CRYSTALLIZATION AND PRELIMINARY DIFFRACTION ANALYSIS OF A TRUNCATED HOMODIMER OF HUMAN PHENYLALANINE-HYDROXYLASE

A recombinant truncated form (Delta 1-102/Delta 428-452) of the non-he me 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 usi ng the hanging drop vapour diffusion method, The crystals are orthorho mbic, space group C222 with cell. dimensions of a=66.6 Angstrom, b=108 .4 Angstrom, c=125.7 Angstrom. The calculated packing parameter (V-m) is 3.24 Angstrom(3)/Da with four 2-fold symmetric dimers (or eight mom omers) in the unit cell, Data have been collected to 2.0 Angstrom reso lution. (C) 1997 Federation of European Biochemical Societies.