Table 1.

Aligned α-carboxylate and α-amino VFT domain binding residues from a multiple sequence alignment of class C GPCRs

rmGlu-1	S165	T188	D208	Y236	D318
rmGlu-3	S151	T174	D194	Y222	D301
hCaR	S147	S170	D190	Y218	E297
mT1R1	T150	S173	D193	Y221	E302
mT1R3	S147	S170	D190	Y218	E301
mGPRC6A	S149	T172	D192	Y220	D303

Known α-amino and α-carboxylate binding residues from the crystal structures of the VFT domains of rat mGlu-1 (Kunishima et al., 2000) and rat mGlu-3 (Muto et al., 2007) are presented together with aligned residues for various L-amino acid binding members of GPCR class C including the human isoform of the CaR and mouse isoforms of T1R2, T1R3 and GPRC6A. The table has been modified (Conigrave and Hampson, 2006). The Protein Database accession numbers used in the analysis were as follows: NP_058707.1 (rmGlu-1), NP_001099182.1 (rmGlu-3), NP_000379.2 (hCaR), NP_114073.1 (mT1R1), NP_114078.1 (mT1R3), NP_694711.1 (mGPRC6A).

CaR, calcium-sensing receptor; GPCR, G-protein-coupled receptor; GPRC6A, G-protein-coupled receptor family C (class C) member 6A; mGlu, metabotropic glutamate receptor; VFT domain, Venus Fly Trap domain.