Pal G P, Jakob R, Hahn U, Bowien B, Saenger W
J Biol Chem. 1985 Sep 5;260(19):10768-70.
Ribulose-1,5-bisphosphate carboxylase-oxygenase (L8S8) from Alcaligenes eutrophus has been crystallized by equilibrium vapor diffusion techniques with ammonium sulfate as precipitant. Crystals thus obtained either as the ternary complex with CO2 and Mg2+ or as the quaternary complex with CO2, Mg2+, and 2-carboxyarabinitol 1,5-bisphosphate, a transition state analogue, diffract at least to 2.8-A resolution. Both are essentially isomorphous to each other, having orthorhombic space group C222(1) with cell dimensions a = 159 A, b = 159 A, and c = 200 A, and there is half a molecule in the asymmetric unit. The crystals of the ternary complex are sometimes twinned about the c axis so that the space group appears to be tetragonal. In this light, our earlier report (Bowien, B., Mayer, F., Spiess, E., Pähler, A., Englisch, U., and Saenger, W. (1982) Eur. J. Biochem. 106, 405-410) on a tetragonal space group P4(2)2(1)2 with crystals obtained from the same enzyme with Mg2+ and CO2 but without 2-carboxyarabinitol 1,5-bisphosphate might be incorrect.
从真养产碱杆菌中提取的1,5-二磷酸核酮糖羧化酶加氧酶（L8S8），已通过平衡气相扩散技术，以硫酸铵作为沉淀剂进行了结晶。由此获得的晶体，无论是与二氧化碳和镁离子形成的三元复合物，还是与二氧化碳、镁离子以及过渡态类似物2-羧基阿拉伯糖醇1,5-二磷酸形成的四元复合物，其衍射分辨率至少可达2.8埃。两者基本同晶型，属于正交空间群C222(1)，晶胞参数为a = 159埃，b = 159埃，c = 200埃，不对称单元中有半个分子。三元复合物的晶体有时会沿c轴孪晶，致使空间群看似为四方晶系。鉴于此，我们之前关于从相同酶与镁离子和二氧化碳但不含2-羧基阿拉伯糖醇1,5-二磷酸所获得的晶体属于四方空间群P4(2)2(1)2的报告（Bowien, B., Mayer, F., Spiess, E., Pähler, A., Englisch, U., and Saenger, W. (1982) Eur. J. Biochem. 106, 405 - 410）可能有误。
