Mitochondrial protein import: precursor oxidation in a ternary complex with disulfide carrier and sulfhydryl oxidase.
The biogenesis of mitochondrial intermembrane space proteins depends on specific machinery that transfers disulfide bonds to precursor proteins. The machinery shares features with protein relays for disulfide bond formation in the bacterial periplasm and endoplasmic reticulum. A disulfide-generating enzyme/sulfhydryl oxidase oxidizes a disulfide carrier protein, which in turn transfers a disulfide to the substrate protein. Current views suggest that the disulfide carrier alternates between binding to the oxidase and the substrate. We have analyzed the cooperation of the disulfide relay components during import of precursors into mitochondria and identified a ternary complex of all three components. The ternary complex represents a transient and intermediate step in the oxidation of intermembrane space precursors, where the oxidase Erv1 promotes disulfide transfer to the precursor while both oxidase and precursor are associated with the disulfide carrier Mia40.
Institut für Biochemie und Molekularbiologie, Zentrum für Biochemie und Molekulare Zellforschung, Universität Freiburg, 79104 Freiburg, Germany.
Diana
D
Stojanovski
Dusanka
D
Milenkovic
Judith M
JM
Müller
Kipros
K
Gabriel
Agnes
A
Schulze-Specking
Michael J
MJ
Baker
Michael T
MT
Ryan
Bernard
B
Guiard
Nikolaus
N
Pfanner
Agnieszka
A
Chacinska
D004220:Disulfides / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism*; D009154:Mutation; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D050862:Oxidoreductases Acting on Sulfur Group Donors; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism*; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013379:Substrate Specificity
D004220:Disulfides; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D046912:Multiprotein Complexes; D010088:Oxidoreductases; D050862:Oxidoreductases Acting on Sulfur Group Donors; D011498:Protein Precursors; D029701:Saccharomyces cerevisiae Proteins; C495320:MIA40 protein, S cerevisiae; C073790:ERV1 protein, S cerevisiae