期刊
JOURNAL OF MOLECULAR BIOLOGY
卷 316, 期 3, 页码 657-666出版社
ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
DOI: 10.1006/jmbi.2001.5365
关键词
electron microscopy; image analysis; mitochondria; protein sorting; Saccharomyces cerevisiae
The mitochondrial outer membrane contains a multi-subunit machinery responsible for the specific recognition and translocation of precursor proteins. Dais translocase of the outer membrane (TOM) consists of three receptor proteins, Tom20, Tom22 and Tom70, the channel protein Tom40, and several small Tom proteins. Single-particle electron microscopy analysis of the Neurospora TOM complex has led to different views with two or three stain-filled centers resembling channels. Based on biochemical and electron microscopy studies of the TOM complex isolated from yeast mitochondria, we have discovered the molecular reason for the different number of channel-like structures. The TOM complex from wild-type yeast contains up to three stain-filled centers, while from a mutant yeast selectively lacking Tom20, the TOM complex particles contain only two channel-like structures. From mutant mitochondria lacking Tom22, native electrophoresis separates an similar to80 kDa subcomplex that consists of Tom40 only and is functional for accumulation of a precursor protein. We conclude that while Tom40 forms the import channels, the two receptors Tom22 and Tom20 are required for the organization of Tom40 dimers into larger TOM structures. (C) 2002 Elsevier Science Ltd.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据