Table 2.

Mutagenesis-based data on critical residues for binding of selected ionophore ligands to TM2 domains of GABA-A receptor subunits (legend as in Fig. 1).

	Ligands							References
TM2 residue	P	PTZ	BPH	BL	PC	LA	NP *
2	yes	no	yes	no			yes	(I)
3	yes		yes					(I)
6	yes	yes		yes	yes **	no	yes	(II)
9	yes	no	no	no	no			(III)
15	yes							(IV)
19	yes							(IV)

^*E.g., dieldrin.

^**partially sensitive (border of the binding pocket?).

References: I (Gurley et al., 1995; Edwards and Lees, 1997; Jursky et al., 2000; Buhr et al., 2001), II (Sugimoto et al., 2002), III (Tierney et al., 1996; Lindquist et al., 2004), IV (Findlay et al., 2001; Dibas et al., 2002)