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Sekiya M. Proton Pumping ATPases: Rotational Catalysis, Physiological Roles in Oral Pathogenic Bacteria, and Inhibitors. Biol Pharm Bull 2022; 45:1404-1411. [PMID: 36184496 DOI: 10.1248/bpb.b22-00396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proton pumping ATPases, both F-type and V/A-type ATPases, generate ATP using electrochemical energy or pump protons/sodium ions by hydrolyzing ATP. The enzymatic reaction and proton transport are coupled through subunit rotation, and this unique rotational mechanism (rotational catalysis) has been intensively studied. Single-molecule and thermodynamic analyses have revealed the detailed rotational mechanism, including the catalytically inhibited state and the roles of subunit interactions. In mammals, F- and V-ATPases are involved in ATP synthesis and organelle acidification, respectively. Most bacteria, including anaerobes, have F- and/or A-ATPases in the inner membrane. However, these ATPases are not believed to be essential in anaerobic bacteria since anaerobes generate sufficient ATP without oxidative phosphorylation. Recent studies suggest that F- and A-ATPases perform indispensable functions beyond ATP synthesis in oral pathogenic anaerobes; F-ATPase is involved in acid tolerance in Streptococcus mutans, and A-ATPase mediates nutrient import in Porphyromonas gingivalis. Consistently, inhibitors of oral bacterial F- and A-ATPases, such as phytopolyphenols and bedaquiline, strongly diminish growth and survival. Herein, we discuss rotational catalysis of bacterial F- and A-ATPases, and discuss their physiological roles, focusing on oral bacteria. We also review the effects of ATPase inhibitors on the growth and survival of oral pathogenic bacteria. The features of the catalytic mechanism and unique physiological roles in oral bacteria highlight the potential for proton pumping ATPases to serve as targets for oral antimicrobial agents.
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Affiliation(s)
- Mizuki Sekiya
- Division of Biochemistry, School of Pharmacy, Iwate Medical University
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2
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Iwamoto-Kihara A. Regulatory Mechanisms and Environmental Adaptation of the F-ATPase Family. Biol Pharm Bull 2022; 45:1412-1418. [PMID: 36184497 DOI: 10.1248/bpb.b22-00419] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The F-type ATPase family of enzymes, including ATP synthases, are found ubiquitously in biological membranes. ATP synthesis from ADP and inorganic phosphate is driven by an electrochemical H+ gradient or H+ motive force, in which intramolecular rotation of F-type ATPase is generated with H+ transport across the membranes. Because this rotation is essential for energy coupling between catalysis and H+-transport, regulation of the rotation is important to adapt to environmental changes and maintain ATP concentration. Recently, a series of cryo-electron microscopy images provided detailed insights into the structure of the H+ pathway and the multiple subunit arrangement. However, the regulatory mechanism of the rotation has not been clarified. This review describes the inhibition mechanism of ATP hydrolysis in bacterial enzymes. In addition, properties of the F-type ATPase of Streptococcus mutans, which acts as a H+-pump in an acidic environment, are described. These findings may help in the development of novel antimicrobial agents.
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3
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Rotor subunits adaptations in ATP synthases from photosynthetic organisms. Biochem Soc Trans 2021; 49:541-550. [PMID: 33890627 PMCID: PMC8106487 DOI: 10.1042/bst20190936] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/17/2021] [Accepted: 03/22/2021] [Indexed: 11/17/2022]
Abstract
Driven by transmembrane electrochemical ion gradients, F-type ATP synthases are the primary source of the universal energy currency, adenosine triphosphate (ATP), throughout all domains of life. The ATP synthase found in the thylakoid membranes of photosynthetic organisms has some unique features not present in other bacterial or mitochondrial systems. Among these is a larger-than-average transmembrane rotor ring and a redox-regulated switch capable of inhibiting ATP hydrolysis activity in the dark by uniquely adapted rotor subunit modifications. Here, we review recent insights into the structure and mechanism of ATP synthases specifically involved in photosynthesis and explore the cellular physiological consequences of these adaptations at short and long time scales.
