FIGURE 6.

Oxygen heme moiety. Least square superposition of HbII_Lp (yellow) and Hb_Asc (cyan, PDB code 1ASH). The superposition was carried out taking into account all the residues in the structure (amino acids and prosthetic group). The water molecule forming a hydrogen bond between the propionate group and His⁹⁷(F8) in HbII_Lp is also shown. This water molecule is not present in the oxygen bound structure of Hb_Asc. The oxygen molecule shows opposite orientation in both structures (the oxygen molecule in Hb_Asc is shown in clear cyan).