Rotation of the γ-subunit in single membrane-bound H+-ATP synthases from chloroplasts during ATP synthesis

2020 ◽  
pp. 119-149
Author(s):  
Roland Bienert ◽  
Paola Turina ◽  
Michael Börsch ◽  
Peter Gräber
Keyword(s):  
Atp Synthesis ◽  
Γ Subunit ◽  
Single Membrane ◽  
Membrane Bound ◽  
Atp Synthases

scholarly journals Subunit Movements in Single Membrane-bound H+-ATP Synthases from Chloroplasts during ATP Synthesis

2009 ◽  
Vol 284 (52) ◽  
pp. 36240-36247 ◽  
Author(s):  
Roland Bienert ◽  
Verena Rombach-Riegraf ◽  
Manuel Diez ◽  
Peter Gräber
Keyword(s):  
Atp Synthesis ◽  
Single Membrane ◽  
Membrane Bound ◽  
Atp Synthases

scholarly journals An ATP synthase harboring an atypical γ-subunit is involved in ATP synthesis in tomato fruit chromoplasts

2013 ◽  
Vol 74 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Irini Pateraki ◽  
Marta Renato ◽  
Joaquín Azcón-Bieto ◽  
Albert Boronat
Keyword(s):  
Atp Synthase ◽  
Tomato Fruit ◽  
Atp Synthesis ◽  
Γ Subunit

scholarly journals Structure of a bacterial ATP synthase

2018 ◽  
Author(s):  
Hui Guo ◽  
Toshiharu Suzuki ◽  
John L. Rubinstein
Keyword(s):  
Atp Synthase ◽  
Biochemical Analysis ◽  
Atp Hydrolysis ◽  
Genetic Manipulation ◽  
Proton Translocation ◽  
Atp Synthesis ◽  
Mitochondrial Complex ◽  
Rotational States ◽  
Membrane Region ◽  
Atp Synthases

AbstractATP synthases produce ATP from ADP and inorganic phosphate with energy from a transmembrane proton motive force. Bacterial ATP synthases have been studied extensively because they are the simplest form of the enzyme and because of the relative ease of genetic manipulation of these complexes. We expressed theBacillusPS3 ATP synthase inEschericia coli, purified it, and imaged it by cryo-EM, allowing us to build atomic models of the complex in three rotational states. The position of subunitεshows how it is able to inhibit ATP hydrolysis while allowing ATP synthesis. The architecture of the membrane region shows how the simple bacterial ATP synthase is able to perform the same core functions as the equivalent, but more complicated, mitochondrial complex. The structures reveal the path of transmembrane proton translocation and provide a model for understanding decades of biochemical analysis interrogating the roles of specific residues in the enzyme.

Pyrophosphate as an alternative energy currency in plants

2021 ◽  
Vol 478 (8) ◽  
pp. 1515-1524
Author(s):  
Abir U. Igamberdiev ◽  
Leszek A. Kleczkowski
Keyword(s):  
Metabolic Pathways ◽  
Energy Efficient ◽  
Alternative Energy ◽  
Plant Cells ◽  
Atp Synthesis ◽  
Continuous Operation ◽  
Low Oxygen ◽  
Pyruvate Phosphate Dikinase ◽  
Oxygen Stress ◽  
Membrane Bound

In the conditions of [Mg2+] elevation that occur, in particular, under low oxygen stress and are the consequence of the decrease in [ATP] and increase in [ADP] and [AMP], pyrophosphate (PPi) can function as an alternative energy currency in plant cells. In addition to its production by various metabolic pathways, PPi can be synthesized in the combined reactions of pyruvate, phosphate dikinase (PPDK) and pyruvate kinase (PK) by so-called PK/PPDK substrate cycle, and in the reverse reaction of membrane-bound H+-pyrophosphatase, which uses the energy of electrochemical gradients generated on tonoplast and plasma membrane. The PPi can then be consumed in its active forms of MgPPi and Mg2PPi by PPi-utilizing enzymes, which require an elevated [Mg2+]. This ensures a continuous operation of glycolysis in the conditions of suppressed ATP synthesis, keeping metabolism energy efficient and less dependent on ATP.

