Crystallization and preliminary X-ray studies on the hyperstable 3-isopropylmalate dehydrogenase from the thermoacidophilic archaeon Sulfolobus sp. strain 7

3-Isopropylmalate dehydrogenase from the thermoacidophilic archaeon, Sulfolobus sp. strain 7, has been crystallized by the vapor-diffusion method. The crystals were grown from a solution containing ammonium sulfate, 2-methyl-2,4-pentanediol and magnesium chloride. The crystallization requires 2-methyl-2,4-pentanediol to avoid twinning of the crystals. The crystal belongs to the orthorhombic system with the space group P222₁ and unit-cell dimensions a = 67.9, b = 93.3 and c = 134.1 Å.