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4
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Krah A, Huber RG, McMillan DGG, Bond PJ. The Molecular Basis for Purine Binding Selectivity in the Bacterial ATP Synthase ϵ Subunit. Chembiochem 2020; 21:3249-3254. [PMID: 32608105 DOI: 10.1002/cbic.202000291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/30/2020] [Indexed: 12/21/2022]
Abstract
The ϵ subunit of ATP synthases has been proposed to regulate ATP hydrolysis in bacteria. Prevailing evidence supports the notion that when the ATP concentration falls below a certain threshold, the ϵ subunit changes its conformation from a non-inhibitory down-state to an extended up-state that then inhibits enzymatic ATP hydrolysis by binding to the catalytic domain. It has been demonstrated that the ϵ subunit from Bacillus PS3 is selective for ATP over other nucleotides, including GTP. In this study, the purine triphosphate selectivity is rationalized by using results from MD simulations and free energy calculations for the R103A/R115A mutant of the ϵ subunit from Bacillus PS3, which binds ATP more strongly than the wild-type protein. Our results are in good agreement with experimental data, and the elucidated molecular basis for selectivity could help to guide the design of novel GTP sensors.
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Affiliation(s)
- Alexander Krah
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore.,Korea Institute for Advanced Study, School of Computational Sciences, 85 Hoegiro, Dongdaemun-gu, Seoul, 02455, Republic of Korea
| | - Roland G Huber
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore
| | - Duncan G G McMillan
- Delft University of Technology, Department of Biotechnology, Van der Maasweg 9, Delft, 2629HZ, The Netherlands
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore.,National University of Singapore, Department of Biological Sciences, 14 Science Drive 4, Singapore, 117543, Singapore
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5
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Milgrom YM, Duncan TM. F-ATP-ase of Escherichia coli membranes: The ubiquitous MgADP-inhibited state and the inhibited state induced by the ε-subunit's C-terminal domain are mutually exclusive. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148189. [PMID: 32194063 DOI: 10.1016/j.bbabio.2020.148189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 12/21/2022]
Abstract
ATP synthases are important energy-coupling, rotary motor enzymes in all kingdoms of life. In all F-type ATP synthases, the central rotor of the catalytic F1 complex is composed of the γ subunit and the N-terminal domain (NTD) of the ε subunit. In the enzymes of diverse bacteria, the C-terminal domain of ε (εCTD) can undergo a dramatic conformational change to trap the enzyme in a transiently inactive state. This inhibitory mechanism is absent in the mitochondrial enzyme, so the εCTD could provide a means to selectively target ATP synthases of pathogenic bacteria for antibiotic development. For Escherichia coli and other bacterial model systems, it has been difficult to dissect the relationship between ε inhibition and a MgADP-inhibited state that is ubiquitous for FOF1 from bacteria and eukaryotes. A prior study with the isolated catalytic complex from E. coli, EcF1, showed that these two modes of inhibition are mutually exclusive, but it has long been known that interactions of F1 with the membrane-embedded FO complex modulate inhibition by the εCTD. Here, we study membranes containing EcFOF1 with wild-type ε, ε lacking the full εCTD, or ε with a small deletion at the C-terminus. By using compounds with distinct activating effects on F-ATP-ase activity, we confirm that εCTD inhibition and ubiquitous MgADP inhibition are mutually exclusive for membrane-bound E. coli F-ATP-ase. We determine that most of the enzyme complexes in wild-type membranes are in the ε-inhibited state (>50%) or in the MgADP-inhibited state (30%).
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Affiliation(s)
- Yakov M Milgrom
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA.
| | - Thomas M Duncan
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA.
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6
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Yamakita A, Liu Y, Futai M, Iwamoto-Kihara A. The carboxyl-terminal helical domain of the ATP synthase γ subunit is involved in ε subunit conformation and energy coupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:361-368. [PMID: 30876890 DOI: 10.1016/j.bbabio.2019.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/22/2019] [Accepted: 03/11/2019] [Indexed: 11/26/2022]
Abstract
The γ subunit located at the center of ATP synthase (FOF1) plays critical roles in catalysis. Escherichia coli mutant with Pro substitution of the γ subunit residue γLeu218, which are located the rotor shaft near the c subunit ring, decreased NADH-driven ATP synthesis activity and ATP hydrolysis-dependent H+ transport of membranes to ~60% and ~40% of the wild type, respectively, without affecting FOF1 assembly. Consistently, the mutant was defective in growth by oxidative phosphorylation, indicating that energy coupling is impaired by the mutation. The ε subunit conformations in the γLeu218Pro mutant enzyme were investigated by cross-linking between cysteine residues introduced into both the ε subunit (εCys118 and εCys134, in the second helix and the hook segment, respectively) and the γ subunit (γCys99 and γCys260, located in the globular domain and the carboxyl-terminal helix, respectively). In the presence of ADP, the two γ260 and ε134 cysteine residues formed a disulfide bond in both the γLeu218Pro mutant and the wild type, indicating that the hook segment of ε subunit penetrates into the α3β3-ring along with the γ subunits in both enzymes. However, γ260/ε134 cross-linking in the γLeu218Pro mutant decreased significantly in the presence of ATP, whereas this effect was small in the wild type. These results suggested that the γ subunit carboxyl-terminal helix containing γLeu218 is involved in the conformation of the ε subunit hook region during ATP hydrolysis and, therefore, is required for energy coupling in FOF1.
