<p>(A) The N-terminal domain (NTD) of cT1R1 was expressed independently from the transmembrane heptahelical domain (HD), minus a short putative signal peptide (S), and a cysteine-rich region (CRR). (B) The pET28-cT1R1-NTD plasmid encodes a fusion protein that contains an N-terminal His-tag that can be cleaved with thrombin, followed by cT1R1-NTD (Leu21-Ser495) and a C-terminal His-tag. (C) Full-length cT1R1 is presented according to its primary amino acid sequence deduced from DNA sequence. The numerical positions of amino acid residues of cT1R1 are indicated.</p
