Figure 2.

Fully optimized Ca²⁺, Mg²⁺ and Sr²⁺-loaded metal binding sites of the active-state CaSR: (a) Site 1, (b) Site 3 and (c) Site 4 (drawn by CYLview visualization software [23]) and energy penalties (in kcal/mol) for Sr²⁺ and Mg²⁺ structures (∆Ep = E(partial optimization) − E(full optimization); see text).