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Affiliation(s)
- Atsuyoshi Yamakita
- Department of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
| | - YingTao Liu
- Department of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
| | - Masamitsu Futai
- Department of Biochemistry, Faculty of Pharmaceutical Sciences, Iwate Medical University, Yahaba, Iwate 028-3694, Japan
| | - Atsuko Iwamoto-Kihara
- Department of Bioscience, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan.
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7
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Sobti M, Ishmukhametov R, Bouwer JC, Ayer A, Suarna C, Smith NJ, Christie M, Stocker R, Duncan TM, Stewart AG. Cryo-EM reveals distinct conformations of E. coli ATP synthase on exposure to ATP. eLife 2019; 8:e43864. [PMID: 30912741 PMCID: PMC6449082 DOI: 10.7554/elife.43864] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
ATP synthase produces the majority of cellular energy in most cells. We have previously reported cryo-EM maps of autoinhibited E. coli ATP synthase imaged without addition of nucleotide (Sobti et al. 2016), indicating that the subunit ε engages the α, β and γ subunits to lock the enzyme and prevent functional rotation. Here we present multiple cryo-EM reconstructions of the enzyme frozen after the addition of MgATP to identify the changes that occur when this ε inhibition is removed. The maps generated show that, after exposure to MgATP, E. coli ATP synthase adopts a different conformation with a catalytic subunit changing conformation substantially and the ε C-terminal domain transitioning via an intermediate 'half-up' state to a condensed 'down' state. This work provides direct evidence for unique conformational states that occur in E. coli ATP synthase when ATP binding prevents the ε C-terminal domain from entering the inhibitory 'up' state.
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Affiliation(s)
- Meghna Sobti
- Molecular, Structural and Computational Biology DivisionThe Victor Chang Cardiac Research InstituteDarlinghurstAustralia
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
| | - Robert Ishmukhametov
- Department of Physics, Clarendon LaboratoryUniversity of OxfordOxfordUnited Kingdom
| | - James C Bouwer
- Molecular HorizonsThe University of WollongongWollongongAustralia
| | - Anita Ayer
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
- Vascular Biology DivisionVictor Chang Cardiac Research InstituteDarlinghurstAustralia
| | - Cacang Suarna
- Vascular Biology DivisionVictor Chang Cardiac Research InstituteDarlinghurstAustralia
| | - Nicola J Smith
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
- Molecular Cardiology and Biophysics DivisionVictor Chang Cardiac Research InstituteDarlinghurstAustralia
| | - Mary Christie
- Molecular, Structural and Computational Biology DivisionThe Victor Chang Cardiac Research InstituteDarlinghurstAustralia
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
| | - Roland Stocker
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
- Vascular Biology DivisionVictor Chang Cardiac Research InstituteDarlinghurstAustralia
| | - Thomas M Duncan
- Department of Biochemistry & Molecular BiologySUNY Upstate Medical UniversitySyracuse, NYUnited States
| | - Alastair G Stewart
- Molecular, Structural and Computational Biology DivisionThe Victor Chang Cardiac Research InstituteDarlinghurstAustralia
- St Vincent’s Clinical School, Faculty of MedicineUNSW SydneySydneyAustralia
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8
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Sielaff H, Duncan TM, Börsch M. The regulatory subunit ε in Escherichia coli F OF 1-ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:775-788. [PMID: 29932911 DOI: 10.1016/j.bbabio.2018.06.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 11/16/2022]
Abstract
F-type ATP synthases are extraordinary multisubunit proteins that operate as nanomotors. The Escherichia coli (E. coli) enzyme uses the proton motive force (pmf) across the bacterial plasma membrane to drive rotation of the central rotor subunits within a stator subunit complex. Through this mechanical rotation, the rotor coordinates three nucleotide binding sites that sequentially catalyze the synthesis of ATP. Moreover, the enzyme can hydrolyze ATP to turn the rotor in the opposite direction and generate pmf. The direction of net catalysis, i.e. synthesis or hydrolysis of ATP, depends on the cell's bioenergetic conditions. Different control mechanisms have been found for ATP synthases in mitochondria, chloroplasts and bacteria. This review discusses the auto-inhibitory behavior of subunit ε found in FOF1-ATP synthases of many bacteria. We focus on E. coli FOF1-ATP synthase, with insights into the regulatory mechanism of subunit ε arising from structural and biochemical studies complemented by single-molecule microscopy experiments.
