title: The structure of precursor proteins during import into mitochondria.
abstract: Precursor proteins must be at least partially unfolded during import into mitochondria, but their actual conformation during translocation is not known. Are proteins fully unfolded and threaded through the import machinery amino acid by amino acid, or do they retain some partial structure? The folding pathway of most proteins in vitro contains a partially folded intermediate known as the molten globule state, and it has been suggested that proteins are in the molten globule state during translocation across membranes. Here we show that precursors are normally fully unfolded during import into mitochondria. However, precursors containing residual structure can be imported, if less efficiently.
authors.affiliation: Department of Biochemistry, Molecular Biology, and Cell Biology, Northwestern University, Evanston, Illinois 60208-3500, USA.
authors.forename: M P
authors.initials: MP
authors.lastname: Schwartz
authors.forename: S
authors.initials: S
authors.lastname: Huang
authors.forename: A
authors.initials: A
authors.lastname: Matouschek
mesh_terms: D001692:Biological Transport; D007425:Intracellular Membranes / Q000378:metabolism; D007700:Kinetics; D008928:Mitochondria / Q000378:metabolism*; D011487:Protein Conformation; D017510:Protein Folding; D011498:Protein Precursors / Q000737:chemistry* / Q000378:metabolism
chemical_list: D011498:Protein Precursors