scholarly journals Helical arrays of U-shaped ATP synthase dimers form tubular cristae in ciliate mitochondria

2016 ◽  
Vol 113 (30) ◽  
pp. 8442-8447 ◽  
Author(s):  
Alexander W. Mühleip ◽  
Friederike Joos ◽  
Christoph Wigge ◽  
Achilleas S. Frangakis ◽  
Werner Kühlbrandt ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Protein Complexes ◽  
Paramecium Tetraurelia ◽  
Mitochondrial Atp Synthase ◽  
Structural Differences ◽  
Membrane Protein Complexes ◽  
Subtomogram Averaging ◽  
Electron Cryotomography ◽  
Energy Converting

F1Fo-ATP synthases are universal energy-converting membrane protein complexes that synthesize ATP from ADP and inorganic phosphate. In mitochondria of yeast and mammals, the ATP synthase forms V-shaped dimers, which assemble into rows along the highly curved ridges of lamellar cristae. Using electron cryotomography and subtomogram averaging, we have determined the in situ structure and organization of the mitochondrial ATP synthase dimer of the ciliate Paramecium tetraurelia. The ATP synthase forms U-shaped dimers with parallel monomers. Each complex has a prominent intracrista domain, which links the c-ring of one monomer to the peripheral stalk of the other. Close interaction of intracrista domains in adjacent dimers results in the formation of helical ATP synthase dimer arrays, which differ from the loose dimer rows in all other organisms observed so far. The parameters of the helical arrays match those of the cristae tubes, suggesting the unique features of the P. tetraurelia ATP synthase are directly responsible for generating the helical tubular cristae. We conclude that despite major structural differences between ATP synthase dimers of ciliates and other eukaryotes, the formation of ATP synthase dimer rows is a universal feature of mitochondria and a fundamental determinant of cristae morphology.

scholarly journals Mitochondrial ATP synthase dimers spontaneously self-associate driven by a long-ranged membrane-induced force

2018 ◽  
Author(s):  
Claudio Anselmi ◽  
Karen M. Davies ◽  
José D. Faraldo-Gómez
Keyword(s):  
Atp Synthase ◽  
Protein Interactions ◽  
Simulation Analysis ◽  
Protein Complexes ◽  
Protein Protein Interactions ◽  
Inner Mitochondrial Membrane ◽  
Atp Production ◽  
Mitochondrial Atp Synthase ◽  
Membrane Protein Complexes ◽  
Atp Synthases

AbstractATP synthases populate the inner membranes of mitochondria, where they produce the majority of the ATP required by the cell. Cryo-electron tomograms of these membranes from yeast to vertebrates have consistently revealed a very precise organization of these enzymes. Rather than being scattered throughout the membrane, the ATP synthases form dimers, and these dimers are organized into rows that extend for hundreds of nanometers. These rows are only observed in the membrane invaginations known as cristae, specifically along their sharply curved edges. Although the presence of these macromolecular structures has been irrefutably linked to the proper development of cristae morphology, it has been unclear what drives the formation of the rows and why they are specifically localized in the cristae. We present the result of a quantitative molecular-simulation analysis that strongly suggests that the ATP synthase dimers organize into rows spontaneously, driven by a long-ranged attractive force that results from relief in the overall elastic strain of the membrane. This strain is caused by the V-like shape of the dimers, unique among membrane-protein complexes, which induces a strong deformation in the surrounding membrane. The process of row formation is therefore not a result of protein-protein interactions, or of a specific lipid composition of the membrane. We further hypothesize that once assembled, the ATP synthase dimer rows prime the inner mitochondrial membrane to develop folds and invaginations, by causing macroscopic membrane ridges that ultimately become the cristae edges. In this view, mitochondrial ATP synthases would contribute to the generation of a morphology that maximizes the surface area of the inner membrane, and thus ATP production. Finally, we outline the key experiments that would be required to verify or refute this hypothesis.

scholarly journals In situ structure of trypanosomal ATP synthase dimer reveals a unique arrangement of catalytic subunits

2017 ◽  
Vol 114 (5) ◽  
pp. 992-997 ◽  
Author(s):  
Alexander W. Mühleip ◽  
Caroline E. Dewar ◽  
Achim Schnaufer ◽  
Werner Kühlbrandt ◽  
Karen M. Davies
Keyword(s):  
Atp Synthase ◽  
Conformational Changes ◽  
Atp Synthesis ◽  
Α Subunit ◽  
Catalytic Subunits ◽  
Mitochondrial Atp Synthase ◽  
The Individual ◽  
Electron Cryotomography ◽  
Atp Synthases

