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エンドウ トシヤ
ENDO TOSHIYA
遠藤 斗志也 所属 京都産業大学 生命科学部 先端生命科学科 職種 客員教授 |
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| 言語種別 | 英語 |
| 発行・発表の年月 | 2022/07 |
| 形態種別 | 研究論文 |
| 査読 | 査読あり |
| 招待論文 | 招待あり |
| 標題 | Structural overview of the translocase of the mitochondrial outer membrane complex |
| 執筆形態 | その他 |
| 掲載誌名 | Biophysics and Physicobiology |
| 掲載区分 | 国内 |
| 出版社・発行元 | Biophysical Society of Japan |
| 巻・号・頁 | 19,pp.n/a-n/a |
| 担当区分 | 責任著者 |
| 著者・共著者 | Yuhei Araiso,Toshiya Endo |
| 概要 | Most mitochondrial proteins are synthesized as precursor proteins (preproteins) in the cytosol and imported into mitochondria. The translocator of the outer membrane (TOM) complex functions as a main entry gate for the import of mitochondrial proteins. The TOM complex is a multi-subunit membrane protein complex composed of a β-barrel channel Tom40 and six single-pass membrane proteins. Recent cryo-EM studies have revealed high-resolution structures of the yeast and human TOM complexes, which enabled us to discuss the mechanism of protein import at an amino-acid residue level. The cryo-EM structures show that two Tom40 β-barrels are surrounded by two sets of small Tom subunits to form a dimeric structure. The intermembrane space (IMS) domains of Tom40, Tom22, and Tom7 form a binding site for presequence-containing preproteins in the middle of the dimer to achieve their efficient transfer of to the downstream translocase, the TIM23 complex. The N-terminal segment of Tom40 spans the channel from the cytosol to the IMS to interact with Tom5 at the periphery of the dimer, where downstream components of presequence-lacking preproteins are recruited. Structure-based biochemical analyses together with crosslinking experiments revealed that each Tom40 channel possesses two distinct paths and exit sites for protein translocation of different sets of mitochondrial preproteins. Here we summarize the current knowledge on the structural features, protein translocation mechanisms, and remaining questions for the TOM complexes, with particular emphasis on their determined cryo-EM structures. This article is an extended version of the Japanese article, Structural basis for protein translocation by the translocase of the outer mitochondrial membrane, published in SEIBUTSU BUTSURI Vol. 60, p. 280-283 (2020). |
| DOI | 10.2142/biophysico.bppb-v19.0022 |
| ISSN | /2189-4779 |
| PMID | 35859989 |
| PermalinkURL | https://www.jstage.jst.go.jp/article/biophysico/19/0/19_e190022/_pdf |