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Functional importance of αAsp-350 in the catalytic sites of Escherichia coli ATP synthase. Arch Biochem Biophys 2019; 672:108050. [PMID: 31330132 DOI: 10.1016/j.abb.2019.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/10/2019] [Accepted: 07/18/2019] [Indexed: 12/21/2022]
Abstract
Negatively charged residue αAsp-350 of the highly conserved VISIT-DG sequence is required for Pi binding and maintenance of the phosphate-binding subdomain in the catalytic sites of Escherichia coli F1Fo ATP synthase. αAsp-350 is situated in close proximity, 2.88 Å and 3.5 Å, to the conserved known phosphate-binding residues αR376 and βR182. αD350 is also in close proximity, 1.3 Å, to another functionally important residue αG351. Mutation of αAsp-350 to Ala, Gln, or Arg resulted in substantial loss of oxidative phosphorylation and reduction in ATPase activity by 6- to 16-fold. The loss of the acidic side chain in the form of αD350A, αD350Q, and αD350R caused loss of Pi binding. While removal of Arg in the form of αR376D resulted in the loss of Pi binding, the addition of Arg in the form of αG351R did not affect Pi binding. Our data demonstrates that αD350R helps in the proper orientation of αR376 and βR182 for Pi binding. Fluoroaluminate, fluoroscandium, and sodium azide caused almost complete inhibition of wild type enzyme and caused variable inhibition of αD350 mutant enzymes. NBD-Cl (4-chloro-7-nitrobenzo-2-oxa-1, 3-diazole) caused complete inhibition of wild type enzyme while some residual activity was left in mutant enzymes. Inhibition characteristics supported the conclusion that NBD-Cl reacts in βE (empty) catalytic sites. Phosphate protected against NBD-Cl inhibition of wild type and αG351R mutant enzymes but not inhibition of αD350A, αD350Q, αD350R, or αR376D mutant enzymes. These results demonstrate that αAsp-350 is an essential residue required for phosphate binding, through its interaction with αR376 and βR182, for normal function of phosphate binding subdomain and for transition state stabilization in ATP synthase catalytic sites.
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Flagella-Driven Motility of Bacteria. Biomolecules 2019; 9:biom9070279. [PMID: 31337100 PMCID: PMC6680979 DOI: 10.3390/biom9070279] [Citation(s) in RCA: 181] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 01/17/2023] Open
Abstract
The bacterial flagellum is a helical filamentous organelle responsible for motility. In bacterial species possessing flagella at the cell exterior, the long helical flagellar filament acts as a molecular screw to generate thrust. Meanwhile, the flagella of spirochetes reside within the periplasmic space and not only act as a cytoskeleton to determine the helicity of the cell body, but also rotate or undulate the helical cell body for propulsion. Despite structural diversity of the flagella among bacterial species, flagellated bacteria share a common rotary nanomachine, namely the flagellar motor, which is located at the base of the filament. The flagellar motor is composed of a rotor ring complex and multiple transmembrane stator units and converts the ion flux through an ion channel of each stator unit into the mechanical work required for motor rotation. Intracellular chemotactic signaling pathways regulate the direction of flagella-driven motility in response to changes in the environments, allowing bacteria to migrate towards more desirable environments for their survival. Recent experimental and theoretical studies have been deepening our understanding of the molecular mechanisms of the flagellar motor. In this review article, we describe the current understanding of the structure and dynamics of the bacterial flagellum.
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53
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Essential Role of the ε Subunit for Reversible Chemo-Mechanical Coupling in F 1-ATPase. Biophys J 2019; 114:178-187. [PMID: 29320685 DOI: 10.1016/j.bpj.2017.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/31/2017] [Accepted: 11/06/2017] [Indexed: 11/22/2022] Open
Abstract
F1-ATPase is a rotary motor protein driven by ATP hydrolysis. Among molecular motors, F1 exhibits unique high reversibility in chemo-mechanical coupling, synthesizing ATP from ADP and inorganic phosphate upon forcible rotor reversal. The ε subunit enhances ATP synthesis coupling efficiency to > 70% upon rotation reversal. However, the detailed mechanism has remained elusive. In this study, we performed stall-and-release experiments to elucidate how the ε subunit modulates ATP association/dissociation and hydrolysis/synthesis process kinetics and thermodynamics, key reaction steps for efficient ATP synthesis. The ε subunit significantly accelerated the rates of ATP dissociation and synthesis by two- to fivefold, whereas those of ATP binding and hydrolysis were not enhanced. Numerical analysis based on the determined kinetic parameters quantitatively reproduced previous findings of two- to fivefold coupling efficiency improvement by the ε subunit at the condition exhibiting the maximum ATP synthesis activity, a physiological role of F1-ATPase. Furthermore, fundamentally similar results were obtained upon ε subunit C-terminal domain truncation, suggesting that the N-terminal domain is responsible for the rate enhancement.
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Iwata S, Kinosita Y, Uchida N, Nakane D, Nishizaka T. Motor torque measurement of Halobacterium salinarum archaellar suggests a general model for ATP-driven rotary motors. Commun Biol 2019; 2:199. [PMID: 31149643 PMCID: PMC6534597 DOI: 10.1038/s42003-019-0422-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Accepted: 04/05/2019] [Indexed: 02/06/2023] Open
Abstract
It is unknown how the archaellum-the rotary propeller used by Archaea for motility-works. To further understand the molecular mechanism by which the hexameric ATPase motor protein FlaI drives rotation of the membrane-embedded archaellar motor, we determined motor torque by imposition of various loads on Halobacterium salinarum archaella. Markers of different sizes were attached to single archaella, and their trajectories were quantified using three-dimensional tracking and high-speed recording. We show that rotation slows as the viscous drag of markers increases, but torque remains constant at 160 pN·nm independent of rotation speed. Notably, the estimated work done in a single rotation is twice the expected energy that would come from hydrolysis of six ATP molecules in the hexamer, indicating that more ATP molecules are required for one rotation of archaellum. To reconcile the apparent contradiction, we suggest a new and general model for the mechanism of ATP-driven rotary motors.
