Two-dimensional crystals of cholera toxin B-subunit-receptor complexes: projected structure at 17-A resolution.
Two-dimensional crystals of cholera toxin B-subunit-receptor complexes: projected structure at 17-A resolution.
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霍乱毒素 B 亚基受体复合物的二维晶体：17-A 分辨率的投影结构。
DOI：
10.1073/pnas.83.22.8585
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发表时间：
1986
影响因子：
11.1
通讯作者：
Kornberg,RD
中科院分区：
文献类型：
--
作者：
Ludwig,DS;Ribi,HO;Schoolnik,GK;Kornberg,RD
当霍乱毒素的B亚单位与其膜受体神经节苷脂GM1结合时，在磷脂层中形成二维晶体。矩形晶格在负色下提供了分辨率为15-A的衍射，电子显微镜图像处理显示了一个由五个蛋白质密度组成的环。环的中心孔直径约为20A，外径约为60A。这些数据与平躺在膜表面的B亚基的五聚体、甜甜圈状结构一致。还得到了六方晶格，图像处理和化学交联的结果允许两种解释：B亚基可能以五聚体和六聚体的形式存在，或者更有可能的是，六方晶格可能代表无序或液晶形式，其中五聚体绕其5倍轴旋转平均。
The B subunit of cholera toxin forms two-dimensional crystals when bound to its membrane receptor, ganglioside GM1, in phospholipid layers. A rectangular crystal lattice gives diffraction extending to 15-A resolution in negative stain, and image-processing of electron micrographs reveals a ring of five protein densities. The diameter of the central hole and the outer diameter of the ring are about 20 and 60 A, respectively. These data are consistent with a pentameric, doughnut-shaped structure of the B subunit that lies flat on a membrane surface. A hexagonal crystal lattice is obtained as well, and results of image processing and chemical crosslinking allow two interpretations: the B subunit may exist in both pentameric and hexameric forms or, more likely, the hexagonal lattice may represent a disordered or liquid crystalline form, in which a pentamer undergoes rotational averaging about its 5-fold axis.