Abstract In the past three decades, significant advances have been made in providing the biochemical background of TOM (translocase of the outer mitochondrial membrane)-mediated protein translocation into mitochondria. In the light of recent cryoelectron microscopy-derived structures of TOM isolated from Neurospora crassa and Saccharomyces cerevisiae, the interpretation of biochemical and biophysical studies of TOM-mediated protein transport into mitochondria now rests on a solid basis. In this review, we compare the subnanometer structure of N. crassa TOM core complex with that of yeast. Both structures reveal remarkably well-conserved symmetrical dimers of 10 membrane protein subunits. The structural data also validate predictions of weakly stable regions in the transmembrane β-barrel domains of the protein-conducting subunit Tom40, which signal the existence of β-strands located in interfaces of protein-protein interactions.

中文翻译：

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线粒体外膜中TOM核心复合物的结构

摘要 在过去的 30 年中，在提供 TOM（线粒体外膜转位酶）介导的蛋白质易位进入线粒体的生化背景方面取得了重大进展。根据最近从粗糙脉孢菌和酿酒酵母中分离出的低温电子显微镜衍生的 TOM 结构，对 TOM 介导的蛋白质转运到线粒体的生化和生物物理研究的解释现在建立在坚实的基础上。在这篇综述中，我们比较了粗糙脉孢菌 TOM 核心复合物与酵母的亚纳米结构。两种结构都显示出非常保守的 10 个膜蛋白亚基对称二聚体。结构数据还验证了对蛋白质传导亚基 Tom40 跨膜 β-桶结构域中弱稳定区域的预测，