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Affiliation(s)
- Seiji Iwata
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 Japan
| | - Yoshiaki Kinosita
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 Japan
| | - Nariya Uchida
- Department of Physics, Tohoku University, Sendai, 980-8578 Japan
| | - Daisuke Nakane
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 Japan
| | - Takayuki Nishizaka
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588 Japan
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55
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Single-molecule pull-out manipulation of the shaft of the rotary motor F 1-ATPase. Sci Rep 2019; 9:7451. [PMID: 31092848 PMCID: PMC6520343 DOI: 10.1038/s41598-019-43903-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 04/29/2019] [Indexed: 01/29/2023] Open
Abstract
F1-ATPase is a rotary motor protein in which the central γ-subunit rotates inside the cylinder made of α3β3 subunits. To investigate interactions between the γ shaft and the cylinder at the molecular scale, load was imposed on γ through a polystyrene bead by three-dimensional optical trapping in the direction along which the shaft penetrates the cylinder. Pull-out event was observed under high-load, and thus load-dependency of lifetime of the interaction was estimated. Notably, accumulated counts of lifetime were comprised of fast and slow components. Both components exponentially dropped with imposed loads, suggesting that the binding energy is compensated by the work done by optical trapping. Because the mutant, in which the half of the shaft was deleted, showed only one fast component in the bond lifetime, the slow component is likely due to the native interaction mode held by multiple interfaces.
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56
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Yokota H. Fluorescence microscopy for visualizing single-molecule protein dynamics. Biochim Biophys Acta Gen Subj 2019; 1864:129362. [PMID: 31078674 DOI: 10.1016/j.bbagen.2019.05.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 04/26/2019] [Accepted: 05/07/2019] [Indexed: 01/06/2023]
Abstract
BACKGROUND Single-molecule fluorescence imaging (smFI) has evolved into a valuable method used in biophysical and biochemical studies as it can observe the real-time behavior of individual protein molecules, enabling understanding of their detailed dynamic features. smFI is also closely related to other state-of-the-art microscopic methods, optics, and nanomaterials in that smFI and these technologies have developed synergistically. SCOPE OF REVIEW This paper provides an overview of the recently developed single-molecule fluorescence microscopy methods, focusing on critical techniques employed in higher-precision measurements in vitro and fluorescent nanodiamond, an emerging promising fluorophore that will improve single-molecule fluorescence microscopy. MAJOR CONCLUSIONS smFI will continue to improve regarding the photostability of fluorophores and will develop via combination with other techniques based on nanofabrication, single-molecule manipulation, and so on. GENERAL SIGNIFICANCE Quantitative, high-resolution single-molecule studies will help establish an understanding of protein dynamics and complex biomolecular systems.
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Affiliation(s)
- Hiroaki Yokota
- Biophotonics Laboratory, Graduate School for the Creation of New Photonics Industries, Kurematsu-cho, Nishi-ku, Hamamatsu, Shizuoka 431-1202, Japan.
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57
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Sumi T, Klumpp S. Is F 1-ATPase a Rotary Motor with Nearly 100% Efficiency? Quantitative Analysis of Chemomechanical Coupling and Mechanical Slip. NANO LETTERS 2019; 19:3370-3378. [PMID: 31017791 DOI: 10.1021/acs.nanolett.9b01181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present a chemomechanical network model of the rotary molecular motor F1-ATPase which quantitatively describes not only the rotary motor dynamics driven by ATP hydrolysis but also the ATP synthesis caused by forced reverse rotations. We observe a high reversibility of F1-ATPase, that is, the main cycle of ATP synthesis corresponds to the reversal of the main cycle in the hydrolysis-driven motor rotation. However, our quantitative analysis indicates that torque-induced mechanical slip without chemomechanical coupling occurs under high external torque and reduces the maximal efficiency of the free energy transduction to 40-80% below the optimal efficiency. Heat irreversibly dissipates not only through the viscous friction of the probe but also directly from the motor due to torque-induced mechanical slip. Such irreversible heat dissipation is a crucial limitation for achieving a 100% free-energy transduction efficiency with biological nanomachines because biomolecules are easily deformed by external torque.
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Affiliation(s)
| | - Stefan Klumpp
- Institute for the Dynamics of Complex Systems , University of Göttingen , Friedrich-Hund-Platz 1 , 37077 Göttingen , Germany
- Department Theory and Bio-Systems , Max Planck Institute of Colloids and Interfaces , 14424 Potsdam , Germany
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58
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Fu L, Wang H, Li H. Harvesting Mechanical Work From Folding-Based Protein Engines: From Single-Molecule Mechanochemical Cycles to Macroscopic Devices. CCS CHEMISTRY 2019. [DOI: 10.31635/ccschem.019.20180012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Mechanochemical coupling cycles underlie the work-generation mechanisms of biological systems and are realized by highly regulated conformational changes of the protein machineries. However, it has been challenging to utilize protein conformational changes to do mechanical work at the macroscopic level in biomaterials, and it remains elusive to construct macroscopic mechanochemical devices based on molecular-level mechanochemical coupling systems. Here, the authors demonstrate that protein folding can be utilized to realize protein’s mechanochemical cycles at both single-molecule and macroscopic levels. Our results demonstrate, for the first time, the successful harnessing of mechanical work generated by protein folding in a macroscopic protein hydrogel device, and the work generated by protein folding compares favorably with the energy output of molecular motors. Our work bridges a gap between single-molecule and macroscopic levels, and paves the way to utilizing proteins as building blocks to design protein-based artificial muscles and soft actuators.
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59
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Trombetti F, Pagliarani A, Ventrella V, Algieri C, Nesci S. Crucial aminoacids in the F O sector of the F 1F O-ATP synthase address H + across the inner mitochondrial membrane: molecular implications in mitochondrial dysfunctions. Amino Acids 2019; 51:579-587. [PMID: 30798467 DOI: 10.1007/s00726-019-02710-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 02/09/2019] [Indexed: 12/14/2022]
Abstract
The eukaryotic F1FO-ATP synthase/hydrolase activity is coupled to H+ translocation through the inner mitochondrial membrane. According to a recent model, two asymmetric H+ half-channels in the a subunit translate a transmembrane vertical H+ flux into the rotor rotation required for ATP synthesis/hydrolysis. Along the H+ pathway, conserved aminoacid residues, mainly glutamate, address H+ both in the downhill and uphill transmembrane movements to synthesize or hydrolyze ATP, respectively. Point mutations responsible for these aminoacid changes affect H+ transfer through the membrane and, as a cascade, result in mitochondrial dysfunctions and related pathologies. The involvement of specific aminoacid residues in driving H+ along their transmembrane pathway within a subunit, sustained by the literature and calculated data, leads to depict a model consistent with some mitochondrial disorders.
