... effects. In the binary complex, the binding of the cofactor at the active site results in the formation of stabilizing hydrogen bonds between the dihydroxypropyl side-chain and the carbonyl oxygen of Ser23 ... define the position, orientation, conformation and hydrogen bondingnetwork of the pterin cofactor in the three structures.Superpositions of the binary and ternary complexes of hPAH onto the crystal ... detailed picture of the protein contacts involved in the active site binding of the pterin cofactor [18,20,21], dopamine inhibitor [17] andL-Phe [21]. Thus, the superposition of the hPAH catalyticcore...