Structure of yeast cytochrome c oxidase in a supercomplex with cytochrome bc1

DOI: 10.1038/s41594-018-0172-z

Authors: Andrew M. Hartley (Birkbeck College, London) , Natalya Lukoyanova (Birkbeck College, London) , Yunyi Zhang (University College London) , Alfredo Cabrera-orefice (Radboud University Medical Center) , Susanne Arnold (Radboud University Medical Center) , Brigitte Meunier (Université Paris-Saclay) , Nikos Pinotsis (Birkbeck College, University of London) , Amandine Marechal (Birkbeck, University of London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Structural & Molecular Biology , VOL 26 , PAGES 78 - 83

State: Published (Approved)
Published: December 2018
Diamond Proposal Number(s): 14704

Abstract: Cytochrome c oxidase (complex IV, CIV) is known in mammals to exist independently or in association with other respiratory proteins to form supercomplexes (SCs). In Saccharomyces cerevisiae, CIV is found solely in an SC with cytochrome bc1 (complex III, CIII). Here, we present the cryogenic electron microscopy (cryo-EM) structure of S. cerevisiae CIV in a III2IV2 SC at 3.3 Å resolution. While overall similarity to mammalian homologs is high, we found notable differences in the supernumerary subunits Cox26 and Cox13; the latter exhibits a unique arrangement that precludes CIV dimerization as seen in bovine. A conformational shift in the matrix domain of Cox5A—involved in allosteric inhibition by ATP—may arise from its association with CIII. The CIII–CIV arrangement highlights a conserved interaction interface of CIII, albeit one occupied by complex I in mammalian respirasomes. We discuss our findings in the context of the potential impact of SC formation on CIV regulation.

Journal Keywords: Cryoelectron microscopy; Oxidoreductases

Subject Areas: Biology and Bio-materials

Diamond Offline Facilities: Electron Bio-Imaging Centre (eBIC)
Instruments: Krios II-Titan Krios II at Diamond