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Affiliation(s)
- Fabiana Trombetti
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Alessandra Pagliarani
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy.
| | - Vittoria Ventrella
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Cristina Algieri
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
| | - Salvatore Nesci
- Department of Veterinary Medical Sciences, University of Bologna, Via Tolara di Sopra 50, 40064, Ozzano Emilia, BO, Italy
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60
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Sielaff H, Yanagisawa S, Frasch WD, Junge W, Börsch M. Structural Asymmetry and Kinetic Limping of Single Rotary F-ATP Synthases. Molecules 2019; 24:E504. [PMID: 30704145 PMCID: PMC6384691 DOI: 10.3390/molecules24030504] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/23/2019] [Accepted: 01/29/2019] [Indexed: 12/12/2022] Open
Abstract
F-ATP synthases use proton flow through the FO domain to synthesize ATP in the F₁ domain. In Escherichia coli, the enzyme consists of rotor subunits γεc10 and stator subunits (αβ)₃δab₂. Subunits c10 or (αβ)₃ alone are rotationally symmetric. However, symmetry is broken by the b₂ homodimer, which together with subunit δa, forms a single eccentric stalk connecting the membrane embedded FO domain with the soluble F₁ domain, and the central rotating and curved stalk composed of subunit γε. Although each of the three catalytic binding sites in (αβ)₃ catalyzes the same set of partial reactions in the time average, they might not be fully equivalent at any moment, because the structural symmetry is broken by contact with b₂δ in F₁ and with b₂a in FO. We monitored the enzyme's rotary progression during ATP hydrolysis by three single-molecule techniques: fluorescence video-microscopy with attached actin filaments, Förster resonance energy transfer between pairs of fluorescence probes, and a polarization assay using gold nanorods. We found that one dwell in the three-stepped rotary progression lasting longer than the other two by a factor of up to 1.6. This effect of the structural asymmetry is small due to the internal elastic coupling.
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Affiliation(s)
- Hendrik Sielaff
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, 07743 Jena, Germany.
| | - Seiga Yanagisawa
- School of Life Sciences, Arizona State University, Tempe, Arizona, AZ 85287, USA.
| | - Wayne D Frasch
- School of Life Sciences, Arizona State University, Tempe, Arizona, AZ 85287, USA.
| | - Wolfgang Junge
- Department of Biology & Chemistry, University of Osnabrück, 49076 Osnabrück, Germany.
| | - Michael Börsch
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, 07743 Jena, Germany.
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61
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Fujimoto K, Morita Y, Iino R, Tomishige M, Shintaku H, Kotera H, Yokokawa R. Simultaneous Observation of Kinesin-Driven Microtubule Motility and Binding of Adenosine Triphosphate Using Linear Zero-Mode Waveguides. ACS NANO 2018; 12:11975-11985. [PMID: 30418736 DOI: 10.1021/acsnano.8b03803] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Single-molecule fluorescence observation of adenosine triphosphate (ATP) is a powerful tool to elucidate the chemomechanical coupling of ATP with a motor protein. However, in total internal reflection fluorescence microscopy (TIRFM), available ATP concentration is much lower than that in the in vivo environment. To achieve single-molecule observation with a high signal-to-noise ratio, zero-mode waveguides (ZMWs) are utilized even at high fluorescent molecule concentrations in the micromolar range. Despite the advantages of ZMWs, the use of cytoskeletal filaments for single-molecule observation has not been reported because of difficulties in immobilization of cytoskeletal filaments in the cylindrical aperture of ZMWs. Here, we propose linear ZMWs (LZMWs) to visualize enzymatic reactions on cytoskeletal filaments, specifically kinesin-driven microtubule motility accompanied by ATP binding/unbinding. Finite element method simulation revealed excitation light confinement in a 100 nm wide slit of LZMWs. Single-molecule observation was then demonstrated with up to 1 μM labeled ATP, which was 10-fold higher than that available in TIRFM. Direct observation of binding/unbinding of ATP to kinesins that propel microtubules enabled us to find that a significant fraction of ATP molecules bound to kinesins were dissociated without hydrolysis. This highlights the advantages of LZMWs for single-molecule observation of proteins that interact with cytoskeletal filaments such as microtubules, actin filaments, or intermediate filaments.
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Affiliation(s)
- Kazuya Fujimoto
- Department of Micro Engineering , Kyoto University , Kyoto 615-8540 , Japan
| | - Yuki Morita
- Department of Micro Engineering , Kyoto University , Kyoto 615-8540 , Japan
| | - Ryota Iino
- Institute for Molecular Science , National Institutes of Natural Sciences , Okazaki , Aichi 444-8787 , Japan
| | - Michio Tomishige
- College of Science and Engineering , Aoyama Gakuin University , Kanagawa 252-5258 , Japan
| | - Hirofumi Shintaku
- Department of Micro Engineering , Kyoto University , Kyoto 615-8540 , Japan
| | - Hidetoshi Kotera
- Department of Micro Engineering , Kyoto University , Kyoto 615-8540 , Japan
| | - Ryuji Yokokawa
- Department of Micro Engineering , Kyoto University , Kyoto 615-8540 , Japan
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62
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Mnatsakanyan N, Li Y, Weber J. Identification of two segments of the γ subunit of ATP synthase responsible for the different affinities of the catalytic nucleotide-binding sites. J Biol Chem 2018; 294:1152-1160. [PMID: 30510135 DOI: 10.1074/jbc.ra118.002504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 11/26/2018] [Indexed: 11/06/2022] Open
Abstract
ATP synthase uses a rotary mechanism to couple transmembrane proton translocation to ATP synthesis and hydrolysis, which occur at the catalytic sites in the β subunits. In the presence of Mg2+, the three catalytic sites of ATP synthase have vastly different affinities for nucleotides, and the position of the central γ subunit determines which site has high, medium, or low affinity. Affinity differences and their changes as rotation progresses underpin the ATP synthase catalytic mechanism. Here, we used a series of variants with up to 45- and 60-residue-long truncations of the N- and C-terminal helices of the γ subunit, respectively, to identify the segment(s) responsible for the affinity differences of the catalytic sites. We found that each helix carries an affinity-determining segment of ∼10 residues. Our findings suggest that the affinity regulation by these segments is transmitted to the catalytic sites by the DELSEED loop in the C-terminal domain of the β subunits. For the N-terminal truncation variants, presence of the affinity-determining segment and therefore emergence of a high-affinity binding site resulted in WT-like catalytic activity. At the C terminus, additional residues outside of the affinity-determining segment were required for optimal enzymatic activity. Alanine substitutions revealed that the affinity changes of the catalytic sites required no specific interactions between amino acid side chains in the γ and α3β3 subunits but were caused by the presence of the helices themselves. Our findings help unravel the molecular basis for the affinity changes of the catalytic sites during ATP synthase rotation.
