A Structural Model of the Cytochrome c Reductase/Oxidase Supercomplex from Yeast Mitochondria

verfasst von
Jesco Heinemeyer, Hans Peter Braun, Egbert J. Boekema, Roman Kouřil
Abstract

Mitochondrial respiratory chain complexes are arranged in supercomplexes within the inner membrane. Interaction of cytochrome c reductase (complex III) and cytochrome c oxidase (complex IV) was investigated in Saccharomyces cerevisiae. Projection maps at 15 Å resolution of supercomplexes III 2 + IV1 and III2 + IV2 were obtained by electron microscopy. Based on a comparison of our maps with atomic x-ray structures for complexes III and IV we present a pseudo-atomic model of their precise interaction. Two complex IV monomers are specifically attached to dimeric complex III with their convex sides. The opposite sides, which represent the complex IV dimer interface in the x-ray structure, are open for complex IV-complex IV interactions. This could lead to oligomerization of III 2 + IV2 supercomplexes, but this was not detected. Instead, binding of cytochrome c to the supercomplexes was revealed. It was calculated that cytochrome c has to move less than 40Å at the surface of the supercomplex for electron transport between complex III2 and complex IV. Hence, the prime function of the supercomplex III2 + IV2 is proposed to be a scaffold for effective electron transport between complexes III and IV.

Organisationseinheit(en)
Institut für Pflanzengenetik
Externe Organisation(en)
Reichsuniversität Groningen
Typ
Artikel
Journal
Journal of Biological Chemistry
Band
282
Seiten
12240-12248
Anzahl der Seiten
9
ISSN
0021-9258
Publikationsdatum
23.04.2007
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Biochemie, Molekularbiologie, Zellbiologie
Elektronische Version(en)
https://doi.org/10.1074/jbc.M610545200 (Zugang: Offen)
https://doi.org/10.15488/11691 (Zugang: Offen)