Mft52, an acid-bristle protein in the cytosol that delivers precursor proteins to yeast mitochondria.
We have identified a novel protein, Mft52, in the cytosol of yeast cells. Mft52 has a two-domain structure that includes a receptor-like carboxyl-terminal "acid-bristle" domain, which binds basic, amphipathic mitochondrial targeting sequences. Native Mft52, purified from the cytosol of yeast cells, is found as a large particle eluting in the void volume of a Superose 6 gel filtration column. Fusion proteins, consisting of mitochondrial targeting sequences fused to nonmitochondrial passenger proteins, are targeted to mitochondria in wild-type yeast cells, but defects in the gene encoding Mft52 drastically reduce the delivery of these proteins to the mitochondria. We propose that Mft52 is a subunit of a particle that is part of a system of targeting factors and molecular chaperones mediating the earliest stages of protein targeting to the mitochondria.
Cartwright
P
P
School of Biochemistry, La Trobe University, Bundoora 3083, Australia.
Beilharz
T
T
Hansen
P
P
Garrett
J
J
Lithgow
T
T
D000595:Amino Acid Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*
D002352:Carrier Proteins; D005656:Fungal Proteins; D011498:Protein Precursors