated with other hydrophobic amino acids.