Figure 11: ERα in agonist or antagonist conformations. Helix 12 (green) is docked against AF-2 or displaced in agonist or antagonist structure, respectively. A) WT-ERα with genistein in pocket (PDB 2QA8). B) Y537S locks ERα in agonist conformation (PDB 1X7R) through altered hydrogen-bonding, burial of L536 sidechain and stabilization of H11-H12 loop by S537-D351 interaction. C) WT-ERα with raloxifene in the antagonist conformation (PDB 1ERR). D) L536S locks ERα in antagonist conformation (PDB 2QXS).