scholarly journals Structure of the mitochondrial ATP synthase from Pichia angusta determined by electron cryo-microscopy

2016 ◽  
Vol 113 (45) ◽  
pp. 12709-12714 ◽  
Author(s):  
Kutti R. Vinothkumar ◽  
Martin G. Montgomery ◽  
Sidong Liu ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Catalytic Domain ◽  
Lateral Force ◽  
Membrane Domain ◽  
Subunit A ◽  
Mechanical Coupling ◽  
Peripheral Stalk ◽  
Mitochondrial Atp Synthase ◽  
A Subunit ◽  
Pichia Angusta

The structure of the intact monomeric ATP synthase from the fungus, Pichia angusta, has been solved by electron cryo-microscopy. The structure provides insights into the mechanical coupling of the transmembrane proton motive force across mitochondrial membranes in the synthesis of ATP. This mechanism requires a strong and integral stator, consisting of the catalytic α3β3-domain, peripheral stalk, and, in the membrane domain, subunit a and associated supernumerary subunits, kept in contact with the rotor turning at speeds up to 350 Hz. The stator’s integrity is ensured by robust attachment of both the oligomycin sensitivity conferral protein (OSCP) to the catalytic domain and the membrane domain of subunit b to subunit a. The ATP8 subunit provides an additional brace between the peripheral stalk and subunit a. At the junction between the OSCP and the apparently stiff, elongated α-helical b-subunit and associated d- and h-subunits, an elbow or joint allows the stator to bend to accommodate lateral movements during the activity of the catalytic domain. The stator may also apply lateral force to help keep the static a-subunit and rotating c10-ring together. The interface between the c10-ring and the a-subunit contains the transmembrane pathway for protons, and their passage across the membrane generates the turning of the rotor. The pathway has two half-channels containing conserved polar residues provided by a bundle of four α-helices inclined at ∼30° to the plane of the membrane, similar to those described in other species. The structure provides more insights into the workings of this amazing machine.

scholarly journals Permeability transition in human mitochondria persists in the absence of peripheral stalk subunits of ATP synthase

2017 ◽  
Vol 114 (34) ◽  
pp. 9086-9091 ◽  
Author(s):  
Jiuya He ◽  
Joe Carroll ◽  
Shujing Ding ◽  
Ian M. Fearnley ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Catalytic Domain ◽  
Atp Synthesis ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Helical Structure ◽  
Cyclophilin D ◽  
Membrane Domain ◽  
Peripheral Stalk ◽  
Subunit B

The opening of a nonspecific channel, known as the permeability transition pore (PTP), in the inner membranes of mitochondria can be triggered by calcium ions, leading to swelling of the organelle, disruption of the inner membrane and ATP synthesis, and cell death. Pore opening can be inhibited by cyclosporin A mediated via cyclophilin D. It has been proposed that the pore is associated with the dimeric ATP synthase and the oligomycin sensitivity conferral protein (OSCP), a component of the enzyme’s peripheral stalk, provides the site at which cyclophilin D interacts. Subunit b contributes a central α-helical structure to the peripheral stalk, extending from near the top of the enzyme’s catalytic domain and crossing the membrane domain of the enzyme via two α-helices. We investigated the possible involvement of the subunit b and the OSCP in the PTP by generating clonal cells, HAP1-Δb and HAP1-ΔOSCP, lacking the membrane domain of subunit b or the OSCP, respectively, in which the corresponding genes, ATP5F1 and ATP5O, had been disrupted. Both cell lines preserve the characteristic properties of the PTP; therefore, the membrane domain of subunit b does not contribute to the PTP, and the OSCP does not provide the site of interaction with cyclophilin D. The membrane subunits ATP6, ATP8, and subunit c have been eliminated previously from possible participation in the PTP; thus, the only subunits of ATP synthase that could participate in pore formation are e, f, g, diabetes-associated protein in insulin-sensitive tissues (DAPIT), and the 6.8-kDa proteolipid.

scholarly journals Altered properties of mitochondrial ATP-synthase in patients with a T → G mutation in the ATPase 6 (subunit a) gene at position 8993 of mtDNA

