Figure 5.

Structural model of the 4F2hc-LAT2 heterodimeric complex based on the cryo-EM 3D-map. The model is shown from the extracellular side (A), the membrane plane (B), and the cytoplasmic side (C). The structure of 4F2hc-LAT2 is displayed as ribbon representation, and the structural elements of 4F2hc-ED (PDB ID code 2DH2) are colored as in Figure 4 (N-terminal region, red; TIM-barrel subdomain, cyan; C-terminal eight antiparallel β-strand subdomain, blue). Whereas the modeled TMD of 4F2hc is shown in magenta, the LAT2 homology model (LAT2^HM) is presented in orange. Individual atoms of the disulfide bridge between 4F2hc and LAT2 are shown as green spheres. In panel (B) the putative substrate entry side is represented by an L-Leu molecule (grey sticks) and an arrow.