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Affiliation(s)
- Nelli Mnatsakanyan
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 and the Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430
| | - Yunxiang Li
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 and the Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430
| | - Joachim Weber
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409 and the Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, Texas 79430.
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63
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Murcia Rios A, Vahidi S, Dunn SD, Konermann L. Evidence for a Partially Stalled γ Rotor in F 1-ATPase from Hydrogen-Deuterium Exchange Experiments and Molecular Dynamics Simulations. J Am Chem Soc 2018; 140:14860-14869. [PMID: 30339028 DOI: 10.1021/jacs.8b08692] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
F1-ATPase uses ATP hydrolysis to drive rotation of the γ subunit. The γ C-terminal helix constitutes the rotor tip that is seated in an apical bearing formed by α3β3. It remains uncertain to what extent the γ conformation during rotation differs from that seen in rigid crystal structures. Existing models assume that the entire γ subunit participates in every rotation. Here we interrogated E. coli F1-ATPase by hydrogen-deuterium exchange (HDX) mass spectrometry. Rotation of γ caused greatly enhanced deuteration in the γ C-terminal helix. The HDX kinetics implied that most F1 complexes operate with an intact rotor at any given time, but that the rotor tip is prone to occasional unfolding. A molecular dynamics (MD) strategy was developed to model the off-axis forces acting on γ. MD runs showed stalling of the rotor tip and unfolding of the γ C-terminal helix. MD-predicted H-bond opening events coincided with experimental HDX patterns. Our data suggest that in vitro operation of F1-ATPase is associated with significant rotational resistance in the apical bearing. These conditions cause the γ C-terminal helix to get "stuck" (and unfold) sporadically while the remainder of γ continues to rotate. This scenario contrasts the traditional "greasy bearing" model that envisions smooth rotation of the γ C-terminal helix. The fragility of the apical rotor tip in F1-ATPase is attributed to the absence of a c10 ring that stabilizes the rotation axis in intact FoF1. Overall, the MD/HDX strategy introduced here appears well suited for interrogating the inner workings of molecular motors.
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Affiliation(s)
- Angela Murcia Rios
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Siavash Vahidi
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Stanley D Dunn
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
| | - Lars Konermann
- Departments of Chemistry and Biochemistry , The University of Western Ontario , London , Ontario N6A 5B7 , Canada
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64
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Nord AL, Pols AF, Depken M, Pedaci F. Kinetic analysis methods applied to single motor protein trajectories. Phys Chem Chem Phys 2018; 20:18775-18781. [PMID: 29961801 DOI: 10.1039/c8cp03056a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular motors convert chemical or electrical energy into mechanical displacement, either linear or rotary. Under ideal circumstances, single-molecule measurements can spatially and temporally resolve individual steps of the motor, revealing important properties of the underlying mechanochemical process. Unfortunately, steps are often hard to resolve, as they are masked by thermal noise. In such cases, details of the mechanochemistry can nonetheless be recovered by analyzing the fluctuations in the recorded traces. Here, we expand upon existing statistical analysis methods, providing two new avenues to extract the motor step size, the effective number of rate-limiting chemical states per translocation step, and the compliance of the link between the motor and the probe particle. We first demonstrate the power and limitations of these methods using simulated molecular motor trajectories, and we then apply these methods to experimental data of kinesin, the bacterial flagellar motor, and F1-ATPase.
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Affiliation(s)
- A L Nord
- CBS, Univ. Montpellier, CNRS, INSERM, Montpellier, France.
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65
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Elastic coupling power stroke mechanism of the F 1-ATPase molecular motor. Proc Natl Acad Sci U S A 2018; 115:5750-5755. [PMID: 29760063 PMCID: PMC5984535 DOI: 10.1073/pnas.1803147115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The angular velocity profile of the 120° F1-ATPase power stroke was resolved as a function of temperature from 16.3 to 44.6 °C using a ΔμATP = -31.25 kBT at a time resolution of 10 μs. Angular velocities during the first 60° of the power stroke (phase 1) varied inversely with temperature, resulting in negative activation energies with a parabolic dependence. This is direct evidence that phase 1 rotation derives from elastic energy (spring constant, κ = 50 kBT·rad-2). Phase 2 of the power stroke had an enthalpic component indicating that additional energy input occurred to enable the γ-subunit to overcome energy stored by the spring after rotating beyond its 34° equilibrium position. The correlation between the probability distribution of ATP binding to the empty catalytic site and the negative Ea values of the power stroke during phase 1 suggests that this additional energy is derived from the binding of ATP to the empty catalytic site. A second torsion spring (κ = 150 kBT·rad-2; equilibrium position, 90°) was also evident that mitigated the enthalpic cost of phase 2 rotation. The maximum ΔGǂ was 22.6 kBT, and maximum efficiency was 72%. An elastic coupling mechanism is proposed that uses the coiled-coil domain of the γ-subunit rotor as a torsion spring during phase 1, and then as a crankshaft driven by ATP-binding-dependent conformational changes during phase 2 to drive the power stroke.