We used electron cryotomography and subtomogram averaging to determine the in situ structures of mitochondrial ATP synthase dimers from two organisms belonging to the phylum euglenozoa:Trypanosoma brucei, a lethal human parasite, andEuglena gracilis,a photosynthetic protist. At a resolution of 32.5 Å and 27.5 Å, respectively, the two structures clearly exhibit a noncanonical F1head, in which the catalytic (αβ)3assembly forms a triangular pyramid rather than the pseudo-sixfold ring arrangement typical of all other ATP synthases investigated so far. Fitting of known X-ray structures reveals that this unusual geometry results from a phylum-specific cleavage of the α subunit, in which the C-terminal αCfragments are displaced by ∼20 Å and rotated by ∼30° from their expected positions. In this location, the αCfragment is unable to form the conserved catalytic interface that was thought to be essential for ATP synthesis, and cannot convert γ-subunit rotation into the conformational changes implicit in rotary catalysis. The new arrangement of catalytic subunits suggests that the mechanism of ATP generation by rotary ATPases is less strictly conserved than has been generally assumed. The ATP synthases of these organisms present a unique model system for discerning the individual contributions of the α and β subunits to the fundamental process of ATP synthesis.

scholarly journals In situ structure and organization of the influenza C virus surface glycoprotein

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Steinar Halldorsson ◽  
Kasim Sader ◽  
Jack Turner ◽  
Lesley J. Calder ◽  
Peter B. Rosenthal
Keyword(s):  
Membrane Fusion ◽  
Hexagonal Lattice ◽  
Surface Glycoprotein ◽  
Structural Basis ◽  
Virus Surface ◽  
The Matrix ◽  
Influenza C Virus ◽  
Subtomogram Averaging ◽  
Electron Cryotomography

AbstractThe lipid-enveloped influenza C virus contains a single surface glycoprotein, the haemagglutinin-esterase-fusion (HEF) protein, that mediates receptor binding, receptor destruction, and membrane fusion at the low pH of the endosome. Here we apply electron cryotomography and subtomogram averaging to describe the structural basis for hexagonal lattice formation by HEF on the viral surface. The conformation of the glycoprotein in situ is distinct from the structure of the isolated trimeric ectodomain, showing that a splaying of the membrane distal domains is required to mediate contacts that form the lattice. The splaying of these domains is also coupled to changes in the structure of the stem region which is involved in membrane fusion, thereby linking HEF’s membrane fusion conformation with its assembly on the virus surface. The glycoprotein lattice can form independent of other virion components but we show a major role for the matrix layer in particle formation.

scholarly journals A Novel Chloroplast Super-Complex Consisting of the ATP Synthase and Photosystem I Reaction Center

2019 ◽  
Author(s):  
Satarupa Bhaduri ◽  
Sandeep K Singh ◽  
Whitaker Cohn ◽  
S. Saif Hasan ◽  
Julian P. Whitelegge ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Membrane Protein ◽  
Reaction Center ◽  
Atp Synthase ◽  
Photosystem I ◽  
Protein Complexes ◽  
Thylakoid Membranes ◽  
Native Page ◽  
Membrane Protein Complexes ◽  
Reaction Center Complexes

AbstractSeveral ‘super-complexes’ of individual hetero-oligomeric membrane protein complexes, whose function is to facilitate intra-membrane electron and proton transfer and harvesting of light energy, have been previously characterized in the mitochondrial cristae and chloroplast thylakoid membranes. The latter membrane is reported here to also be the location of an intra-membrane super-complex which is dominated by the ATP-synthase and photosystem I (PSI) reaction-center complexes, defined by mass spectrometry, clear-native PAGE and Western Blot analyses. This is the first documented presence of ATP synthase in a super-complex with the PSI reaction-center located in the non-appressed stromal domain of the thylakoid membrane.

scholarly journals Dye-ligand chromatographic purification of intact multisubunit membrane protein complexes: application to the chloroplast H+-F0F1-ATP synthase

2000 ◽  
Vol 346 (1) ◽  
pp. 41-44
Author(s):  
Holger SEELERT ◽  
Ansgar POETSCH ◽  
Meino ROHLFS ◽  
Norbert A. DENCHER
Keyword(s):  
Membrane Protein ◽  
Phosphatidic Acid ◽  
Ammonium Sulphate ◽  
Atp Synthase ◽  
Protein Complex ◽  
Protein Complexes ◽  
Atp Synthesis ◽  
Chromatographic Purification ◽  
Membrane Protein Complexes ◽  
Fof1 Atp Synthase

n-Dodecyl-β-D-maltoside was used as a detergent to solubilize the ammonium sulphate precipitate of chloroplast FOF1-ATP synthase, which was purified further by dye-ligand chromatography. Upon reconstitution of the purified protein complex into phosphatidylcholine/phosphatidic acid liposomes, ATP synthesis, driven by an artificial ∆pH/∆ψ, was observed. The highest activity was achieved with ATP synthase solubilized in n-dodecyl-β-D-maltoside followed by chromatography with Red 120 dye. The optimal dye for purification with CHAPS was Green 5. All known subunits were present in the monodisperse proton-translocating ATP synthase preparation obtained from chloroplasts.

