Crystallization and preliminary X-ray diffraction studies on cytosolic (class 1) aldehyde dehydrogenase from sheep liver.

The cytosolic (Class 1) aldehyde dehydrogenase (AlDH) from sheep liver has been crystallized in a form suitable for X-ray diffraction studies. The crystals, grown by vapour diffusion using 6.5 to 7.5% methoxypolyethylene glycol 5000 as precipitant, at pH 6.5, are orthorhombic with 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 to at least 2.8 A resolution. Although unmodified AlDH crystallized readily, a key factor in obtaining diffraction-quality crystals was the covalent attachment of an active site reporter group, provided by 3,4-dihydro-3-methyl-6-nitro-2H-1,3-benzoxazin-2-one.