CRYSTALLIZATION AND PRELIMINARY-X-RAY DIFFRACTION STUDIES ON CYTOSOLIC (CLASS-1) ALDEHYDE DEHYDROGENASE FROM SHEEP LIVER

The cytosolic (Class 1) aldehyde dehydrogenase (AIDH) from sheep liver has been crystallized in a form suitable for X-ray diffraction studie s. The crystals, grown by vapour diffusion using 6.5 to 7.5% methoxypo lyethylene glycol 5000 as precipitant, at pH 6.5, are orthorhombic wit h cell dimensions a = 80.7, b = 92.5, c = 151.6 a, space-group P2(1)2( 1)2(1), and one dimer in the asymmetric unit;. The crystals diffract t o at least 2.8 Angstrom resolution. Although unmodified AIDH crystalli zed readily, a key factor in obtaining diffraction-quality crystals wa s the covalent attachment of an active site reporter group, provided b y -dihydro-3-methyl-6-nitro-2H-1,3-benzoxazin-2-one.