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Molecular architecture of the active mitochondrial protein gate.

Authors :
Takuya Shiota
Kenichiro Imai
Jian Qiu
Hewitt, Victoria L.
Khershing Tan
Hsin-Hui Shen
Noriyuki Sakiyama
Yoshinori Fukasawa
Sikander Hayat
Megumi Kamiya
Arne Elofsson
Kentaro Tomii
Horton, Paul
Wiedemann, Nils
Pfanner, Nikolaus
Lithgow, Trevor
Toshiya Endo
Source :
Science. 9/25/2015, Vol. 349 Issue 6255, p1544-1548. 5p.
Publication Year :
2015

Abstract

Mitochondria fulfill central functions in cellular energetics,metabolism, and signaling.The outer membrane translocator complex (the TOM complex) imports most mitochondrial proteins, but its architecture is unknown. Using a cross-linking approach, we mapped the active translocator down to single amino acid residues, revealing different transport paths for preproteins through the Tom40 channel. An N-terminal segment of Tom40 passes from the cytosol through the channel to recruit chaperones from the intermembrane space that guide the transfer of hydrophobic preproteins.The translocator contains three Tom40 β-barrel channels sandwiched between a central α-helical Tom22 receptor cluster and external regulatory Tom proteins.The preprotein-translocating trimeric complex exchanges with a dimeric isoform to assemble new TOM complexes. Dynamic coupling of α-helical receptors, β-barrel channels, and chaperones generates a versatile machinery that transports about 1000 different proteins. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00368075
Volume :
349
Issue :
6255
Database :
Academic Search Index
Journal :
Science
Publication Type :
Academic Journal
Accession number :
109951375
Full Text :
https://doi.org/10.1126/science.aac6428