McMahon S A, Leonard G A, Buchanan L V, Giraud M F, Naismith J H
Centre for Biomolecular Sciences, School of Biomedical Science, North Haugh, The University, St Andrews, Fife, KY16 9ST, Scotland.
Acta Crystallogr D Biol Crystallogr. 1999 Feb;55(Pt 2):399-402. doi: 10.1107/s0907444998010877.
UDP-galactopyranose mutase, the enzyme responsible for the conversion of UDP-galactopyranose to UDP-galactofuranose, has been crystallized in a form suitable for X-ray diffraction studies. UDP-galactofuranose is a key component of mycobacterial cell walls. Crystals of both the native protein and a selenomethionine variant have been grown by the vapour-diffusion method in hanging drops, and diffract to beyond 3.0 A using synchrotron radiation. Equilibration was against a solution of 20%(w/v) polyethylene glycol (4K), 12%(v/v) 2--propanol, 0.1 M HEPES pH 7.6 at 293.5 K. Crystals grow as thin plates of dimensions 0.4 x 0.2 x approximately 0.02 mm. They are monoclinic [corrected], space group P21, with unit-cell dimensions a = 71. 12, b = 58.42, c = 96.38 A, beta = 96.38 degrees. 92% (native) and 94% (selenomethionine) complete data sets have been recorded to 2.9 A (Rmerge = 5.0%) and 3.0 A (Rmerge = 6.9%), respectively. The Matthews coefficient is 2.35 A3 Da-1 for a dimer in the asymmetric unit, the solvent content being 47%. Diffraction data have also been recorded on a putative platinum derivative to 3.5 A.
UDP-吡喃半乳糖变位酶负责将UDP-吡喃半乳糖转化为UDP-呋喃半乳糖，已结晶成适合X射线衍射研究的形式。UDP-呋喃半乳糖是分枝杆菌细胞壁的关键成分。天然蛋白和硒代甲硫氨酸变体的晶体均通过悬滴气相扩散法生长，并使用同步辐射衍射至3.0 Å以上。在293.5 K下，平衡液为20%（w/v）聚乙二醇（4K）、12%（v/v）2-丙醇、0.1 M HEPES pH 7.6的溶液。晶体生长为尺寸为0.4×0.2×约0.02 mm的薄板。它们是单斜晶系[校正后]，空间群为P21，晶胞参数a = 71.12，b = 58.42，c = 96.38 Å，β = 96.38°。已分别收集到完整数据集，天然蛋白的为92%，分辨率为2.9 Å（Rmerge = 5.0%）；硒代甲硫氨酸变体的为94%，分辨率为3.0 Å（Rmerge = 6.9%）。非对称单元中一个二聚体的马修斯系数为2.35 Å3 Da-1，溶剂含量为47%。还记录了一种假定的铂衍生物至3.5 Å的衍射数据。
