Figure 6.

Representative $\mathrm{2}:\mathrm{1}$ $\mathrm{idoxifene}:\mathrm{CaM}$ complex structures. Panels (a) and (b) are orthogonal views of the $\mathrm{2}:\mathrm{1}$ $\mathrm{idoxifene}:\mathrm{CaM}$ complex calculated using NOE-restrained docking of two molecules of idoxifene to CaM coordinates based on the $\mathrm{CaM}:\mathrm{M}\mathrm{13}$ complex (pdb entry 1cdl). In this calculation, the upper bounds of all observed intermolecular NOEs were set to 5 Å. CaM domains tr1c and tr2c are coloured green and grey respectively and the idoxifene molecules are coloured in pairs (blue, cyan, yellow, or beige) derived from single calculations. View B is orientated to coincide with parts C and D. Panels (c) and (d) show the positions of four molecules of idoxifene derived from a single NOE-restrained docking calculation to the tr2c domain of CaM (from pdb entry 1cll), illustrating one arrangement of four conformations that satisfy the NOE restraints. The four idoxifene molecules are shown in pairs for clarity only. The two darker-coloured idoxifene molecules have either the phenyl group (c) or the $p$ -iodo-phenyl group (d) by the pocket in the hydrophobic surface of the domain. The lighter-coloured molecules also satisfy NOEs that are within reach of the ligand-binding site associated with the tr1c domain. The surface representation of tr2c is coloured as follows: carbon (grey), nitrogen (blue), oxygen (red), and sulfur (yellow).