McGonigle I , Lummis SC .

081925 Wellcome Trust , Medical Research Council , Wellcome Trust , WT081925 Wellcome Trust

	Figure 1. (A) RDL extracellular domain dimer. Extracellular loops A−F that form the agonist binding site region in related Cys-loop receptors are labeled. (B) Sequence alignment of extracellular domains of RDL and homologous Cys-loop receptor subunits (human GABAA α1, human GABAA β2, mouse 5-HT3A, and AChBP).
	Figure 2. (A) Electrophysiological traces showing maximal currents elicited by agonists tested at RDL receptors: GABA (100 μM), TACA (300 μM), isoguvacine (600 μM), β-alanine (10 mM), and taurine (10 mM). (B) Concentration response curves showing responses elicited by GABA and analogues at wild-type RDL receptors expressed in Xenopus oocytes: muscimol > GABA > TACA > isoguvacine > THIP > 5-AV > β-alanine > taurine. Data are means ± SEM; n ≥ 3.
	Figure 3. Chemical structures of GABA analogues examined in this study.
	Figure 4. Docking of GABA and active analogues (β-alanine, TACA, 5-AV, taurine, isoguvacine, muscimol, and THIP) into the RDL binding site. Analogues docked with the ammonium group located deep in the cleft formed between loop B and loop C aromatic residues. The carboxylate moiety or equivalent substituent was predicted to be located facing toward Arg111.

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