Zhao Yiwei, Li Zhong, Drozd Sandra, Guo Yi, Stack Robert, Hauer Charles, Li Hongmin
Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, New York 12201-0509, USA.
Acta Crystallogr D Biol Crystallogr. 2004 Feb;60(Pt 2):353-6. doi: 10.1107/S090744490302763X. Epub 2004 Jan 23.
Mycoplasma arthritidis-derived mitogen (MAM), a bacterial superantigen, has been crystallized in complex with its human receptor, major histocompatibility complex (MHC) class II antigen, by the hanging-drop vapor-diffusion method. Crystals were obtained under three conditions, with ammonium sulfate, phosphate salt and PEG 8000 as the precipitant. The crystals grown under these conditions all belong to space group I222, with the same unit-cell parameters: a = 137.4, b = 178.2, c = 179.6 A. Diffraction data were collected to 3.3 and 3.4 A resolution from crystals of native and selenomethionylated MAM-MHC complexes, respectively. Self- and cross-rotation function calculations suggest the presence of two complex molecules in the asymmetric unit, resulting in a V(M) of 4.0 and a solvent content of 69%. An interpretable electron-density map was produced using a combination of molecular replacement and SAD phasing.
关节炎支原体衍生丝裂原（MAM）是一种细菌超抗原，已通过悬滴气相扩散法与它的人类受体主要组织相容性复合体（MHC）II类抗原形成复合物并结晶。在三种条件下获得了晶体，分别以硫酸铵、磷酸盐和聚乙二醇8000作为沉淀剂。在这些条件下生长的晶体均属于空间群I222，具有相同的晶胞参数：a = 137.4，b = 178.2，c = 179.6 Å。分别从天然和硒代甲硫氨酸化的MAM-MHC复合物晶体收集到了分辨率为3.3 Å和3.4 Å的衍射数据。自身旋转函数和交叉旋转函数计算表明在不对称单元中存在两个复合物分子，V(M)为4.0，溶剂含量为69%。结合分子置换和单波长反常散射（SAD）相位法生成了可解释的电子密度图。
