8B4I

Cryo-EM structure of the Neurospora crassa TOM core complex at 3.3 angstrom

Summary for 8B4I

• Entry DOI: 10.2210/pdb8b4i/pdb
• EMDB information: 15849
• Descriptor: Mitochondrial import receptor subunit Tom40, Mitochondrial import receptor subunit Tom22, Translocase of outer mitochondrial membrane subunit 5, ... (7 entities in total)
• Functional Keywords: complex, outer membrane, mitochondria, membrane protein, tom, translocase, neurospora crassa
• Biological source: Neurospora crassa; More
• Total number of polymer chains: 10
• Total formula weight: 152330.21

Authors

Ornelas, P.,Kuehlbrandt, W. (deposition date: 2022-09-20, release date: 2023-08-09, Last modification date: 2023-08-30)

Primary citation

Ornelas, P.,Bausewein, T.,Martin, J.,Morgner, N.,Nussberger, S.,Kuhlbrandt, W.
Two conformations of the Tom20 preprotein receptor in the TOM holo complex.
Proc.Natl.Acad.Sci.USA, 120:e2301447120-e2301447120, 2023

PubMed Abstract: The TOM complex is the main entry point for precursor proteins (preproteins) into mitochondria. Preproteins containing targeting sequences are recognized by the TOM complex and imported into mitochondria. We have determined the structure of the TOM core complex from by single-particle electron cryomicroscopy at 3.3 Å resolution, showing its interaction with a bound preprotein at 4 Å resolution, and of the TOM holo complex including the Tom20 receptor at 6 to 7 Å resolution. TOM is a transmembrane complex consisting of two β-barrels, three receptor subunits, and three short transmembrane subunits. Tom20 has a transmembrane helix and a receptor domain on the cytoplasmic side. We propose that Tom20 acts as a dynamic gatekeeper, guiding preproteins into the pores of the TOM complex. We analyze the interactions of Tom20 with other TOM subunits, present insights into the structure of the TOM holo complex, and suggest a translocation mechanism.

PubMed: 37579144
DOI: 10.1073/pnas.2301447120

Experimental method

ELECTRON MICROSCOPY (3.32 Å)