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Affiliation(s)
- Hendrik Sielaff
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Thomas M Duncan
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Michael Börsch
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
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9
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Krah A, Zarco-Zavala M, McMillan DGG. Insights into the regulatory function of the ɛ subunit from bacterial F-type ATP synthases: a comparison of structural, biochemical and biophysical data. Open Biol 2018; 8:170275. [PMID: 29769322 PMCID: PMC5990651 DOI: 10.1098/rsob.170275] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/24/2018] [Indexed: 01/07/2023] Open
Abstract
ATP synthases catalyse the formation of ATP, the most common chemical energy storage unit found in living cells. These enzymes are driven by an electrochemical ion gradient, which allows the catalytic evolution of ATP by a binding change mechanism. Most ATP synthases are capable of catalysing ATP hydrolysis to varying degrees, and to prevent wasteful ATP hydrolysis, bacteria and mitochondria have regulatory mechanisms such as ADP inhibition. Additionally, ɛ subunit inhibition has also been described in three bacterial systems, Escherichia coli, Bacillus PS3 and Caldalkalibacillus thermarum TA2.A1. Previous studies suggest that the ɛ subunit is capable of undergoing an ATP-dependent conformational change from the ATP hydrolytic inhibitory 'extended' conformation to the ATP-induced non-inhibitory 'hairpin' conformation. A recently published crystal structure of the F1 domain of the C. thermarum TA2.A1 F1Fo ATP synthase revealed a mutant ɛ subunit lacking the ability to bind ATP in a hairpin conformation. This is a surprising observation considering it is an organism that performs no ATP hydrolysis in vivo, and appears to challenge the current dogma on the regulatory role of the ɛ subunit. This has prompted a re-examination of present knowledge of the ɛ subunits role in different organisms. Here, we compare published biochemical, biophysical and structural data involving ɛ subunit-mediated ATP hydrolysis regulation in a variety of organisms, concluding that the ɛ subunit from the bacterial F-type ATP synthases is indeed capable of regulating ATP hydrolysis activity in a wide variety of bacteria, making it a potentially valuable drug target, but its exact role is still under debate.
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Affiliation(s)
- Alexander Krah
- School of Computational Sciences, Korea Institute for Advanced Study, 85 Hoegiro Dongdaemun-gu, Seoul 02455, Republic of Korea
| | - Mariel Zarco-Zavala
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Duncan G G McMillan
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, Delft 2629 HZ, The Netherlands
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10
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Sekiya M, Sakamoto Y, Futai M, Nakanishi-Matsui M. Role of α/β interface in F 1 ATPase rotational catalysis probed by inhibitors and mutations. Int J Biol Macromol 2017; 99:615-621. [DOI: 10.1016/j.ijbiomac.2017.02.089] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/24/2017] [Indexed: 01/26/2023]
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11
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Singh D, Sielaff H, Börsch M, Grüber G. Conformational dynamics of the rotary subunit F in the A 3 B 3 DF complex of Methanosarcina mazei Gö1 A-ATP synthase monitored by single-molecule FRET. FEBS Lett 2017; 591:854-862. [PMID: 28231387 DOI: 10.1002/1873-3468.12605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/13/2017] [Accepted: 02/16/2017] [Indexed: 12/28/2022]
Abstract
In archaea the A1 AO ATP synthase uses a transmembrane electrochemical potential to generate ATP, while the soluble A1 domain (subunits A3 B3 DF) alone can hydrolyse ATP. The three nucleotide-binding AB pairs form a barrel-like structure with a central orifice that hosts the rotating central stalk subunits DF. ATP binding, hydrolysis and product release cause a conformational change inside the A:B-interface, which enforces the rotation of subunits DF. Recently, we reported that subunit F is a stimulator of ATPase activity. Here, we investigated the nucleotide-dependent conformational changes of subunit F relative to subunit D during ATP hydrolysis in the A3 B3 DF complex of the Methanosarcina mazei Gö1 A-ATP synthase using single-molecule Förster resonance energy transfer. We found two conformations for subunit F during ATP hydrolysis.
