CRYSTALLIZATION OF GLYCEROL DEHYDROGENASE FROM BACILLUS-STEAROTHERMOPHILUS

The NAD(+)-linked glycerol dehydrogenase from Bacillus stearothermophi lus is a member of the so-called 'iron-containing' class of polyol deh ydrogenases. This enzyme has been crystallized in three different form s in the presence of a range of divalent cations and glycerol or NAD() using the hanging-drop method of vapour diffusion with ammonium sulf ate as the precipitant. X-ray photographs have established that the cr ystals 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) belo ng 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 cryst als grown with lead and glycerol (form C) belong to a primitive orthor hombic system with cell parameters a = 127, b = 178 and c = 173 Angstr om. Experiments using the synchrotron radiation source at the DRAL Dar esbury laboratory have shown all three crystal types diffract to at le ast 3 Angstrom resolution. Elucidation of the three-dimensional struct ure 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.