The active site of PRCP. (A) The active site of PRCP. The Asp-His-Ser catalytic triad is shown in salmon. Additional active site side chain features discussed in the text are colored according to structural element as in Figure 1. (B) Structural alignment of PRCP active site (blue), DPP4 (orange), and human pancreatic lipase (yellow) aligned on the catalytic histidine. PRCP residues are labeled.