scholarly journals Mitochondrial F1FO ATP synthase determines the local proton motive force in cristae tips

2021 ◽  
Author(s):  
Bettina Rieger ◽  
Tasnim Arroum ◽  
Jimmy Villalta ◽  
Karin B. Busch
Keyword(s):  
Atp Synthase ◽  
Mammalian Cells ◽  
Atp Hydrolysis ◽  
Ph Sensor ◽  
Atp Synthesis ◽  
Proton Motive Force ◽  
Motive Force ◽  
List Type ◽  
Inner Mitochondrial Membrane ◽  
Respiratory Chain Complexes

ABSTRACTThe classical view of oxidative phosphorylation is that a proton motive force PMF generated by the respiratory chain complexes fuels ATP synthesis. Under glycolytic conditions, ATP synthase in its reverse mode also can contribute to the PMF. Here, we dissected the two functions of ATP synthase and the role of its inhibitory factor 1 (IF1) under different metabolic conditions in detail. pH profiles of mitochondrial sub-compartments were recorded with high spatial resolution in live mammalian cells by positioning a pH-sensor directly at F1 and FO of ATP synthase, complex IV and in the matrix. Our results clearly show that ATP synthase activity is substantially controlling the PMF and that IF1 is essential under OXPHOS conditions to prevent reverse ATP synthase activity due to an almost negligible ΔpH.GRAPHICAL ABSTRACTHIGHLIGHTSThe ΔpH along and across the inner mitochondrial membrane is not homogeneousThe proton motive force at cristae tips is controlled by F1 FO ATP synthaseUnder OXPHOS conditions, the pH difference between FO and F1 of active ATP synthase is almost negligible (1.2 proton vs. 1 proton equivalent)IF1 is required to prevent the onset of ATP hydrolysis under OXPHOS conditions

scholarly journals The Activity of the ATP Synthase fromEscherichia coliIs Regulated by the Transmembrane Proton Motive Force

2000 ◽  
Vol 275 (39) ◽  
pp. 30157-30162 ◽  
Author(s):  
Susanne Fischer ◽  
Peter Gräber ◽  
Paola Turina
Keyword(s):  
Atp Synthase ◽  
Proton Motive Force ◽  
Motive Force

scholarly journals Aerobic Growth of Escherichia coli Is Reduced, and ATP Synthesis Is Selectively Inhibited when Five C-terminal Residues Are Deleted from the ϵ Subunit of ATP Synthase

2015 ◽  
Vol 290 (34) ◽  
pp. 21032-21041 ◽  
Author(s):  
Naman B. Shah ◽  
Thomas M. Duncan
Keyword(s):  
Escherichia Coli ◽  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Intrinsic Rate ◽  
Synthesis Rate ◽  
Final Segment ◽  
Rotary Catalysis

F-type ATP synthases are rotary nanomotor enzymes involved in cellular energy metabolism in eukaryotes and eubacteria. The ATP synthase from Gram-positive and -negative model bacteria can be autoinhibited by the C-terminal domain of its ϵ subunit (ϵCTD), but the importance of ϵ inhibition in vivo is unclear. Functional rotation is thought to be blocked by insertion of the latter half of the ϵCTD into the central cavity of the catalytic complex (F1). In the inhibited state of the Escherichia coli enzyme, the final segment of ϵCTD is deeply buried but has few specific interactions with other subunits. This region of the ϵCTD is variable or absent in other bacteria that exhibit strong ϵ-inhibition in vitro. Here, genetically deleting the last five residues of the ϵCTD (ϵΔ5) caused a greater defect in respiratory growth than did the complete absence of the ϵCTD. Isolated membranes with ϵΔ5 generated proton-motive force by respiration as effectively as with wild-type ϵ but showed a nearly 3-fold decrease in ATP synthesis rate. In contrast, the ϵΔ5 truncation did not change the intrinsic rate of ATP hydrolysis with membranes. Further, the ϵΔ5 subunit retained high affinity for isolated F1 but reduced the maximal inhibition of F1-ATPase by ϵ from >90% to ∼20%. The results suggest that the ϵCTD has distinct regulatory interactions with F1 when rotary catalysis operates in opposite directions for the hydrolysis or synthesis of ATP.

scholarly journals Purification and Biochemical Characterization of the F1Fo-ATP Synthase from Thermoalkaliphilic Bacillus sp. Strain TA2.A1

2003 ◽  
Vol 185 (15) ◽  
pp. 4442-4449 ◽  
Author(s):  
Gregory M. Cook ◽  
Stefanie Keis ◽  
Hugh W. Morgan ◽  
Christoph von Ballmoos ◽  
Ulrich Matthey ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Biochemical Characterization ◽  
Atp Hydrolysis ◽  
Sodium Dodecyl ◽  
Electrical Potential ◽  
Atp Synthesis ◽  
Intrinsic Property ◽  
Protein Sequencing ◽  
Hydrolysis Activity

