Journal ArticleDOI
The ATP synthase: the understood, the uncertain and the unknown
TLDR
Evidence is growing for other roles of ATP synthases in the inner membranes of mitochondria, where they form supermolecular complexes, possibly with specific lipids, and these complexes probably contribute to, or even determine, the formation of the cristae.Abstract:
The ATP synthases are multiprotein complexes found in the energy-transducing membranes of bacteria, chloroplasts and mitochondria. They employ a transmembrane protonmotive force, Δ p , as a source of energy to drive a mechanical rotary mechanism that leads to the chemical synthesis of ATP from ADP and P i . Their overall architecture, organization and mechanistic principles are mostly well established, but other features are less well understood. For example, ATP synthases from bacteria, mitochondria and chloroplasts differ in the mechanisms of regulation of their activity, and the molecular bases of these different mechanisms and their physiological roles are only just beginning to emerge. Another crucial feature lacking a molecular description is how rotation driven by Δ p is generated, and how rotation transmits energy into the catalytic sites of the enzyme to produce the stepping action during rotation. One surprising and incompletely explained deduction based on the symmetries of c-rings in the rotor of the enzyme is that the amount of energy required by the ATP synthase to make an ATP molecule does not have a universal value. ATP synthases from multicellular organisms require the least energy, whereas the energy required to make an ATP molecule in unicellular organisms and chloroplasts is higher, and a range of values has been calculated. Finally, evidence is growing for other roles of ATP synthases in the inner membranes of mitochondria. Here the enzymes form supermolecular complexes, possibly with specific lipids, and these complexes probably contribute to, or even determine, the formation of the cristae.read more
Citations
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Journal ArticleDOI
Mitochondrial membrane potential.
Ljubava D. Zorova,Vasily A. Popkov,Egor Y. Plotnikov,Denis N. Silachev,Irina B. Pevzner,S. S. Jankauskas,V. A. Babenko,S. D. Zorov,Anastasia V. Balakireva,Magdalena Juhaszova,Steven J. Sollott,Dmitry B. Zorov,Dmitry B. Zorov +12 more
TL;DR: Additional potential mechanisms for which ΔΨm is essential for maintenance of cellular health and viability are proposed and recommendations how to accurately measure ΔΩm in a cell are provided and potential sources of artifacts are discussed.
Journal ArticleDOI
Sequence co-evolution gives 3D contacts and structures of protein complexes
Thomas A. Hopf,Charlotta P I Schärfe,Charlotta P I Schärfe,João P. G. L. M. Rodrigues,Anna G. Green,Oliver Kohlbacher,Chris Sander,Alexandre M. J. J. Bonvin,Debora S. Marks +8 more
TL;DR: Analysis of correlated evolutionary sequence changes across proteins identifies residues that are close in space with sufficient accuracy to determine the three-dimensional structure of the protein complexes, and predicts protein–protein contacts in 32 complexes of unknown structure.
Journal ArticleDOI
The Mitochondrial Permeability Transition Pore: Channel Formation by F-ATP Synthase, Integration in Signal Transduction, and Role in Pathophysiology
Paolo Bernardi,Andrea Rasola,Andrea Rasola,Andrea Rasola,Michael Forte,Giovanna Lippe,Giovanna Lippe,Giovanna Lippe +7 more
TL;DR: Structural and functional features of F-ATP synthases are discussed that may provide clues to its transition from an energy-conserving into anEnergy-dissipating device as well as recent advances on signal transduction to the PTP and on its role in cellular pathophysiology.
Journal ArticleDOI
Structure and conformational states of the bovine mitochondrial ATP synthase by cryo-EM
Anna Zhou,Alexis Rohou,Daniel G Schep,John V. Bason,Martin G. Montgomery,John E. Walker,Nikolaus Grigorieff,John L. Rubinstein +7 more
TL;DR: Cryo-EM analysis of the bovine mitochondrial ATP synthase revealed seven distinct states of the enzyme that show different modes of bending and twisting in the intact ATP synthases, suggesting a proton translocation path through the FO region that involves both the a and b subunits.
Journal ArticleDOI
Electron cryomicroscopy observation of rotational states in a eukaryotic V-ATPase
TL;DR: In this article, electron microscopy was used to obtain structures for three rotational states of the V-ATPase from the yeast Saccharomyces cerevisiae, showing that deformation during rotation enables the smooth transmission of power through rotary ATPases.
References
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Journal ArticleDOI
Structure at 2.8 A resolution of F1-ATPase from bovine heart mitochondria.
TL;DR: The crystal structure of bovine mitochondrial F1-ATPase determined at 2.8 Å resolution supports a catalytic mechanism in intact ATP synthase in which the three catalytic subunits are in different states of the catalytic cycle at any instant.
Journal ArticleDOI
Direct observation of the rotation of F1-ATPase
TL;DR: It is shown that a single molecule of F1-ATPase acts as a rotary motor, the smallest known, by direct observation of its motion by attaching a fluorescent actin filament to the γ-subunit as a marker, which enabled us to observe this motion directly.
Journal ArticleDOI
The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 A.
Tomitake Tsukihara,Hiroshi Aoyama,Eiki Yamashita,Takashi Tomizaki,Hiroshi Yamaguchi,Kyoko Shinzawa-Itoh,Ryosuke Nakashima,Rieko Yaono,Shinya Yoshikawa +8 more
TL;DR: Two possible proton pathways for pumping, each spanning from the matrix to the cytosolic surfaces, were identified, including hydrogen bonds, internal cavities likely to contain water molecules, and structures that could form hydrogen bonds with small possible conformational change of amino acid side chains.
Journal ArticleDOI
Structure at 2.8 A resolution of cytochrome c oxidase from Paracoccus denitrificans.
TL;DR: The crystal structure at 2.8 Å resolution of the four protein subunits containing cytochrome c oxidase from the soil bacterium Paracoccus denitrificans, complexed with an antibody Fv fragment, is described and mechanisms for proton pumping are discussed.