Kryger G, Petsko G A, Ouyang J, Viola R E
Department of Chemistry, Rosenstiel Center, Brandeis University, Waltham, MA 02254-9110.
J Mol Biol. 1992 Nov 5;228(1):300-1. doi: 10.1016/0022-2836(92)90508-h.
Aspartate-beta-semialdehyde dehydrogenase catalyzes the NADPH-mediated reductive dephosphorylation of beta-aspartylphosphate at a branch point in the biosynthesis of several amino acids. The enzyme from Escherichia coli has been crystallized by the vapor diffusion method from Tris buffer (pH 8.5) using polyethylene glycol 4000 as a precipitant. The crystals are orthorhombic and have the symmetry of space group P222(1), with unit cell dimensions of a = 177.8 A, b = 59.9 A, c = 118.65 A, and alpha = beta = gamma = 90 degrees. The dimensions and space group are indicative of two enzyme dimers (40 kDa per subunit) in the asymmetric unit. The crystals show strong diffraction, and a native data set has been collected to 2.5 A resolution.
天冬氨酸-β-半醛脱氢酶在几种氨基酸的生物合成的一个分支点处催化β-天冬氨酰磷酸的NADPH介导的还原性去磷酸化反应。来自大肠杆菌的该酶已通过气相扩散法，以聚乙二醇4000作为沉淀剂，从Tris缓冲液（pH 8.5）中结晶出来。晶体为正交晶系，具有空间群P222(1)的对称性，晶胞参数为a = 177.8 Å，b = 59.9 Å，c = 118.65 Å，且α = β = γ = 90°。这些尺寸和空间群表明在不对称单元中有两个酶二聚体（每个亚基40 kDa）。晶体显示出强衍射，并且已收集到分辨率为2.5 Å的天然数据集。