ABSTRACT We describe here purification and biochemical characterization of the F1Fo-ATP synthase from the thermoalkaliphilic organism Bacillus sp. strain TA2.A1. The purified enzyme produced the typical subunit pattern of an F1Fo-ATP synthase on a sodium dodecyl sulfate-polyacrylamide gel, with F1 subunits α, β, γ, δ, and ε and Fo subunits a, b, and c. The subunits were identified by N-terminal protein sequencing and mass spectroscopy. A notable feature of the ATP synthase from strain TA2.A1 was its specific blockage in ATP hydrolysis activity. ATPase activity was unmasked by using the detergent lauryldimethylamine oxide (LDAO), which activated ATP hydrolysis >15-fold. This activation was the same for either the F1Fo holoenzyme or the isolated F1 moiety, and therefore latent ATP hydrolysis activity is an intrinsic property of F1. After reconstitution into proteoliposomes, the enzyme catalyzed ATP synthesis driven by an artificially induced transmembrane electrical potential (Δψ). A transmembrane proton gradient or sodium ion gradient in the absence of Δψ was not sufficient to drive ATP synthesis. ATP synthesis was eliminated by the electrogenic protonophore carbonyl cyanide m-chlorophenylhydrazone, while the electroneutral Na+/H+ antiporter monensin had no effect. Neither ATP synthesis nor ATP hydrolysis was stimulated by Na+ ions, suggesting that protons are the coupling ions of the ATP synthase from strain TA2.A1, as documented previously for mesophilic alkaliphilic Bacillus species. The ATP synthase was specifically modified at its c subunits by N,N′-dicyclohexylcarbodiimide, and this modification inhibited ATP synthesis.

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.

scholarly journals Targeting Mycobacterial F-ATP Synthase C-Terminal α Subunit Interaction Motif on Rotary Subunit γ

Antibiotics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1456
Author(s):  
Amaravadhi Harikishore ◽  
Chui-Fann Wong ◽  
Priya Ragunathan ◽  
Dennis Litty ◽  
Volker Müller ◽  
...  
Keyword(s):  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Membrane Vesicles ◽  
Α Subunit ◽  
Rotational States ◽  
C Terminus ◽  
Inverted Membrane Vesicles ◽  
Hydrolysis Of ◽  
Micromolar Range

Mycobacteria regulate their energy (ATP) levels to sustain their survival even in stringent living conditions. Recent studies have shown that mycobacteria not only slow down their respiratory rate but also block ATP hydrolysis of the F-ATP synthase (α3:β3:γ:δ:ε:a:b:b’:c9) to maintain ATP homeostasis in situations not amenable for growth. The mycobacteria-specific α C-terminus (α533-545) has unraveled to be the major regulative of latent ATP hydrolysis. Its deletion stimulates ATPase activity while reducing ATP synthesis. In one of the six rotational states of F-ATP synthase, α533-545 has been visualized to dock deep into subunit γ, thereby blocking rotation of γ within the engine. The functional role(s) of this C-terminus in the other rotational states are not clarified yet and are being still pursued in structural studies. Based on the interaction pattern of the docked α533-545 region with subunit γ, we attempted to study the druggability of the α533-545 motif. In this direction, our computational work has led to the development of an eight-featured α533-545 peptide pharmacophore, followed by database screening, molecular docking, and pose selection, resulting in eleven hit molecules. ATP synthesis inhibition assays using recombinant ATP synthase as well as mycobacterial inverted membrane vesicles show that one of the hits, AlMF1, inhibited the mycobacterial F-ATP synthase in a micromolar range. The successful targeting of the α533-545-γ interaction motif demonstrates the potential to develop inhibitors targeting the α site to interrupt rotary coupling with ATP synthesis.

scholarly journals High-Resolution pH Imaging of Living Bacterial Cells To Detect Local pH Differences

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Yusuke V. Morimoto ◽  
Nobunori Kami-ike ◽  
Tomoko Miyata ◽  
Akihiro Kawamoto ◽  
Takayuki Kato ◽  
...  
Keyword(s):  
High Resolution ◽  
Atp Hydrolysis ◽  
Imaging System ◽  
Proton Motive Force ◽  
Energy Transduction ◽  
Protein Export ◽  
Motive Force ◽  
Bacterial Flagellum ◽  
Ph Imaging ◽  
Local Ph

