Figure 3.

ACP Binding to Human PPT

(A) Ribbon model of human PPT (green/red) with ACP (light brown). The mutated Ser→Ala acceptor residue of ACP is indicated in stick representation (arrow).

(B) Detailed PPT-ACP interactions. ACP is shown as light brown ribbon model with interacting residue side chains (labeled in blue). PPT residues are depicted as stick models (labeled in black).

(C and D) Local electrostatic potential of the α2 (recognition) helices of human ACP (C) and E. coli ACP (D), calculated with the REBEL module implemented in the ICM software package [36]. Red color indicates negative charge, blue color positive charges, ranging from −5 to +5 kcal/e.u. charge units. The Ser acceptor positions are depicted at the lower left corner of the ACP molecule. Arrows indicate positions of the hydrophobic recognition patches.