Two conformations of the Tom20 preprotein receptor in the TOM holo complex.
Proc Natl Acad Sci U S A
; 120(34): e2301447120, 2023 08 22.
Article
em En
| MEDLINE
| ID: mdl-37579144
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 Neurospora crassa 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 ß-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.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Saccharomyces cerevisiae
/
Proteínas do Complexo de Importação de Proteína Precursora Mitocondrial
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article