Atomic structure of human TOM core complex
Open Access
- 29 September 2020
- journal article
- research article
- Published by Springer Science and Business Media LLC in Cell Discovery
- Vol. 6 (1), 1-10
- https://doi.org/10.1038/s41421-020-00198-2
Abstract
The translocase of the outer mitochondrial membrane (TOM) complex is the main entry gate for mitochondrial precursor proteins synthesized on cytosolic ribosomes. Here we report the single-particle cryo-electron microscopy (cryo-EM) structure of the dimeric human TOM core complex (TOM-CC). Two Tom40 beta-barrel proteins, connected by two Tom22 receptor subunits and one phospholipid, form the protein-conducting channels. The small Tom proteins Tom5, Tom6, and Tom7 surround the channel and have notable configurations. The distinct electrostatic features of the complex, including the pronounced negative interior and the positive regions at the periphery and center of the dimer on the intermembrane space (IMS) side, provide insight into the preprotein translocation mechanism. Further, two dimeric TOM complexes may associate to form tetramer in the shape of a parallelogram, offering a potential explanation into the unusual structural features of Tom subunits and a new perspective of viewing the import of mitochondrial proteins.This publication has 47 references indexed in Scilit:
- Mitochondrial protein import: from proteomics to functional mechanismsNature Reviews Molecular Cell Biology, 2010
- Importing Mitochondrial Proteins: Machineries and MechanismsCell, 2009
- Evolution of the Molecular Machines for Protein Import into MitochondriaScience, 2006
- Biogenesis of the Protein Import Channel Tom40 of the Mitochondrial Outer MembraneOnline Journal of Public Health Informatics, 2004
- The Protein Import Machinery of MitochondriaJournal of Biological Chemistry, 2004
- Machinery for protein sorting and assembly in the mitochondrial outer membraneNature, 2003
- Import and assembly of proteins into mitochondria of mammalian cellsBiochimica et Biophysica Acta (BBA) - Molecular Cell Research, 2002
- Protein Import Channel of the Outer Mitochondrial Membrane: a Highly Stable Tom40-Tom22 Core Structure Differentially Interacts with Preproteins, Small Tom Proteins, and Import ReceptorsMolecular and Cellular Biology, 2001
- Characterization of Rat TOM40, a Central Component of the Preprotein Translocase of the Mitochondrial Outer MembraneOnline Journal of Public Health Informatics, 2000
- Tom40 forms the hydrophilic channel of the mitochondrial import pore for preproteinsNature, 1998