Fig. 2: Architecture of GTR1.

a Superposition of outward-facing and inward-facing states using the N-domain as a reference. The blue box indicates TM1. b Conformational shift in TM1 between the outward-facing and inward-facing states. c Magnified view of the interactions between TM1 and TM5 in the outward-facing and inward-facing states. The black dashed lines represent polar interactions, and the red arrows indicate the rotation of T85 and N88. d The inward-facing GTR1 structure is depicted as a cartoon model with lipids and the ICD in gray and light orange, respectively. The ICD is highlighted in a black box. e Lipids bind to the ICD. Lipids are depicted as gray sticks. The EM densities in this figure are shown as green meshes and contoured at 7 σ. f Magnified view of the interactions between TM7 and the ICD; the black dashed lines represent potential hydrogen bonds or salt bridges. g GTL uptake by GTR1^WT and the GTR1 mutants with alterations in TM7 and the intracellular interaction network. Cells expressing GFP 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.