FIGURE 1.

Structural model of the GABA_AR α₁ and β₂ subunits. A, the extracellular binding domain is colored in white. Domains believed to contribute to the GABA transduction mechanism (Loop 2, Loop 7, M2-M3 linker, and pre-M1) are highlighted in yellow. The Loop C region of the GABA binding site is highlighted in green. The transmembrane domains (M1, M2, and M3) are colored in red. Residues in the pre-M1 region (Arg-216) as well as residues forming the potential PB/general anesthetic binding site (Asn-265 and Met-286) in the β₂ subunit and (Met-236) in the α₁ subunit are shown in a space-filled format. The M4 transmembrane helix has been omitted for illustration purposes. B, detailed view of the interface between the ligand binding domain and the transmembrane domain.