Figure 1.

3D structure of the α-lactalbumin Ca²⁺-binding site. Ribbon representation of the crystal structure of Ca²⁺-loaded human α-lactalbumin (Harata et al. 1999); PDB accession number 1B90. The Ca²⁺-binding site is magnified (rotated 180°) with the Ca²⁺-coordinating groups in yellow (K79 and D84 carbonyls, underlined, and D82, D87, and D88 carboxylate side chains). Ca²⁺ is red and Ca²⁺-coordinating water molecules are cyan. Figures were made in MOLMOL (Koradi et al. 1996) and rendered in Pov-Ray.