ATP‐synthase of Rhodobacter capsulatus: coupling of proton flow through F0 to reactions in F1 under the ATP synthesis and slip conditions

Feniouk, Boris A.; Cherepanov, Dmitry A.; Junge, Wolfgang

doi:10.1016/s0014-5793(99)00160-x

Cited by 28 publications

(23 citation statements)

References 41 publications

(56 reference statements)

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“…An intrinsic partial uncoupling observed in the absence of ADP and P i has recently been reported for the ATP synthase from Rhodobacter capsulatus (36). Other forms of uncoupling caused by failure of linking rotation to proton movement through F 0 have also been reported (37)(38)(39)(40)(41)(42).…”

Section: Discussionmentioning

confidence: 70%

The Role of the ϵ Subunit in the Escherichia coli ATP Synthase

Cipriano

Dunn

2006

Journal of Biological Chemistry

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The role of the C-domain of the ⑀ subunit of ATP synthase was investigated by fusing either the 20-kDa flavodoxin (Fd) or the 5-kDa chitin binding domain (CBD) to the N termini of both fulllength ⑀ and a truncation mutant ⑀ 88-stop . All mutant ⑀ proteins were stable in cells and supported F 1 F 0 assembly. Cells expressing the Fd-⑀ or Fd-⑀ 88-stop mutants were unable to grow on acetate minimal medium, indicating their inability to carry out oxidative phosphorylation because of steric blockage of rotation. The other forms of ⑀ supported growth on acetate. Membrane vesicles containing Fd-⑀ showed 23% of the wild type ATPase activity but no proton pumping, suggesting that the ATP synthase is intrinsically partially uncoupled. Vesicles containing CBD-⑀ were indistinguishable from the wild type in ATPase activity and proton pumping, indicating that the N-terminal fusions alone do not promote uncoupling. Fd-⑀ 88-stop caused higher rates of uncoupled ATP hydrolysis than Fd-⑀, and ⑀ 88-stop showed an increased rate of membrane-bound ATP hydrolysis but decreased proton pumping relative to the wild type. Both results demonstrate the role of the C-domain in coupling. Analysis of the wild type and ⑀ 88-stop mutant membrane ATPase activities at concentrations of ATP from 50 M to 8 mM showed no significant dependence of the ratio of bound/released ATPase activity on ATP concentration. These results support the hypothesis that the main function of the C-domain in the Escherichia coli ⑀ subunit is to reduce uncoupled ATPase activity, rather than to regulate coupled activity.ATP synthase is the enzyme responsible for the formation of ATP during oxidative phosphorylation. This enzyme, found on the inner membranes of mitochondria and bacteria, and on the thylakoid membranes in chloroplasts, uses the energy stored in a transmembrane proton gradient to produce ATP from the precursors ADP and P i . The enzyme can be subdivided into two sectors. In Escherichia coli, the F 1 sector is composed of 5 different polypeptides with a stoichiometry of ␣ 3 ␤ 3 ␥␦⑀, and houses the three catalytic nucleotide binding sites. The F 0 sector forms a proton-specific pore and is comprised of three different integral membrane proteins, showing a stoichiometry of ab 2 c 10 . During ATP synthesis, protons move through the F 0 pore and drive the rotation of the c 10 ␥⑀ oligomer. Movement of this "rotor" drives the sequential conformational changes in ␣ 3 ␤ 3 that promote both the binding of substrates, ADP and P i , and the formation and release of ATP as predicted by the binding change mechanism of Paul Boyer (1). The two b subunits, combined with the ␦ subunit, form a peripheral stalk that connects the F 1 and F 0 sectors, preventing their rotation relative to each other. In E. coli, ATP synthase is reversible and under anaerobic conditions can act as an ATP-driven proton pump energizing the inner membrane to power membrane transporters and the flagellar motor. For recent reviews see Refs. 2-4.The ⑀ subunit, which lies at the interface of F 1 and F 0 ,...

