Figure 5

Hydrophobic surface of 6 crystal structures of solute carrier transporters and the designed QTY variants. The native solute carrier transporters have many hydrophobic residues L, I, V and F in the transmembrane helices. After Q, T, and Y replacement of the L, I, V, F, the surfaces are much more hydrophilic. The hydrophobic surface (brownish) of the native transporters become more cyan color: (a) SLC2A1 versus SLC2A1QTY, (b) SLC7A11 versus SLC7A11QTY, (c) SLC4A4 versus SLC4A4QTY, (d) SLC1A5 versus SLC1A5QTY, (e) SLC7A5 versus SLC7A5QTY, (f) SLC29A1 versus SLC29A1QTY. The hydrophobic surface is largely reduced on the transmembrane helices for the QTY variants. These QTY variants converted to water-soluble form. For clarity, the N-terminus and C-terminus are deleted.