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Affiliation(s)
- Dhirendra Singh
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Hendrik Sielaff
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.,Single-Molecule Microscopy Group, Jena University Hospital, Germany
| | - Michael Börsch
- Single-Molecule Microscopy Group, Jena University Hospital, Germany
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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12
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Nakanishi-Matsui M, Sekiya M, Futai M. ATP synthase from Escherichia coli : Mechanism of rotational catalysis, and inhibition with the ε subunit and phytopolyphenols. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:129-140. [DOI: 10.1016/j.bbabio.2015.11.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/19/2015] [Accepted: 11/13/2015] [Indexed: 10/22/2022]
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13
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Singh D, Sielaff H, Sundararaman L, Bhushan S, Grüber G. The stimulating role of subunit F in ATPase activity inside the A1-complex of the Methanosarcina mazei Gö1 A1AO ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1857:177-187. [PMID: 26682760 DOI: 10.1016/j.bbabio.2015.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/19/2015] [Accepted: 12/03/2015] [Indexed: 10/22/2022]
Abstract
A1AO ATP synthases couple ion-transport of the AO sector and ATP synthesis/hydrolysis of the A3B3-headpiece via their stalk subunits D and F. Here, we produced and purified stable A3B3D- and A3B3DF-complexes of the Methanosarcina mazei Gö1 A-ATP synthase as confirmed by electron microscopy. Enzymatic studies with these complexes showed that the M. mazei Gö1 A-ATP synthase subunit F is an ATPase activating subunit. The maximum ATP hydrolysis rates (Vmax) of A3B3D and A3B3DF were determined by substrate-dependent ATP hydrolysis experiments resulting in a Vmax of 7.9 s(-1) and 30.4 s(-1), respectively, while the KM is the same for both. Deletions of the N- or C-termini of subunit F abolished the effect of ATP hydrolysis activation. We generated subunit F mutant proteins with single amino acid substitutions and demonstrated that the subunit F residues S84 and R88 are important in stimulating ATP hydrolysis. Hybrid formation of the A3B3D-complex with subunit F of the related eukaryotic V-ATPase of Saccharomyces cerevisiae or subunit ε of the F-ATP synthase from Mycobacterium tuberculosis showed that subunit F of the archaea and eukaryotic enzymes are important in ATP hydrolysis.
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Affiliation(s)
- Dhirendra Singh
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Hendrik Sielaff
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Lavanya Sundararaman
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Shashi Bhushan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
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14
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Shirakihara Y, Shiratori A, Tanikawa H, Nakasako M, Yoshida M, Suzuki T. Structure of a thermophilic F1-ATPase inhibited by an ε-subunit: deeper insight into the ε-inhibition mechanism. FEBS J 2015; 282:2895-913. [PMID: 26032434 DOI: 10.1111/febs.13329] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 05/19/2015] [Accepted: 05/26/2015] [Indexed: 11/28/2022]
Abstract
F1-ATPase (F1) is the catalytic sector in F(o)F1-ATP synthase that is responsible for ATP production in living cells. In catalysis, its three catalytic β-subunits undergo nucleotide occupancy-dependent and concerted open-close conformational changes that are accompanied by rotation of the γ-subunit. Bacterial and chloroplast F1 are inhibited by their own ε-subunit. In the ε-inhibited Escherichia coli F1 structure, the ε-subunit stabilizes the overall conformation (half-closed, closed, open) of the β-subunits by inserting its C-terminal helix into the α3β3 cavity. The structure of ε-inhibited thermophilic F1 is similar to that of E. coli F1, showing a similar conformation of the ε-subunit, but the thermophilic ε-subunit stabilizes another unique overall conformation (open, closed, open) of the β-subunits. The ε-C-terminal helix 2 and hook are conserved between the two structures in interactions with target residues and in their positions. Rest of the ε-C-terminal domains are in quite different conformations and positions, and have different modes of interaction with targets. This region is thought to serve ε-inhibition differently. For inhibition, the ε-subunit contacts the second catches of some of the β- and α-subunits, the N- and C-terminal helices, and some of the Rossmann fold segments. Those contacts, as a whole, lead to positioning of those β- and α- second catches in ε-inhibition-specific positions, and prevent rotation of the γ-subunit. Some of the structural features are observed even in IF1 inhibition in mitochondrial F1.
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Affiliation(s)
| | | | | | - Masayoshi Nakasako
- The Institute of Molecular and Cellular Biosciences, The University of Tokyo, Japan
| | - Masasuke Yoshida
- The Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, Japan.,ERATO, Japan Science and Technology Corporation (JST), Yokohama, Japan
| | - Toshiharu Suzuki
- The Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama, Japan.,ERATO, Japan Science and Technology Corporation (JST), Yokohama, Japan
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