Figure 5

Structural superposition of the three-dimensional structure of the αβ dimer of Hb bound to Hp (cyan; PDB code 5JDO)43 to the corresponding subunits of the Hb tetramer in the R-state (light brown; PDB code 2DN1)42. The heme-Fe moieties are shown in stick representation. Iron atoms are represented by orange spheres and O2 molecules as red sticks. The figure has been drawn using the UCSF Chimera software52.