EVIDENCE FOR A MIXED LATTICE IN MICROTUBULES REASSEMBLED INVITRO
EVIDENCE FOR A MIXED LATTICE IN MICROTUBULES REASSEMBLED INVITRO
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DOI：
10.1016/0022-2836(80)90300-9
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发表时间：
1980-01-01
影响因子：
5.6
通讯作者：
EDELSTEIN, SJ
中科院分区：
文献类型：
--
作者：
MCEWEN, B;EDELSTEIN, SJ
[猪脑]微管组装在体外进行了广泛的结构分析，使用EM结合基于傅立叶变换和螺旋衍射理论的计算机分析。体外组装的微管显示12-16个原丝，其中14个最丰富（在一个大样本中占84%）。在几乎所有观察到的结构中，原丝是交错的，形成一个特征性的3-start浅螺旋。通过纤维倾斜实验证实了3-起始螺旋的存在，以校正微管扁平化的影响。因为α。和β微管蛋白亚基沿着原丝交替排列，连续的螺旋晶格可以通过相邻原丝之间的相互作用构建，包括不同的亚基（A型晶格）或相似的亚基（B型晶格）。14-原丝，3-起始微管与A或B型连续螺旋晶格不相容。提出的证据表明，晶格不连续性是存在的A和B类型的生成功能，后者占主导地位。
An extensive structural analysis of [pig brain] microtubules assembled in vitro was carried out using EM in conjunction with computer analysis based on Fourier transforms and helical diffraction theory. Microtubules assembled in vitro displayed 12-16 protofilaments, with 14 the most abundant (84% in one large sampling). In almost all structures observed, protofilaments are staggered to form a characteristic 3-start shallow helix. The presence of the 3-start helix was confirmed by fiber tilting experiments to correct the effects of microtubule flattening. Since .alpha. and .beta. tubulin subunits alternate along the protofilaments, continuous helical lattices can be constructed with interactions between adjacent protofilaments involving unlike subunits (type A lattice) or like subunits (type B lattice). The 14-protofilament, 3-start microtubules are incompatible with either the A or B type continuous helical lattice. Evidence is presented which indicates that lattice discontinuities are present which generate features of the A and B types, with the latter predominating.