Structure of the γ-tubulin ring complex:: a template for microtubule nucleation
Structure of the γ-tubulin ring complex:: a template for microtubule nucleation
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DOI：
10.1038/35014058
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发表时间：
2000-06-01
影响因子：
21.3
通讯作者：
Agard, DA
中科院分区：
文献类型：
--
作者：
Moritz, M;Braunfeld, MB;Agard, DA
γ-微管蛋白环复合体是一种相对分子质量为-2.2x10(6)的蛋白质复合体，它在中心体形成微管。在这里，我们使用电子显微镜断层扫描和金属阴影来检查分离的果蝇伽马体和由伽马体和中心体成核的微管末端的结构。我们发现，伽马TURC是一种类似锁垫圈的结构，由重复的亚单位组成，顶部不对称地覆盖着一个盖子。从孤立的伽马巨噬细胞和中心体中生长的微管的一端也可以看到类似的帽环。针对伽马微管蛋白的抗体标记中心体中的微管末端，但不标记微管的壁。这些数据与模板介导的微管成核机制是一致的。
The gamma-tubulin ring complex (gamma TuRC) is a protein complex of relative molecular mass -2.2x10(6) that nucleates microtubules at the centrosome. Here we use electron-microscopic tomography and metal shadowing to examine the structure of isolated Drosophila gamma TuRCs and the ends of microtubules nucleated by gamma TuRCs and by centrosomes. We show that the gamma TuRC is a lockwasher-like structure made up of repeating subunits, topped asymmetrically with a cap. A similar capped ring is also visible at one end of microtubules grown from isolated gamma TuRCs and from centrosomes. Antibodies against gamma-tubulin label microtubule ends, but not walls, in centrosomes. These data are consistent with a template-mediated mechanism for microtubule nucleation by the gamma TuRC.