The TOM core complex: the general protein import pore of the outer membrane of mitochondria.
The TOM core complex: the general protein import pore of the outer membrane of mitochondria.
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DOI：
10.1083/jcb.147.5.959
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发表时间：
1999-11-29
影响因子：
7.8
通讯作者：
Nussberger, S
中科院分区：
文献类型：
--
作者：
Ahting, U;Thun, C;Hegerl, R;Typke, D;Nargang, F E;Neupert, W;Nussberger, S
核编码的前蛋白跨线粒体外膜的转运是由多组分的跨膜TOM复合体介导的。我们用洗涤剂十二烷基麦芽糖苷从分离的TOM全菌复合体中去除了受体Tom70和Tom20，从而分离出粗糙脉孢菌的TOM核心复合体。它由Tom40、Tom22和小的Tom组件Tom6和Tom7组成。用十二烷基麦芽糖苷增溶后，该核心复合体也可直接从线粒体中纯化。TOM核心复合体具有一般插入孔的特征；它包含高电导通道，并以靶向序列依赖的方式结合前蛋白。与全息复合体相比，它形成了一个双环结构，缺乏后一种粒子中看到的第三种密度。电子断层扫描的三维重建显示，有两个开放的孔穿过该复合体，直径为∼2.1 nm，高度为∼7 nm。Tom40是TOM核心复合体的关键结构元件。
Translocation of nuclear-encoded preproteins across the outer membrane of mitochondria is mediated by the multicomponent transmembrane TOM complex. We have isolated the TOM core complex of Neurospora crassa by removing the receptors Tom70 and Tom20 from the isolated TOM holo complex by treatment with the detergent dodecyl maltoside. It consists of Tom40, Tom22, and the small Tom components, Tom6 and Tom7. This core complex was also purified directly from mitochondria after solubilization with dodecyl maltoside. The TOM core complex has the characteristics of the general insertion pore; it contains high-conductance channels and binds preprotein in a targeting sequence-dependent manner. It forms a double ring structure that, in contrast to the holo complex, lacks the third density seen in the latter particles. Three-dimensional reconstruction by electron tomography exhibits two open pores traversing the complex with a diameter of ∼2.1 nm and a height of ∼7 nm. Tom40 is the key structural element of the TOM core complex.