Figure 3.

 Structural analysis of the apo (a) and the agonist-bound (b) forms of the T1R3 receptor. Representative structures display the conformations of residues N737^5.47, Y771^6.46, and W775^6.50. Red arrows suggest a putative activation mechanism. (c) Distribution of the inter-residue N737^5.47-Y771^6.46 and N737^5.47-W775^6.50 distances (1 and 2). Distribution of the Y771^6.46-W775^6.50 side-chain center-of-mass distances (3). Distances have been calculated between the O^δ1, O^η, and N^ε1 atoms of N737^5.47, Y771^6.46, and W775^6.50, respectively. Y771^6.46 center of mass has been calculated considering the aromatic ring including C^ε1, C^ε2, C^δ1, C^δ2, C^γ, and C^ζ atoms. W775^6.50 center of mass has been calculated considering the pyrrole ring including N^ε1, C^ε2, C^δ1, C^δ2, C^γ atoms. See Supplementary Figure 4 for time series plots.