Fig. 7: Residues involved in the substrate binding pocket through the acyl chains of PE.

a Residues that make up the N-Ret-PE binding site are indicated as purple sticks. Both acyl chains appear to be associated with L42 (TM1), I649 (TM2) I650 (TM2) and F1397 (loop between TM7 and ECD2) through hydrophobic interactions. The main chain of I649 interacts with the side chain of Y588 (ECD1 loop). b Closeup view of the residues involved in the acyl chain coordination.