A membrane-bound plastid inclusion in the epidermis of leaves of Taraxacum officinale

1977 ◽  
Vol 55 (2) ◽  
pp. 222-225 ◽  
Author(s):  
E. S. Martin ◽  
G. Larbalestier
Keyword(s):  
Inclusion Bodies ◽  
Functional Role ◽  
Taraxacum Officinale ◽  
Single Membrane ◽  
Membrane Bound ◽  
Dense Inclusion ◽  
Electron Dense Inclusion

Epidermal chloroplasts of Taraxacum officinale agg. contain large electron-dense inclusion bodies enclosed by a single membrane. These inclusion bodies were not observed in mesophyll chloroplasts. The origin and functional role of these structures is discussed.

scholarly journals Energy Conservation by the H2:Heterodisulfide Oxidoreductase from Methanosarcina mazei Gö1: Identification of Two Proton-Translocating Segments

1999 ◽  
Vol 181 (13) ◽  
pp. 4076-4080 ◽  
Author(s):  
Tina Ide ◽  
Sebastian Bäumer ◽  
Uwe Deppenmeier
Keyword(s):  
Electron Transport ◽  
Atp Synthase ◽  
Cytoplasmic Membrane ◽  
Respiratory Control ◽  
Atp Synthesis ◽  
Heterodisulfide Reductase ◽  
Methanosarcina Mazei ◽  
Energy Conserving ◽  
Membrane Bound ◽  
Synthase Inhibitor

ABSTRACT The membrane-bound H2:heterodisulfide oxidoreductase system of the methanogenic archaeon Methanosarcina mazeiGö1 catalyzed the H2-dependent reduction of 2-hydroxyphenazine and the dihydro-2-hydroxyphenazine-dependent reduction of the heterodisulfide of HS-CoM and HS-CoB (CoM-S-S-CoB). Washed inverted vesicles of this organism were found to couple both processes with the transfer of protons across the cytoplasmic membrane. The maximal H+/2e− ratio was 0.9 for each reaction. The electrochemical proton gradient (ΔμH+ ) thereby generated was shown to drive ATP synthesis from ADP plus Pi, exhibiting stoichiometries of 0.25 ATP synthesized per two electrons transported for both partial reactions. ATP synthesis and the generation of ΔμH+ were abolished by the uncoupler 3,5-di-tert-butyl-4-hydroxybenzylidenemalononitrile (SF 6847). The ATP synthase inhibitorN,N′-dicyclohexylcarbodiimide did not affect H+ translocation but led to an almost complete inhibition of ATP synthesis and decreased the electron transport rates. The latter effect was relieved by the addition of SF 6847. Thus, the energy-conserving systems showed a stringent coupling which resembles the phenomenon of respiratory control. The results indicate that two different proton-translocating segments are present in the H2:heterodisulfide oxidoreductase system; the first involves the 2-hydroxyphenazine-dependent hydrogenase, and the second involves the heterodisulfide reductase.

Ultrastructural Cytochemistry of Some Oxidative Enzymes

1974 ◽  
Vol 32 ◽  
pp. 322-323
Author(s):  
Arnold M. Seligman
Keyword(s):  
Electron Transport ◽  
Cytochrome C ◽  
Succinic Dehydrogenase ◽  
Atp Synthesis ◽  
Oxidative Enzymes ◽  
Reaction Products ◽  
Inner Mitochondrial Membrane ◽  
Design And Synthesis ◽  
Membrane Bound ◽  
Membrane Bound Enzymes

The membrane-bound enzymes of the succinic oxidase chain of electron transport on the cristae of mitochondria have been the target of ultrastructural cytochemical research for a number of years. Methods for succinic dehydrogenase have been improved by the continuous design and synthesis of better tetrazolium salts. The most recent is BSPT, which is not osmiophilic, but yields an osmiophilic, lipophobic, insoluble formazan. The terminal triplet of the chain of electron transport or cytochrome oxidase, consisting of cytochrome c, a and a3 has been demonstrated very well via cytochrome c with diaminobenzidine (DAB). The localization of these two reaction products specifically on the outer surface of the inner mitochondrial membrane, lends some support to speculation concerning the mechanism of transfer of oxidative energy for ATP synthesis.

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