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66
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Basu A, Hobson M, Lebel P, Fernandes LE, Tretter EM, Berger JM, Bryant Z. Dynamic coupling between conformations and nucleotide states in DNA gyrase. Nat Chem Biol 2018; 14:565-574. [PMID: 29662209 PMCID: PMC10121156 DOI: 10.1038/s41589-018-0037-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Accepted: 02/21/2018] [Indexed: 11/09/2022]
Abstract
Gyrase is an essential bacterial molecular motor that supercoils DNA using a conformational cycle in which chiral wrapping of > 100 base pairs confers directionality on topoisomerization. To understand the mechanism of this nucleoprotein machine, global structural transitions must be mapped onto the nucleotide cycle of ATP binding, hydrolysis and product release. Here we investigate coupling mechanisms using single-molecule tracking of DNA rotation and contraction during Escherichia coli gyrase activity under varying nucleotide conditions. We find that ADP must be exchanged for ATP to drive the rate-limiting remodeling transition that generates the chiral wrap. ATP hydrolysis accelerates subsequent duplex strand passage and is required for resetting the enzyme and recapturing transiently released DNA. Our measurements suggest how gyrase coordinates DNA rearrangements with the dynamics of its ATP-driven protein gate, how the motor minimizes futile cycles of ATP hydrolysis and how gyrase may respond to changing cellular energy levels to link gene expression with metabolism.
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Affiliation(s)
- Aakash Basu
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Matthew Hobson
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Program in Molecular Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Paul Lebel
- Department of Applied Physics, Stanford University, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Louis E Fernandes
- Department of Bioengineering, Stanford University, Stanford, CA, USA.,Program in Biophysics, Stanford University, Stanford, CA, USA.,Tempus, Inc., Chicago, IL, USA
| | - Elsa M Tretter
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.,Nurix Inc., San Francisco, CA, USA
| | - James M Berger
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Zev Bryant
- Department of Bioengineering, Stanford University, Stanford, CA, USA. .,Department of Structural Biology, Stanford University Medical Center, Stanford, CA, USA.
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67
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What can be learned about the enzyme ATPase from single-molecule studies of its subunit F1? Q Rev Biophys 2018; 50:e14. [PMID: 29233226 DOI: 10.1017/s0033583517000129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We summarize the different types of single molecule experiments on the F1 component of FOF1-ATP Synthase and what has been learned from them. We also describe results from our recent studies on interpreting the experiments using a chemical-mechanical theory for these biological motors.
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68
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Tamiya Y, Watanabe R, Noji H, Li CB, Komatsuzaki T. Effects of non-equilibrium angle fluctuation on F 1-ATPase kinetics induced by temperature increase. Phys Chem Chem Phys 2018; 20:1872-1880. [PMID: 29292807 DOI: 10.1039/c7cp06256g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
F1-ATPase (F1) is an efficient rotary protein motor, whose reactivity is modulated by the rotary angle to utilize thermal fluctuation. In order to elucidate how its kinetics are affected by the change in the fluctuation, we have extended the reaction-diffusion formalism [R. Watanabe et al., Biophys. J., 2013, 105, 2385] applicable to a wider range of temperatures based on experimental data analysis of F1 derived from thermophilic Bacillus under high ATP concentration conditions. Our simulation shows that the rotary angle distribution manifests a stronger non-equilibrium feature as the temperature increases, because ATP hydrolysis and Pi release are more accelerated compared with the timescale of rotary angle relaxation. This effect causes the rate coefficient obtained from dwell time fitting to deviate from the Arrhenius relation in Pi release, which has been assumed in the previous activation thermodynamic quantities estimation using linear Arrhenius fitting. Larger negative correlation is also found between hydrolysis and Pi release waiting time in a catalytic dwell with the increase in temperature. This loss of independence between the two successive reactions at the catalytic dwell sheds doubt on the conventional dwell time fitting to obtain rate coefficients with a double exponential function at temperatures higher than 65 °C, which is close to the physiological temperature of the thermophilic Bacillus.
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Affiliation(s)
- Yuji Tamiya
- Department of Mathematics, Hokkaido University, Sapporo 001-0020, Japan
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69
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Kondo K, Takeyama Y, Sunamura EI, Madoka Y, Fukaya Y, Isu A, Hisabori T. Amputation of a C-terminal helix of the γ subunit increases ATP-hydrolysis activity of cyanobacterial F 1 ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:319-325. [PMID: 29470949 DOI: 10.1016/j.bbabio.2018.02.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 02/09/2018] [Accepted: 02/14/2018] [Indexed: 12/01/2022]
Abstract
F1 is a soluble part of FoF1-ATP synthase and performs a catalytic process of ATP hydrolysis and synthesis. The γ subunit, which is the rotary shaft of F1 motor, is composed of N-terminal and C-terminal helices domains, and a protruding Rossman-fold domain located between the two major helices parts. The N-terminal and C-terminal helices domains of γ assemble into an antiparallel coiled-coil structure, and are almost embedded into the stator ring composed of α3β3 hexamer of the F1 molecule. Cyanobacterial and chloroplast γ subunits harbor an inserted sequence of 30 or 39 amino acids length within the Rossman-fold domain in comparison with bacterial or mitochondrial γ. To understand the structure-function relationship of the γ subunit, we prepared a mutant F1-ATP synthase of a thermophilic cyanobacterium, Thermosynechococcus elongatus BP-1, in which the γ subunit is split into N-terminal α-helix along with the inserted sequence and the remaining C-terminal part. The obtained mutant showed higher ATP-hydrolysis activities than those containing the wild-type γ. Contrary to our expectation, the complexes containing the split γ subunits were mostly devoid of the C-terminal helix. We further investigated the effect of post-assembly cleavage of the γ subunit. We demonstrate that insertion of the nick between two helices of the γ subunit imparts resistance to ADP inhibition, and the C-terminal α-helix is dispensable for ATP-hydrolysis activity and plays a crucial role in the assembly of F1-ATP synthase.
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Affiliation(s)
- Kumiko Kondo
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo 102-0075, Japan
| | - Yu Takeyama
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan
| | - Ei-Ichiro Sunamura
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo 102-0075, Japan
| | - Yuka Madoka
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo 102-0075, Japan
| | - Yuki Fukaya
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan
| | - Atsuko Isu
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo 102-0075, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Tokyo Institute of Technology, Nagatsuta 4259-R1-8, Midori-Ku, Yokohama 226-8503, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Tokyo 102-0075, Japan.
