Arrangement of subunits in intact mammalian mitochondrial ATP synthase determined by cryo-EM.

TitleArrangement of subunits in intact mammalian mitochondrial ATP synthase determined by cryo-EM.
Publication TypeJournal Article
Year of Publication2012
AuthorsBaker, LA, Watt, IN, Runswick, MJ, Walker, JE, Rubinstein, JL
JournalProc Natl Acad Sci U S A
Date Published2012 Jul 17
KeywordsAnimals, Cattle, Cryoelectron Microscopy, Mitochondrial Proton-Translocating ATPases, Models, Molecular, Protein Conformation, Protein Subunits, Protons

Mitochondrial ATP synthase is responsible for the synthesis of ATP, a universal energy currency in cells. Whereas X-ray crystallography has revealed the structure of the soluble region of the complex and the membrane-intrinsic c-subunits, little is known about the structure of the six other proteins (a, b, f, A6L, e, and g) that comprise the membrane-bound region of the complex in animal mitochondria. Here, we present the structure of intact bovine mitochondrial ATP synthase at ∼18 Å resolution by electron cryomicroscopy of single particles in amorphous ice. The map reveals that the a-subunit and c(8)-ring of the complex interact with a small contact area and that the b-subunit spans the membrane without contacting the c(8)-ring. The e- and g-subunits extend from the a-subunit density distal to the c(8)-ring. The map was calculated from images of a preparation of the enzyme solubilized with the detergent dodecyl maltoside, which is visible in electron cryomicroscopy maps. The structure shows that the micelle surrounding the complex is curved. The observed bend in the micelle of the detergent-solubilized complex is consistent with previous electron tomography experiments and suggests that monomers of ATP synthase are sufficient to produce curvature in lipid bilayers.

Alternate JournalProc. Natl. Acad. Sci. U.S.A.
Citation Key10.1073/pnas.1204935109
PubMed ID22753497
PubMed Central IDPMC3406826
Grant ListMC_U105663150 / / Medical Research Council / United Kingdom
MOP 81294 / / Canadian Institutes of Health Research / Canada