Fig. 4.

Bisphenol binding promotes ERα structural dynamics. (A) Differential interactions of bisphenols and E₂ with G521 and H524. (B) The interaction of E₂ with L525 strengthens a van der Waals interactions network involving T347 (H3), L525 (H11), and L536 (L11–L12). (C) Because of a lack of contact with BPA, L525 is not stabilized and adopts two different conformations. (D) In the BPC-bound ERα structure, T347 rotates by 180° to form a hydrogen bond with the bisphenol, resulting in the disruption of the hydrophobic network. (E) Ribbon representation of ERα LBD in complex with E₂ (red), BPA (green), BPAF (blue), and BPC (purple; dashed line denotes missing residues). Ligands are shown in yellow. The diameter of the ribbon is directly proportional to the temperature factor B and highlights the dynamics all along the polypeptide chain.