title: Specific recognition of mitochondrial preproteins by the cytosolic domain of the import receptor MOM72.
abstract: The import receptor MOM72 constitutes part of the protein translocation machinery of the outer mitochondrial membrane, the receptor-general insertion pore complex. The protein contains a membrane anchor at the NH2 terminus and a large cytosolic domain. In yeast and Neurospora crassa the cytosolic domain comprises about 570-580 amino acid residues. The cytosolic domain of yeast MOM72 was purified after expression in Escherichia coli as a homogeneous monomeric protein. It can recognize precursor proteins as demonstrated by its ability to compete for binding and import into the mitochondria and to physically interact with preproteins. A subset of preproteins including the ADP/ATP carrier and the phosphate carrier interact with very high affinity, precursors that are known to be targeted via MOM72. Thus, the cytosolic domain of MOM72 plays a critical function in the recognition of preproteins by directly binding to precursor proteins and thereby facilitating their targeting to mitochondria.
authors.affiliation: Institut für Physiologische Chemie, Universität München, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Schlossmann
authors.forename: K
authors.initials: K
authors.lastname: Dietmeier
authors.forename: N
authors.initials: N
authors.lastname: Pfanner
authors.forename: W
authors.initials: W
authors.lastname: Neupert
mesh_terms: D001483:Base Sequence; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D017931:DNA Primers; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D005656:Fungal Proteins; D007700:Kinetics; D008565:Membrane Proteins; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009492:Neurospora crassa / Q000378:metabolism*; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D015183:Restriction Mapping
chemical_list: D017931:DNA Primers; D005656:Fungal Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D011498:Protein Precursors; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D017886:Durapatite