Characterization of a Membrane-Associated Trimeric Low-pH-Induced Form of the Class II Viral Fusion Protein E from Tick-Borne Encephalitis Virus and Its Crystallization
Characterization of a Membrane-Associated Trimeric Low-pH-Induced Form of the Class II Viral Fusion Protein E from Tick-Borne Encephalitis Virus and Its Crystallization
复制标题
蜱传脑炎病毒 II 类病毒融合蛋白 E 膜相关三聚体低 pH 诱导形式的表征及其结晶
作者：
K. Stiasny;S. Bressanelli;J. Lepault;F. Rey;F. Heinz
摘要森林脑炎病毒囊膜蛋白E(Se二聚体)的二聚体无膜锚定形式与脂质体在酸性pH条件下相互作用，使其转化为膜插入型Se三聚体。电子显微镜显示，这些三聚体沿着三重分子轴有很长的尺寸，分子轴垂直于膜平面，蛋白质通过内部融合肽插入到膜平面。表面含Se的脂质体以紧密排列的方式显示蛋白质的晶状排列，其中每个三聚体被其他六个三聚体包围，这表明在插入过程中存在协同作用。用非离子去污剂增溶Se三聚体，得到了适合于X射线衍射分析的三维晶体。
ABSTRACT The interaction of a dimeric membrane anchor-free form of the envelope protein E (sE dimer) from tick-borne encephalitis virus with liposomes at acidic pH levels leads to its conversion into membrane-inserted sE trimers. Electron microscopy shows that these trimers have their long dimensions along the threefold molecular axis, which is oriented perpendicularly to the plane of the membrane, where the protein inserts via the internal fusion peptide. Liposomes containing sE at their surface display paracrystalline arrays of protein in a closely packing arrangement in which each trimer is surrounded by six others, suggesting cooperativity in the insertion process. sE trimers, solubilized with nonionic detergents, yielded three-dimensional crystals suitable for X-ray diffraction analysis.