CRYSTALLIZATION OF GLYCEROL DEHYDROGENASE FROM BACILLUS-STEAROTHERMOPHILUS

The NAD(+)-linked glycerol dehydrogenase from Bacillus stearothermophilus is a member of the so-called 'iron-containing' class of polyol dehydrogenases. This enzyme has been crystallized in three different forms in the presence of a range of divalent cations and glycerol or NAD(+) using the hanging-drop method of vapour diffusion with ammonium sulfate as the precipitant. X-ray photographs have established that the crystals grown in the presence of zinc and glycerol (form A) most likely belong to space group I4(1)22 with cell. parameters a = b = 102 and c = 728 Angstrom. The crystals grown with zinc and NAD(+) (form B) belong to the tetragonal system and probably belong to the space group P42(1)2 with cell. parameters a = b = 150 and c = 220 Angstrom. The crystals grown with lead and glycerol (form C) belong to a primitive orthorhombic system with cell parameters a = 127, b = 178 and c = 173 Angstrom. Experiments using the synchrotron radiation source at the DRAL Daresbury laboratory have shown all three crystal types diffract to at least 3 Angstrom resolution. Elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this class of polyol dehydrogenases, which are not represented in the database at present, and enable comparisons to be made with enzymes belonging to the other classes.