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70
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Uchihashi T, Scheuring S. Applications of high-speed atomic force microscopy to real-time visualization of dynamic biomolecular processes. Biochim Biophys Acta Gen Subj 2018; 1862:229-240. [DOI: 10.1016/j.bbagen.2017.07.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 07/13/2017] [Indexed: 12/12/2022]
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71
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Structure and dynamics of rotary V 1 motor. Cell Mol Life Sci 2018; 75:1789-1802. [PMID: 29387903 PMCID: PMC5910484 DOI: 10.1007/s00018-018-2758-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 12/25/2017] [Accepted: 01/18/2018] [Indexed: 12/14/2022]
Abstract
Rotary ATPases are unique rotary molecular motors that function as energy conversion machines. Among all known rotary ATPases, F1-ATPase is the best characterized rotary molecular motor. There are many high-resolution crystal structures and the rotation dynamics have been investigated in detail by extensive single-molecule studies. In contrast, knowledge on the structure and rotation dynamics of V1-ATPase, another rotary ATPase, has been limited. However, recent high-resolution structural studies and single-molecule studies on V1-ATPase have provided new insights on how the catalytic sites in this molecular motor change its conformation during rotation driven by ATP hydrolysis. In this review, we summarize recent information on the structural features and rotary dynamics of V1-ATPase revealed from structural and single-molecule approaches and discuss the possible chemomechanical coupling scheme of V1-ATPase with a focus on differences between rotary molecular motors.
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72
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Ivanov IE, Lebel P, Oberstrass FC, Starr CH, Parente AC, Ierokomos A, Bryant Z. Multimodal Measurements of Single-Molecule Dynamics Using FluoRBT. Biophys J 2018; 114:278-282. [PMID: 29248150 PMCID: PMC5984952 DOI: 10.1016/j.bpj.2017.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/15/2017] [Accepted: 11/08/2017] [Indexed: 11/21/2022] Open
Abstract
Single-molecule methods provide direct measurements of macromolecular dynamics, but are limited by the number of degrees of freedom that can be followed at one time. High-resolution rotor bead tracking (RBT) measures DNA torque, twist, and extension, and can be used to characterize the structural dynamics of DNA and diverse nucleoprotein complexes. Here, we extend RBT to enable simultaneous monitoring of additional degrees of freedom. Fluorescence-RBT (FluoRBT) combines magnetic tweezers, infrared evanescent scattering, and single-molecule FRET imaging, providing real-time multiparameter measurements of complex molecular processes. We demonstrate the capabilities of FluoRBT by conducting simultaneous measurements of extension and FRET during opening and closing of a DNA hairpin under tension, and by observing simultaneous changes in FRET and torque during a transition between right-handed B-form and left-handed Z-form DNA under controlled supercoiling. We discover unanticipated continuous changes in FRET with applied torque, and also show how FluoRBT can facilitate high-resolution FRET measurements of molecular states, by using a mechanical signal as an independent temporal reference for aligning and averaging noisy fluorescence data. By combining mechanical measurements of global DNA deformations with FRET measurements of local conformational changes, FluoRBT will enable multidimensional investigations of systems ranging from DNA structures to large macromolecular machines.
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Affiliation(s)
- Ivan E Ivanov
- Department of Chemical Engineering, Stanford University, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California
| | - Paul Lebel
- Department of Bioengineering, Stanford University, Stanford, California; Department of Applied Physics, Stanford University, Stanford, California
| | | | - Charles H Starr
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Angelica C Parente
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Athena Ierokomos
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Zev Bryant
- Department of Bioengineering, Stanford University, Stanford, California; Department of Structural Biology, Stanford University, Stanford, California.
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73
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Li J, He G, Hiroshi U, Liu W, Noji H, Qi C, Guo X. Direct Measurement of Single-Molecule Adenosine Triphosphatase Hydrolysis Dynamics. ACS NANO 2017; 11:12789-12795. [PMID: 29215860 DOI: 10.1021/acsnano.7b07639] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
F1-ATPase (F1) is a bidirectional molecular motor that hydrolyzes nearly all ATPs to fuel the cellular processes. Optical observation of labeled F1 rotation against the α3β3 hexamer ring revealed the sequential mechanical rotation steps corresponding to ATP binding/ADP release and ATP hydrolysis/Pi release. These substeps originate from the F1 rotation but with heavy load on the γ shaft due to fluorescent labeling and the photophysical limitation of an optical microscope, which hampers better understanding of the intrinsic kinetic behavior of ATP hydrolysis. In this work, we present a method capable of electrically monitoring ATP hydrolysis of a single label-free F1 in real time by using a high-gain silicon nanowire-based field-effect transistor circuit. We reproducibly observe the regular current signal fluctuations with two distinct levels, which are induced by the binding dwell and the catalytic dwell, respectively, in both concentration- and temperature-dependent experiments. In comparison with labeled F1, the hydrolysis rate of nonlabeled F1 used in this study is 1 order of magnitude faster (1.69 × 108 M-1 s-1 at 20 °C), and the differences between two sequential catalytic rates are clearer, demonstrating the ability of nanowire nanocircuits to directly probe the intrinsic dynamic processes of the biological activities with single-molecule/single-event sensitivity. This approach is complementary to traditional optical methods, offering endless opportunities to unravel molecular mechanisms of a variety of dynamic biosystems under realistic physiological conditions.
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Affiliation(s)
- Jie Li
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, P. R. China
| | - Gen He
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, P. R. China
| | - Ueno Hiroshi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo , Tokyo 113-8654, Japan
| | - Wenzhe Liu
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, P. R. China
| | - Hiroyuki Noji
- Department of Applied Chemistry, School of Engineering, The University of Tokyo , Tokyo 113-8654, Japan
| | - Chuanmin Qi
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University , Beijing 100875, P. R. China
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University , Beijing 100871, P. R. China
- Department of Materials Science and Engineering, College of Engineering, Peking University , Beijing 100871, P. R. China
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74
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Robinson BL, Dumas M, Ali SF, Paule MG, Gu Q, Kanungo J. Mechanistic studies on ketamine-induced mitochondrial toxicity in zebrafish embryos. Neurotoxicol Teratol 2017; 69:63-72. [PMID: 29225006 DOI: 10.1016/j.ntt.2017.12.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 12/06/2017] [Accepted: 12/06/2017] [Indexed: 12/26/2022]
Abstract
Ketamine, a phencyclidine derivative, is an antagonist of the Ca2+-permeable N-methyl-d-aspartate (NMDA)-type glutamate receptors. It is a pediatric anesthetic and has been implicated in developmental neurotoxicity. Ketamine has also been shown to deplete ATP in mammalian cells. Our previous studies showed that acetyl l-carnitine (ALCAR) prevented ketamine-induced cardiotoxicity and neurotoxicity in zebrafish embryos. Based on our finding that ALCAR's protective effect was blunted by oligomycin A, an inhibitor of ATP synthase, we further investigated the effects of ketamine and ALCAR on ATP levels, mitochondria and ATP synthase in zebrafish embryos. The results demonstrated that ketamine reduced ATP levels in the embryos but not in the presence of ALCAR. Ketamine reduced total mitochondrial protein levels and mitochondrial potential, which were prevented with ALCAR co-treatment. To determine the cause of ketamine-induced ATP deficiency, we explored the status of ATP synthase. The results showed that a subunit of ATP synthase, atp5α1, was transcriptionally down-regulated by ketamine, but not in the presence of ALCAR, although ketamine caused a significant upregulation in another ATP synthase subunit, atp5β and total ATP synthase protein levels. Most of the ATP generated by heart mitochondria are utilized for its contraction and relaxation. Ketamine-treated embryos showed abnormal heart structure, which was abolished with ALCAR co-treatment. This study offers evidence for a potential mechanism by which ketamine could cause ATP deficiency mediated by mitochondrial dysfunction.
