Cryo-EM Structure of the TOM Core Complex from Neurospora crassa

Thomas Bausewein; Deryck J Mills; Julian D Langer; Beate Nitschke; Stephan Nussberger; Werner Kühlbrandt

doi:10.1016/j.cell.2017.07.012

Cryo-EM Structure of the TOM Core Complex from Neurospora crassa

Cell. 2017 Aug 10;170(4):693-700.e7. doi: 10.1016/j.cell.2017.07.012.

Authors

Thomas Bausewein¹, Deryck J Mills¹, Julian D Langer², Beate Nitschke³, Stephan Nussberger³, Werner Kühlbrandt⁴

Affiliations

¹ Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany.
² Department of Molecular Membrane Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany.
³ Abt. Biophysik, Institut für Biomaterialien und biomolekulare Systeme, Universität Stuttgart, Pfaffenwaldring 57, 70550 Stuttgart, Germany.
⁴ Department of Structural Biology, Max-Planck-Institute of Biophysics, Max-von-Laue-Str. 3, 60438 Frankfurt am Main, Germany. Electronic address: werner.kuehlbrandt@biophys.mpg.de.

PMID: 28802041
DOI: 10.1016/j.cell.2017.07.012

Abstract

The TOM complex is the main entry gate for protein precursors from the cytosol into mitochondria. We have determined the structure of the TOM core complex by cryoelectron microscopy (cryo-EM). The complex is a 148 kDa symmetrical dimer of ten membrane protein subunits that create a shallow funnel on the cytoplasmic membrane surface. In the core of the dimer, the β-barrels of the Tom40 pore form two identical preprotein conduits. Each Tom40 pore is surrounded by the transmembrane segments of the α-helical subunits Tom5, Tom6, and Tom7. Tom22, the central preprotein receptor, connects the two Tom40 pores at the dimer interface. Our structure offers detailed insights into the molecular architecture of the mitochondrial preprotein import machinery.

Keywords: TOM complex; cryo-EM; mitochondria; protein import.

MeSH terms

Amino Acid Sequence
Carrier Proteins / chemistry*
Carrier Proteins / genetics
Carrier Proteins / ultrastructure
Cryoelectron Microscopy
Fungal Proteins / chemistry*
Fungal Proteins / genetics
Fungal Proteins / ultrastructure
Mass Spectrometry
Mitochondrial Membrane Transport Proteins / chemistry
Mitochondrial Membrane Transport Proteins / genetics
Mitochondrial Membrane Transport Proteins / ultrastructure
Mitochondrial Membranes / enzymology
Mitochondrial Precursor Protein Import Complex Proteins
Models, Molecular
Neurospora crassa / enzymology*
Protein Conformation, beta-Strand
Protein Translocation Systems / chemistry*
Protein Translocation Systems / genetics
Protein Translocation Systems / ultrastructure
Saccharomyces cerevisiae Proteins / chemistry

Substances

Carrier Proteins
Fungal Proteins
Mitochondrial Membrane Transport Proteins
Mitochondrial Precursor Protein Import Complex Proteins
Protein Translocation Systems
Saccharomyces cerevisiae Proteins