Three-dimensional structure of ncd-decorated microtubules obtained by a back-projection method.
Three-dimensional structure of ncd-decorated microtubules obtained by a back-projection method.
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通过反投影法获得的 ncd 修饰微管的三维结构。
DOI：
10.1006/jmbi.1996.0434
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发表时间：
1996
影响因子：
5.6
通讯作者：
Milligan,RA
中科院分区：
文献类型：
--
作者：
Sosa,H;Milligan,RA
我们已经使用冷冻电子显微镜和图像分析，以获得三维（3D）结构的11，12，14和15个原丝微管与运动域的ncd装饰。为了获得3D地图，我们开发了一种不需要微管蛋白异二聚体螺旋排列的反投影方法。该方法允许计算3D图，即使当存在晶格不连续性（接缝）时。这些地图显示，我们研究的微管符合具有一个或多个接缝的B型晶格。在5′-腺苷酰亚胺-碘二磷酸（AMP-PNP）存在下，ncd的运动域与微管原丝嵴结合，仅与一条原丝相互作用。观察沿着微管轴的结构显示，ncd运动域和微管蛋白向相反的方向倾斜。我们确定微管蛋白亚基的顺时针倾斜对应于微管的负端朝向正端的视图。
We have used cryo-electron microscopy and image analysis to obtain the three-dimensional (3D) structure of 11, 12, 14 and 15 protofilament microtubules decorated with the motor domain of ncd. To obtain the 3D maps, we developed a back-projection method that does not require a helical arrangement of the tubulin heterodimers. This method allows the calculation of 3D maps even when lattice discontinuities (seams) are present. The maps show that the microtubules we studied conform to a B-type lattice with one or more seams. In the presence of 5′-adenylim-idodiphosphate (AMP-PNP), the motor domain of ncd binds to the microtubule protofilament crest interacting with only one protofilament. Viewing the structures along the microtubule axis shows that the ncd motor domain and the tubulin are tilted in opposite directions. We determined that a clockwise tilt of the tubulin subunits corresponds to a view from the minus end towards the plus end of the microtubule.