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Affiliation(s)
- Bonnie L Robinson
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Melanie Dumas
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Syed F Ali
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Merle G Paule
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Qiang Gu
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Jyotshna Kanungo
- Division of Neurotoxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA.
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75
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Ekimoto T, Ikeguchi M. Multiscale molecular dynamics simulations of rotary motor proteins. Biophys Rev 2017; 10:605-615. [PMID: 29204882 DOI: 10.1007/s12551-017-0373-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/23/2017] [Indexed: 12/16/2022] Open
Abstract
Protein functions require specific structures frequently coupled with conformational changes. The scale of the structural dynamics of proteins spans from the atomic to the molecular level. Theoretically, all-atom molecular dynamics (MD) simulation is a powerful tool to investigate protein dynamics because the MD simulation is capable of capturing conformational changes obeying the intrinsically structural features. However, to study long-timescale dynamics, efficient sampling techniques and coarse-grained (CG) approaches coupled with all-atom MD simulations, termed multiscale MD simulations, are required to overcome the timescale limitation in all-atom MD simulations. Here, we review two examples of rotary motor proteins examined using free energy landscape (FEL) analysis and CG-MD simulations. In the FEL analysis, FEL is calculated as a function of reaction coordinates, and the long-timescale dynamics corresponding to conformational changes is described as transitions on the FEL surface. Another approach is the utilization of the CG model, in which the CG parameters are tuned using the fluctuation matching methodology with all-atom MD simulations. The long-timespan dynamics is then elucidated straightforwardly by using CG-MD simulations.
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Affiliation(s)
- Toru Ekimoto
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, 230-0045, Japan.
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76
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Dai L, Flechsig H, Yu J. Deciphering Intrinsic Inter-subunit Couplings that Lead to Sequential Hydrolysis of F 1-ATPase Ring. Biophys J 2017; 113:1440-1453. [PMID: 28978438 PMCID: PMC5627347 DOI: 10.1016/j.bpj.2017.08.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/31/2017] [Accepted: 08/04/2017] [Indexed: 11/05/2022] Open
Abstract
Rotary sequential hydrolysis of the metabolic machine F1-ATPase is a prominent manifestation of high coordination among multiple chemical sites in ring-shaped molecular machines, and it is also functionally essential for F1 to tightly couple chemical reactions and central γ-shaft rotation. High-speed AFM experiments have identified that sequential hydrolysis is maintained in the F1 stator ring even in the absence of the γ-rotor. To explore the origins of intrinsic sequential performance, we computationally investigated essential inter-subunit couplings on the hexameric ring of mitochondrial and bacterial F1. We first reproduced in stochastic Monte Carlo simulations the experimentally determined sequential hydrolysis schemes by kinetically imposing inter-subunit couplings and following subsequent tri-site ATP hydrolysis cycles on the F1 ring. We found that the key couplings to support the sequential hydrolysis are those that accelerate neighbor-site ADP and Pi release upon a certain ATP binding or hydrolysis reaction. The kinetically identified couplings were then examined in atomistic molecular dynamics simulations at a coarse-grained level to reveal the underlying structural mechanisms. To do that, we enforced targeted conformational changes of ATP binding or hydrolysis to one chemical site on the F1 ring and monitored the ensuing conformational responses of the neighboring sites using structure-based simulations. Notably, we found asymmetrical neighbor-site opening that facilitates ADP release upon enforced ATP binding. We also captured a complete charge-hopping process of the Pi release subsequent to enforced ATP hydrolysis in the neighbor site, confirming recent single-molecule analyses with regard to the role of ATP hydrolysis in F1. Our studies therefore elucidate both the coordinated chemical kinetics and structural dynamics mechanisms underpinning the sequential operation of the F1 ring.
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Affiliation(s)
- Liqiang Dai
- Complex System Research Division, Beijing Computational Science Research Center, Beijing, China
| | - Holger Flechsig
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Hiroshima, Japan
| | - Jin Yu
- Complex System Research Division, Beijing Computational Science Research Center, Beijing, China.
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77
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Yamato I, Murata T, Khrennikov A. Energy and information flows in biological systems: Bioenergy transduction of V 1 -ATPase rotary motor and dynamics of thermodynamic entropy in information flows. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:33-38. [DOI: 10.1016/j.pbiomolbio.2017.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 03/16/2017] [Accepted: 04/13/2017] [Indexed: 12/20/2022]
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78
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Yanagisawa S, Frasch WD. Protonation-dependent stepped rotation of the F-type ATP synthase c-ring observed by single-molecule measurements. J Biol Chem 2017; 292:17093-17100. [PMID: 28842481 PMCID: PMC5641864 DOI: 10.1074/jbc.m117.799940] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/02/2017] [Indexed: 11/06/2022] Open
Abstract
The two opposed rotary molecular motors of the F0F1-ATP synthase work together to provide the majority of ATP in biological organisms. Rotation occurs in 120° power strokes separated by dwells when F1 synthesizes or hydrolyzes ATP. F0 and F1 complexes connect via a central rotor stalk and a peripheral stator stalk. A major unresolved question is the mechanism in which the interaction between subunit-a and rotating subunit-c-ring in the F0 motor uses the flux of H+ across the membrane to induce clockwise rotation against the force of counterclockwise rotation driven by the F1-ATPase. In single-molecule measurements of F0F1 embedded in lipid bilayer nanodiscs, we observed that the ability of the F0 motor to form transient dwells increases with decreasing pH. Transient dwells can halt counterclockwise rotation powered by the F1-ATPase in steps equivalent to the rotation of single c-subunits in the c-ring of F0, and can push the common axle shared by the two motors clockwise by as much as one c-subunit. Because the F0 proton half-channels that access the periplasm and the cytoplasm are exposed to the same pH, these data are consistent with the conclusion that the periplasmic half-channel is more easily protonated in a manner that halts ATPase-driven rotation by blocking ATPase-dependent proton pumping. The fit of transient dwell occurrence to the sum of three Gaussian curves suggests that the asymmetry of the three ATPase-dependent 120° power strokes imposed by the relative positions of the central and peripheral stalks affects c-subunit stepping efficiency.