1995 ◽  
Vol 1271 (2-3) ◽  
pp. 349-357 ◽  
Author(s):  
Josef Houštek ◽  
Petr Klement ◽  
Jana Hermanska ◽  
Hana Houšťková ◽  
Hana Hansíková ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Subunit A ◽  
Mitochondrial Atp Synthase ◽  
Atpase 6

The a subunit asymmetry dictates the two opposite rotation directions in the synthesis and hydrolysis of ATP by the mitochondrial ATP synthase

2015 ◽  
Vol 84 (1) ◽  
pp. 53-57 ◽  
Author(s):  
Salvatore Nesci ◽  
Fabiana Trombetti ◽  
Vittoria Ventrella ◽  
Alessandra Pagliarani
Keyword(s):  
Atp Synthase ◽  
Mitochondrial Atp Synthase ◽  
A Subunit ◽  
Hydrolysis Of

scholarly journals Structure and conformational states of the bovine mitochondrial ATP synthase by cryo-EM

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Anna Zhou ◽  
Alexis Rohou ◽  
Daniel G Schep ◽  
John V Bason ◽  
Martin G Montgomery ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Catalytic Mechanism ◽  
Proton Translocation ◽  
Atp Synthesis ◽  
Bioinformatic Analysis ◽  
Mitochondrial Atp Synthase ◽  
A Subunit ◽  
Classification Of Images ◽  
Atp Synthases

Adenosine triphosphate (ATP), the chemical energy currency of biology, is synthesized in eukaryotic cells primarily by the mitochondrial ATP synthase. ATP synthases operate by a rotary catalytic mechanism where proton translocation through the membrane-inserted FO region is coupled to ATP synthesis in the catalytic F1 region via rotation of a central rotor subcomplex. We report here single particle electron cryomicroscopy (cryo-EM) analysis of the bovine mitochondrial ATP synthase. Combining cryo-EM data with bioinformatic analysis allowed us to determine the fold of the a subunit, suggesting a proton translocation path through the FO region that involves both the a and b subunits. 3D classification of images revealed seven distinct states of the enzyme that show different modes of bending and twisting in the intact ATP synthase. Rotational fluctuations of the c8-ring within the FO region support a Brownian ratchet mechanism for proton-translocation-driven rotation in ATP synthases.

scholarly journals Near-Neighbor Relationships of the Atypical Subunits that Form the Peripheral Stalk of the Mitochondrial ATP Synthase in Chlorophycean Algae

2017 ◽  
Vol 112 (3) ◽  
pp. 2a-3a
Author(s):  
Miriam Vázquez-Acevedo ◽  
Félix Vega-DeLuna ◽  
Lorenzo Sánchez-Vásquez ◽  
Lilia Colina-Tenorio ◽  
Claire Remacle ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Near Neighbor ◽  
Peripheral Stalk ◽  
Mitochondrial Atp Synthase ◽  
Neighbor Relationships

Inhibitors of the catalytic domain of mitochondrial ATP synthase

2006 ◽  
Vol 34 (5) ◽  
pp. 989-992 ◽  
Author(s):  
J.R. Gledhill ◽  
J.E. Walker
Keyword(s):  
Atp Synthase ◽  
Binding Sites ◽  
Catalytic Domain ◽  
Structural Studies ◽  
Inhibitor Protein ◽  
X Ray ◽  
F1 Atpase ◽  
X Ray Crystallography ◽  
Mitochondrial Atp Synthase ◽  
Natural Inhibitor

An understanding of the mechanism of ATP synthase requires an explanation of how inhibitors act. The catalytic F1-ATPase domain of the enzyme has been studied extensively by X-ray crystallography in a variety of inhibited states. Four independent inhibitory sites have been identified by high-resolution structural studies. They are the catalytic site, and the binding sites for the antibiotics aurovertin and efrapeptin and for the natural inhibitor protein, IF1.

scholarly journals Mitochondrial ATP Synthase Subunit d, a Component of the Peripheral Stalk, is Essential for Growth and Heat Stress Tolerance in Arabidopsis thaliana

