Figure 12. Molecular model of the interaction of PCCP⁻ with GABA_A receptors.

A, The side view of the PCCP⁻ docking pose from the perspective of the γ₂ subunit. The ligand and the mutated residues of the α₁ subunit, which have an impact on the affinity of the ligand, are shown in space filling representation. The 2′ valines of the α₁ subunit are rendered grey; the 6′ threonines of the α₁ subunit in green. The GABA_A receptor is displayed in ribbon representation with α₁ subunits shown in yellow, β₂ subunits in red, γ₂ subunit in blue. The complete transmembrane domain (TMD) is shown only of the α₁ and the β₂ subunits in the back. Of the subunits in front, only a segment of the transmembrane domain 2 (TMD2) is depicted. The TMD2 of the γ₂ subunit is only partly displayed to provide a “window” through which the ligand is seen. B, Top view of the pose showing the symmetric molecular interactions between ligand and receptor. PCCP⁻ (space filling) forms H-bonds (blue dashed lines) to the –OH groups of the 6′ threonines (stick representation) of each of the five subunits.