Three-dimensional structure of a double apoptosome formed by the Drosophila Apaf-1 related killer
Three-dimensional structure of a double apoptosome formed by the Drosophila Apaf-1 related killer
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DOI：
10.1016/j.jmb.2005.10.040
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发表时间：
2006-01-20
影响因子：
5.6
通讯作者：
Akey, CW
中科院分区：
文献类型：
--
作者：
Yu, XC;Wang, L;Akey, CW
果蝇Apaf-1相关的杀伤细胞（Dark）形成一个能激活Dronc（一种内源性细胞死亡途径中的顶端半胱氨酸蛋白酶原）的核糖体。为了研究这个过程，我们在dATP的存在下组装了一个大的Dark复合物。值得注意的是，我们发现细胞色素c不是组装所需的，并且当添加细胞色素c时，细胞色素c不与Dark复合物结合。然后，我们确定了一个3D结构的黑暗复杂的18.8埃分辨率使用电子冷冻显微镜和单粒子方法。在这个结构中，八个黑暗亚基形成了一个轮状粒子，其中两个环面对面。相比之下，Apaf-1形成由七个亚基组成的单环，每个Apaf-1结合细胞色素c分子。然后，我们使用相关的晶体结构来模拟Dark复合物。这项分析表明，一个单一的暗环和Apaf-1染色体共享许多关键特征。综合起来，这些数据表明，Dark复合体中的一个环可能代表果蝇的染色体。因此，我们的分析提供了这个复杂的域模型，并深入了解其功能。(c)2005爱思唯尔有限公司保留所有权利。
The Drosophila Apaf-1 related killer (Dark) forms an apoptosome that activates Dronc, an apical procaspase in the intrinsic cell death pathway. To study this process, we assembled a large Dark complex in the presence of dATP. Remarkably, we found that cytochrome c was not required for assembly and when added, cytochrome c did not bind to the Dark complex. We then determined a 3D structure of the Dark complex at 18.8 angstrom resolution using electron cryo-microscopy and single particle methods. In the structure, eight Dark subunits form a wheel-like particle and two of these rings associate face-to-face. In contrast, Apaf-1 forms a single ring that is comprised of seven subunits and each Apaf-1 binds a molecule of cytochrome c. We then used relevant crystal structures to model the Dark complex. This analysis shows that a single Dark ring and the Apaf-1 apoptosome share many key features. When taken together, the data suggest that a single ring in the Dark complex may represent the Drosophila apoptosome. Thus, our analysis provides a domain model of this complex and gives insights into its function. (c) 2005 Elsevier Ltd. All rights reserved.