Crystallization and preliminary X-ray diffraction studies of homoserine dehydrogenase from Saccharomyces cerevisiae

Recombinant homoserine dehydrogenase from Saccharomyces cerevisiae has been crystallized in three different forms. Crystals of the apo-enzyme belong to the tetragonal space group P4 and have unit-cell-dimensions a = b = 130 and c = 240 Å. The resolution limit for these crystals is 3.9 Å. Crystals of homoserine dehydrogenase grown in the presence of the co-factor NAD⁺ have the tetragonal space group P4₁2₁2 or its enantiomorph P4₃2₁2. The unit-cell dimensions for these crystals are a = b = 80.4 and c = 250.2 Å, and the observed resolution limit is 2.2 Å. Protein crystals grown in the presence of the product L-homoserine and the inert NAD⁺ analogue 3-aminopyridine adenine dinucleotide belong to the monoclinic space group P2₁ with unit-cell parameters a = 58.8, b = 104.2, c = 120.7 Å, β = 91.9°. This last crystal form has a diffraction limit of 2.7 Å resolution.