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)