2021 ◽  
Author(s):  
Tianxiang Liu ◽  
Jesse Arsenault ◽  
Elizabeth Vierling ◽  
Minsoo Kim
Keyword(s):  
Arabidopsis Thaliana ◽  
Heat Stress ◽  
Plant Growth ◽  
Mitochondrial Dysfunction ◽  
Stress Tolerance ◽  
Atp Synthase ◽  
Peripheral Stalk ◽  
Cellular Processes ◽  
Mitochondrial Atp Synthase ◽  
Heat Stress Tolerance

SUMMARYAs rapid changes in climate threaten global crop yields, an understanding of plant heat stress tolerance is increasingly relevant. Heat stress tolerance involves the coordinated action of many cellular processes and is particularly energy demanding. We acquired a knockout mutant and generated knockdown lines in Arabidopsis thaliana of the d subunit of mitochondrial ATP synthase (gene name: ATPQ, AT3G52300, referred to hereafter as ATPd), a subunit of the peripheral stalk, and used these to investigate the phenotypic significance of this subunit in normal growth and heat stress tolerance. Homozygous knockout mutants for ATPd could not be obtained due to gametophytic defects, while heterozygotes possess no visible phenotype. Therefore, we used RNAi to create knockdown plant lines for further studies. Proteomic analysis and blue native gels revealed that ATPd downregulation impairs only subunits of the mitochondrial ATP synthase (complex V of the electron transport chain). Knockdown plants were more sensitive to heat stress, had abnormal leaf morphology, and were severely slow growing compared to wild type. These results indicate that ATPd plays a crucial role in proper function of the mitochondrial ATP synthase holoenzyme, which, when reduced, leads to wide-ranging defects in energy-demanding cellular processes. In knockdown plants, more hydrogen peroxide accumulated and mitochondrial dysfunction stimulon (MDS) genes were activated. These data establish the essential structural role of ATPd and provide new information about complex V assembly and quality control, as well as support the importance of mitochondrial respiration in normal plant growth and heat stress tolerance.SIGNIFICANCE STATEMENTThe energy converter, mitochondrial ATP synthase, is critical for all organisms, but the functional importance of ATP synthase subunit d remains largely unknown in plants. We demonstrate the contributions of subunit d to plant growth, development, and heat stress tolerance, as well as to ATP synthase stability, ROS signaling and mitochondrial dysfunction regulation.

scholarly journals Structure of the dimeric ATP synthase from bovine mitochondria

2020 ◽  
Vol 117 (38) ◽  
pp. 23519-23526 ◽  
Author(s):  
Tobias E. Spikes ◽  
Martin G. Montgomery ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Enzyme Complex ◽  
Membrane Domains ◽  
Mitochondrial Matrix ◽  
Membrane Domain ◽  
Rotational States ◽  
Peripheral Stalk ◽  
B Subunit ◽  
Proton Uptake ◽  
Grotthus Mechanism

The structure of the dimeric ATP synthase from bovine mitochondria determined in three rotational states by electron cryo-microscopy provides evidence that the proton uptake from the mitochondrial matrix via the proton inlet half channel proceeds via a Grotthus mechanism, and a similar mechanism may operate in the exit half channel. The structure has given information about the architecture and mechanical constitution and properties of the peripheral stalk, part of the membrane extrinsic region of the stator, and how the action of the peripheral stalk damps the side-to-side rocking motions that occur in the enzyme complex during the catalytic cycle. It also describes wedge structures in the membrane domains of each monomer, where the skeleton of each wedge is provided by three α-helices in the membrane domains of the b-subunit to which the supernumerary subunits e, f, and g and the membrane domain of subunit A6L are bound. Protein voids in the wedge are filled by three specifically bound cardiolipin molecules and two other phospholipids. The external surfaces of the wedges link the monomeric complexes together into the dimeric structures and provide a pivot to allow the monomer–monomer interfaces to change during catalysis and to accommodate other changes not related directly to catalysis in the monomer–monomer interface that occur in mitochondrial cristae. The structure of the bovine dimer also demonstrates that the structures of dimeric ATP synthases in a tetrameric porcine enzyme have been seriously misinterpreted in the membrane domains.

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