Detailed views of the SNX5-IncE interface are shown in Figure 4C, D and E. Aside from main-chain hydrogen bonding to form the extended β-sheet, IncE engages in several critical side-chain interactions with the relatively hydrophobic SNX5 binding groove. At the N-terminus of the βA strand Val114 of IncE inserts into a pocket formed primarily by Tyr132 and Phe136 on the SNX5 α’’ helix (Figure 4C). A major contribution comes from IncE Phe116, with π-stacking occurring with the Phe136 side-chain and hydrophobic docking with Val140 of SNX5 (Figure 4D). Adjacent to IncE Phe116 at the end of the βA strand Lys118 makes an electrostatic contact with SNX5 Glu144. Finally, at the C-terminal end of the IncE βB strand Val127 and Leu129 contact an extended SNX5 surface composed of Leu133, Tyr132 and Met106 (Figure 4E).