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Section: Discussionmentioning

confidence: 70%

The Role of the ϵ Subunit in the Escherichia coli ATP Synthase

Cipriano

Dunn

2006

Journal of Biological Chemistry

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“…Neither bc 1 nor ATP synthase have been imaged by AFM of native photosynthetic membranes (27,70). Since as few as five bc 1 complexes and one ATP synthase are required per chromatophore, they may be clustered in a region not retained during fractionation before imaging (71,72). Suggestions put forth for their location include localization of both complexes to the pole of the vesicular chromatophore (30) or the neck of the chromatophore and the surrounding membrane (29).…”

Section: Discussionmentioning

confidence: 99%

Intrinsic Curvature Properties of Photosynthetic Proteins in Chromatophores

Chandler

Hsin

Harrison

et al. 2008

Biophysical Journal

135

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In purple bacteria, photosynthesis is carried out on large indentations of the bacterial plasma membrane termed chromatophores. Acting as primitive organelles, chromatophores are densely packed with the membrane proteins necessary for photosynthesis, including light harvesting complexes LH1 and LH2, reaction center (RC), and cytochrome bc(1). The shape of chromatophores is primarily dependent on species, and is typically spherical or flat. How these shapes arise from the protein-protein and protein-membrane interactions is still unknown. Now, using molecular dynamics simulations, we have observed the dynamic curvature of membranes caused by proteins in the chromatophore. A membrane-embedded array of LH2s was found to relax to a curved state, both for LH2 from Rps. acidophila and a homology-modeled LH2 from Rb. sphaeroides. A modeled LH1-RC-PufX dimer was found to develop a bend at the dimerizing interface resulting in a curved shape as well. In contrast, the bc(1) complex, which has not been imaged yet in native chromatophores, did not induce a preferred membrane curvature in simulation. Based on these results, a model for how the different photosynthetic proteins influence chromatophore shape is presented.

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“…oligomycins, venturicidins, ossamycins, apoptolidins) differ in the macrolide ring size and mainly in the sugar portion [34]. Interestingly, oligomycins, ossamycin and apoptolidin target specifically mitochondrial ATP synthases, while venturicidin also strongly inhibits bacterial ATP synthases [56]. The smaller macrolides bafilomycin and concanamycins are apparently less specific because they target V-type ATPases [57], but can also inhibit F-type ATPases [55].…”

Section: Macrolide Targets and Mutual Interactionsmentioning

confidence: 99%

Novel Drugs Targeting the c-Ring of the F1FO-ATP Synthase

Pagliarani

Nesci²,

Ventrella³

2016

MRMC

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Increasing evidence highlights the role of the ATP synthase/hydrolase, also known as F1FO-complex, as key molecular and enzymatic switch between cell life and death, thus increasing the enzyme attractiveness as drug target in pharmacology. Being inhibition of ATP production usually linked to antiproliferative properties, drugs targeting the enzyme complex have been mainly considered to fight pathogen parasites and cancer. In recent years, a number of natural macrolides, produced by bacterial fermentation and structurally related to the classical enzyme inhibitor oligomycin, have been shown to bind to the membrane-embedded FO sector and to inhibit the enzyme complex by an oligomycin-like mechanism, namely by interacting with the c-ring. Other than natural macrolide antibiotics, which display variegated inhibition power on different F1FO-complexes, synthetic compounds from the diarylquinoline and organotin families also target the c-ring and strongly inhibit the enzyme. Bioinformatic insights address drug design to target FO subunits. Additionally, the possible modulation of the drug inhibition power, by amino acid substitutions or post-translational modifications of c-subunits, adds further interest to the target. The present survey on compounds targeting the c-ring and bi-directionally blocking the transmembrane proton flux which drives ATP synthesis/hydrolysis, discloses new therapeutic options to fight cancer and infections sustained by therapeutically recalcitrant microorganisms. Additionally, c-ring targeting compounds may constitute new tools to eradicate undesired biofilms and to address at the molecular level the therapy of mammalian diseases linked to mitochondrial dysfunctions. In summary, studies on the only partially known molecular interactions within the c-ring of the F1FO-complex may renew hope to counteract mammalian diseases.

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ATP‐synthase of Rhodobacter capsulatus: coupling of proton flow through F₀ to reactions in F₁ under the ATP synthesis and slip conditions

Cited by 28 publications

References 41 publications

The Role of the ϵ Subunit in the Escherichia coli ATP Synthase

The Role of the ϵ Subunit in the Escherichia coli ATP Synthase

Intrinsic Curvature Properties of Photosynthetic Proteins in Chromatophores

Novel Drugs Targeting the c-Ring of the F<sub>1</sub>F<sub>O</sub>-ATP Synthase

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