Crystallization and preliminary diffraction analysis of a truncated homodimer of human phenylalanine hydroxylase

A recombinant truncated form (delta1-102/delta428-452) of the non-heme iron-dependent metalloenzyme human phenylalanine hydroxylase (hPAH, phenylalanine 4-monooxygenase; EC 1.14.16.1) was expressed in E. coli, purified to homogeneity as a homodimer (70 kDa) and crystallized using the hanging drop vapour diffusion method. The crystals are orthorhombic, space group C222 with cell dimensions of a = 66.6 A, b = 108.4 A, c = 125.7 A. The calculated packing parameter (Vm) is 3.24 A3/Da with four 2-fold symmetric dimers (or eight momomers) in the unit cell. Data have been collected to 2.0 A resolution.