Homology modeling of PCFT. Homology models of PCFT based on the reported structures of the bovine and rat fructose transporters, Glut5, in the inward open and outward open conformations, respectively.^18,20  The 11th TMD with the Asn411 residue is highlighted. The predicted structure in the inward open configuration is indicated in blue. The predicted structure in the outward open conformation is indicated in green. (Left) A planar view of the protein. (Right) A view from the extracellular compartment into the aqueous translocation pathway. The Asn411 residue protrudes into the aqueous pathway and shifts further into the pathway when the protein is in the inward open conformation.