ABSTRACTProtons are utilized for various biological activities such as energy transduction and cell signaling. For construction of the bacterial flagellum, a type III export apparatus utilizes ATP and proton motive force to drive flagellar protein export, but the energy transduction mechanism remains unclear. Here, we have developed a high-resolution pH imaging system to measure local pH differences within livingSalmonella entericacells, especially in close proximity to the cytoplasmic membrane and the export apparatus. The local pH near the membrane was ca. 0.2 pH unit higher than the bulk cytoplasmic pH. However, the local pH near the export apparatus was ca. 0.1 pH unit lower than that near the membrane. This drop of local pH depended on the activities of both transmembrane export components and FliI ATPase. We propose that the export apparatus acts as an H+/protein antiporter to couple ATP hydrolysis with H+flow to drive protein export.IMPORTANCEThe flagellar type III export apparatus is required for construction of the bacterial flagellum beyond the cellular membranes. The export apparatus consists of a transmembrane export gate and a cytoplasmic ATPase complex. The export apparatus utilizes ATP and proton motive force as the energy source for efficient and rapid protein export during flagellar assembly, but it remains unknown how. In this study, we have developed anin vivopH imaging system with high spatial and pH resolutions with a pH indicator probe to measure local pH near the export apparatus. We provide direct evidence suggesting that ATP hydrolysis by the ATPase complex and the following rapid protein translocation by the export gate are both linked to efficient proton translocation through the gate.

scholarly journals The structure of the catalytic domain of the ATP synthase fromMycobacterium smegmatisis a target for developing antitubercular drugs

2019 ◽  
Vol 116 (10) ◽  
pp. 4206-4211 ◽  
Author(s):  
Alice Tianbu Zhang ◽  
Martin G. Montgomery ◽  
Andrew G. W. Leslie ◽  
Gregory M. Cook ◽  
John E. Walker
Keyword(s):  
Atp Synthase ◽  
Mycobacterium Smegmatis ◽  
Catalytic Domain ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Geobacillus Stearothermophilus ◽  
Antitubercular Drugs ◽  
Atp Binding Site ◽  
E Coli ◽  
Catalytic Cycles

The crystal structure of the F1-catalytic domain of the adenosine triphosphate (ATP) synthase has been determined fromMycobacterium smegmatiswhich hydrolyzes ATP very poorly. The structure of the α3β3-component of the catalytic domain is similar to those in active F1-ATPases inEscherichia coliandGeobacillus stearothermophilus. However, its ε-subunit differs from those in these two active bacterial F1-ATPases as an ATP molecule is not bound to the two α-helices forming its C-terminal domain, probably because they are shorter than those in active enzymes and they lack an amino acid that contributes to the ATP binding site in active enzymes. InE. coliandG. stearothermophilus, the α-helices adopt an “up” state where the α-helices enter the α3β3-domain and prevent the rotor from turning. The mycobacterial F1-ATPase is most similar to the F1-ATPase fromCaldalkalibacillus thermarum, which also hydrolyzes ATP poorly. The βE-subunits in both enzymes are in the usual “open” conformation but appear to be occupied uniquely by the combination of an adenosine 5′-diphosphate molecule with no magnesium ion plus phosphate. This occupation is consistent with the finding that their rotors have been arrested at the same point in their rotary catalytic cycles. These bound hydrolytic products are probably the basis of the inhibition of ATP hydrolysis. It can be envisaged that specific as yet unidentified small molecules might bind to the F1domain inMycobacterium tuberculosis, prevent ATP synthesis, and inhibit the growth of the pathogen.

Photophosphorylation in Chloroplasts With Varied Proton Motive Force (PMF): II. Phosphorylation and the PMF

1982 ◽  
Vol 9 (4) ◽  
pp. 399 ◽  
Author(s):  
AB Hope ◽  
D Ranson ◽  
PG Dixon
Keyword(s):  
Time Lag ◽  
Atp Synthesis ◽  
Close Correlation ◽  
Proton Motive Force ◽  
Motive Force ◽  
Luciferase Assay ◽  
Time Lags ◽  
Constant Rate ◽  
Phosphorylation Reaction ◽  
The Mean

Measurements of ATP (luciferase assay) formed by class C pea chloroplasts in illumination times varying from 10 ms to 30 s are reported for control, + valinomycin and + nigericin conditions. ATP was made at a constant rate in controls following a time lag of a few milliseconds which varied with the illumination. Valinomycin increased the time lag to ~100 ms after which therate approached controls. Nigericin caused a gradual decrease in rate of ATP synthesis over a period of ~1s . In the steady state the rate was a different function of the transthylakoid pH difference (ΔpH) with nigericin and with valinomycin, with thresholds at ΔpH = 2.9 and 3.5 respectively. The time lags and thresholds are shown to be consistent with a threshold proton motive force (PMF) of 140-190 mV in various experiments. It is argued that this PMF corresponds to that required to poise the phosphorylation reaction to the point of ATP net synthesis at the prevailing dark phosphorylation potential. The experiments could not decide between a stoichiometry of 2 or 3 protons per ATP. Data suitable for use in constructing a kinetic model are briefly discussed. The findings generally are interpreted as showing a close correlation between phosphorylation and the PMF estimated as the mean potential energy of protons in the intrathylakoid spaces relative to the outside. It is concluded that Mitchellian coupling between bulk protons and the ATP synthetase is not yet to be discarded.

Sign in / Sign up

Export Citation Format

Share Document