Two conformations of the Tom20 preprotein receptor in the TOM holo complex

  • The TOM complex is the main entry point for precursor proteins into mitochondria. Precursor proteins containing targeting sequences are recognized by the TOM complex and imported into the mitochondria. We have determined the structure of the TOM core complex from Neurospora crassa by single-particle cryoEM at 3.3 Å resolution, showing its interaction with a bound presequence at 4 Å resolution, and of the TOM holo complex including the Tom20 receptor at 6-7 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 precursor proteins 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.

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Author:Pamela OrnelasORCiD, Thomas BauseweinGND, Janosch MartinGND, Nina MorgnerORCiDGND, Stephan NußbergerORCiDGND, Werner KühlbrandtORCiDGND
Parent Title (English):bioRxiv
Document Type:Preprint
Date of Publication (online):2023/01/26
Date of first Publication:2023/01/26
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2023/07/19
Page Number:17
Institutes:Biochemie, Chemie und Pharmazie / Biochemie und Chemie
Angeschlossene und kooperierende Institutionen / MPI für Biophysik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie
Licence (German):License LogoCreative Commons - CC BY-NC - Namensnennung - Nicht kommerziell 4.0 International