Bauer A J, Rayment I, Frey P A, Holden H M
Institute for Enzyme Research, Graduate School, University of Wisconsin-Madison 53705.
Proteins. 1991;9(2):135-42. doi: 10.1002/prot.340090207.
Uridine diphosphogalactose-4-epimerase from E. coli has been crystallized in a form suitable for a high-resolution X-ray crystallographic structural analysis. The enzyme complexed with a substrate analogue, uridine diphosphobenzene (UDP-benzene), crystallizes readily using polyethylene glycol 8000 as the precipitant. The crystals belong to the orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions, a = 76.3 A, b = 83.1 A, and c = 132.1 A. Based on still setting photographs, the crystals diffract to a nominal resolution of 2.3 A and are stable in the X-ray beam. The enzyme used in these experiments was produced by a new expression system and a modified purification scheme.
来自大肠杆菌的尿苷二磷酸半乳糖-4-表异构酶已结晶成适合进行高分辨率X射线晶体学结构分析的形式。该酶与底物类似物尿苷二磷酸苯（UDP-苯）复合，使用聚乙二醇8000作为沉淀剂很容易结晶。晶体属于正交晶系空间群P2(1)2(1)2(1)，晶胞尺寸为a = 76.3 Å，b = 83.1 Å，c = 132.1 Å。根据静止放置照片，晶体衍射到名义分辨率为2.3 Å，并且在X射线束中稳定。这些实验中使用的酶是由新的表达系统和改进的纯化方案产生的。
