Fig. 3: 3IMG recognition by GTR1.

a Structure of 3IMG bound to GTR1 in the inward-facing state. 3IMG is shown in ball and stick representation. The N-domain and C-domain are colored light blue and light pink, respectively. b Cut-open electrostatic potential surface of GTR1^3IMG, with 3IMG shown as sticks. The electrostatic potential surface was calculated using the APBS plug-in in PyMOL (red to blue, −60 kT/e to +60 kT/e). c EM density maps of 3IMG and interacting residues of GTR1. The densities of these residues and 3IMG are contoured at 4 σ and are shown as gray and green meshes, respectively. d, e Detailed interactions between GTR1 and the main backbone (d) and side chain (e) of 3IMG. The interacting residues of GTR1 and 3IMG are depicted as sticks. f GTL uptake by GTR1^WT and its variants with mutations in the substrate binding site. GFP-expressing cells served as controls. Data were normalized to the total cell number for each variant and are presented relative to GTR1^WT. The values are presented as the mean ± SEM of n = 4 independent replicates.