Figure 1

Chemical structure of (A) xylitol and (B) sorbitol. (C) The T1R2 (pink) and T1R3 (green) monomers forming a heterodimeric STR, in which the portions of the VFD, CRD, and TMD are shaded by brown, black, and grey, respectively. The ligand-binding pockets for both the T1R2 and T1R3 monomers are represented by black circle.