scholarly journals ­­Mitochondrial ATP synthase dimers spontaneously associate due to a long-range membrane-induced force­

2018 ◽  
Vol 150 (5) ◽  
pp. 763-770 ◽  
Author(s):  
Claudio Anselmi ◽  
Karen M. Davies ◽  
José D. Faraldo-Gómez
Keyword(s):  
Long Range ◽  
Atp Synthase ◽  
Protein Interactions ◽  
Simulation Analysis ◽  
Protein Complexes ◽  
Protein Protein Interactions ◽  
Inner Mitochondrial Membrane ◽  
Atp Production ◽  
Mitochondrial Atp Synthase ◽  
Atp Synthases

Adenosine triphosphate (ATP) synthases populate the inner membranes of mitochondria, where they produce the majority of the ATP required by the cell. From yeast to vertebrates, cryoelectron tomograms of these membranes have consistently revealed a very precise organization of these enzymes. Rather than being scattered throughout the membrane, the ATP synthases form dimers, and these dimers are organized into rows that extend for hundreds of nanometers. The rows are only observed in the membrane invaginations known as cristae, specifically along their sharply curved edges. Although the presence of these macromolecular structures has been irrefutably linked to the proper development of cristae morphology, it has been unclear what drives the formation of the rows and why they are specifically localized in the cristae. In this study, we present a quantitative molecular-simulation analysis that strongly suggests that the dimers of ATP synthases organize into rows spontaneously, driven by a long-range attractive force that arises from the relief of the overall elastic strain of the membrane. The strain is caused by the V-like shape of the dimers, unique among membrane protein complexes, which induces a strong deformation in the surrounding membrane. The process of row formation is therefore not a result of direct protein–protein interactions or a specific lipid composition of the membrane. We further hypothesize that, once assembled, the ATP synthase dimer rows prime the inner mitochondrial membrane to develop folds and invaginations by causing macroscopic membrane ridges that ultimately become the edges of cristae. In this way, mitochondrial ATP synthases would contribute to the generation of a morphology that maximizes the surface area of the inner membrane, and thus ATP production. Finally, we outline key experiments that would be required to verify or refute this hypothesis.

scholarly journals Visualizing active membrane protein complexes by electron cryotomography

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Vicki A.M. Gold ◽  
Raffaele Ieva ◽  
Andreas Walter ◽  
Nikolaus Pfanner ◽  
Martin van der Laan ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Protein Complexes ◽  
Active Membrane ◽  
Membrane Protein Complexes ◽  
Electron Cryotomography

scholarly journals Dimers of mitochondrial ATP synthase induce membrane curvature and self-assemble into rows

2019 ◽  
Vol 116 (10) ◽  
pp. 4250-4255 ◽  
Author(s):  
Thorsten B. Blum ◽  
Alexander Hahn ◽  
Thomas Meier ◽  
Karen M. Davies ◽  
Werner Kühlbrandt
Keyword(s):  
Lipid Bilayer ◽  
Yarrowia Lipolytica ◽  
Atp Synthase ◽  
Membrane Curvature ◽  
Specific Lipids ◽  
Inner Membrane ◽  
Mitochondrial Atp Synthase ◽  
Mitochondrial Morphogenesis ◽  
Electron Cryotomography ◽  
Main Factor

Mitochondrial ATP synthases form dimers, which assemble into long ribbons at the rims of the inner membrane cristae. We reconstituted detergent-purified mitochondrial ATP synthase dimers from the green algaePolytomellasp. and the yeastYarrowia lipolyticainto liposomes and examined them by electron cryotomography. Tomographic volumes revealed that ATP synthase dimers from both species self-assemble into rows and bend the lipid bilayer locally. The dimer rows and the induced degree of membrane curvature closely resemble those in the inner membrane cristae. Monomers of mitochondrial ATP synthase reconstituted into liposomes do not bend membrane visibly and do not form rows. No specific lipids or proteins other than ATP synthase dimers are required for row formation and membrane remodelling. Long rows of ATP synthase dimers are a conserved feature of mitochondrial inner membranes. They are required for cristae formation and a main factor in mitochondrial morphogenesis.

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