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Affiliation(s)
- Seiga Yanagisawa
- From the School of Life Sciences, Arizona State University, Tempe, Arizona, 85287-4501
| | - Wayne D Frasch
- From the School of Life Sciences, Arizona State University, Tempe, Arizona, 85287-4501
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79
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Mukherjee S, Warshel A. The F OF 1 ATP synthase: from atomistic three-dimensional structure to the rotary-chemical function. PHOTOSYNTHESIS RESEARCH 2017; 134:1-15. [PMID: 28674936 PMCID: PMC5693661 DOI: 10.1007/s11120-017-0411-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 05/25/2017] [Indexed: 05/29/2023]
Abstract
Molecular motors are multi-subunit complexes that are indispensable for accomplishing various tasks of the living cells. One such molecular motor is the FOF1 ATP synthase that synthesizes ATP at the expense of the membrane proton gradient. Elucidating the molecular origin of the motor function is challenging despite significant advances in various experimental fields. Currently atomic simulations of whole motor complexes cannot reach to functionally relevant time scales that extend beyond the millisecond regime. Moreover, to reveal the underlying molecular origin of the function, one must model the coupled chemical and conformational events using physically and chemically meaningful multiscaling techniques. In this review, we discuss our approach to model the action of the F1 and FO molecular motors, where emphasis is laid on elucidating the molecular origin of the driving force that leads to directional rotation at the expense of ATP hydrolysis or proton gradients. We have used atomic structures of the motors and used hierarchical multiscaling techniques to generate low dimensional functional free energy surfaces of the complete mechano-chemical process. These free energy surfaces were studied further to calculate important characteristics of the motors, such as, rotational torque, temporal dynamics, occurrence of intermittent dwell states, etc. We also studied the result of mutating various parts of the motor domains and our observations correspond very well with the experimental findings. Overall, our studies have generated a cumulative understanding of the motor action, and especially highlight the crucial role of electrostatics in establishing the mechano-chemical coupling.
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Affiliation(s)
- Shayantani Mukherjee
- Department of Chemistry, University of Southern California, 3620 McClintock Avenue, Los Angeles, CA, 90089, USA.
| | - Arieh Warshel
- Department of Chemistry, University of Southern California, 3620 McClintock Avenue, Los Angeles, CA, 90089, USA.
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80
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Iino R, Iida T, Nakamura A, Saita EI, You H, Sako Y. Single-molecule imaging and manipulation of biomolecular machines and systems. Biochim Biophys Acta Gen Subj 2017; 1862:241-252. [PMID: 28789884 DOI: 10.1016/j.bbagen.2017.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/23/2017] [Accepted: 08/03/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Biological molecular machines support various activities and behaviors of cells, such as energy production, signal transduction, growth, differentiation, and migration. SCOPE OF REVIEW We provide an overview of single-molecule imaging methods involving both small and large probes used to monitor the dynamic motions of molecular machines in vitro (purified proteins) and in living cells, and single-molecule manipulation methods used to measure the forces, mechanical properties and responses of biomolecules. We also introduce several examples of single-molecule analysis, focusing primarily on motor proteins and signal transduction systems. MAJOR CONCLUSIONS Single-molecule analysis is a powerful approach to unveil the operational mechanisms both of individual molecular machines and of systems consisting of many molecular machines. GENERAL SIGNIFICANCE Quantitative, high-resolution single-molecule analyses of biomolecular systems at the various hierarchies of life will help to answer our fundamental question: "What is life?" This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato.
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Affiliation(s)
- Ryota Iino
- Okazaki Institute for Integrative Bioscience, Institute for Molecular Science, National Institutes of Natural Sciences, Japan; Department of Functional Molecular Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Japan.
| | - Tatsuya Iida
- Okazaki Institute for Integrative Bioscience, Institute for Molecular Science, National Institutes of Natural Sciences, Japan; Department of Functional Molecular Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Japan
| | - Akihiko Nakamura
- Okazaki Institute for Integrative Bioscience, Institute for Molecular Science, National Institutes of Natural Sciences, Japan; Department of Functional Molecular Science, School of Physical Sciences, The Graduate University for Advanced Studies (SOKENDAI), Japan
| | - Ei-Ichiro Saita
- Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, Japan
| | - Huijuan You
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, China.
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81
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Isaka Y, Ekimoto T, Kokabu Y, Yamato I, Murata T, Ikeguchi M. Rotation Mechanism of Molecular Motor V 1-ATPase Studied by Multiscale Molecular Dynamics Simulation. Biophys J 2017; 112:911-920. [PMID: 28297650 PMCID: PMC5355535 DOI: 10.1016/j.bpj.2017.01.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 01/06/2017] [Accepted: 01/30/2017] [Indexed: 11/28/2022] Open
Abstract
Enterococcus hirae V1-ATPase is a molecular motor composed of the A3B3 hexamer ring and the central stalk. In association with ATP hydrolysis, three catalytic AB pairs in the A3B3 ring undergo conformational changes, which lead to a 120° rotation of the central stalk. To understand how the conformational changes of three catalytic pairs induce the 120° rotation of the central stalk, we performed multiscale molecular dynamics (MD) simulations in which coarse-grained and all-atom MD simulations were combined using a fluctuation matching methodology. During the rotation, a catalytic AB pair spontaneously adopted an intermediate conformation, which was not included in the initial inputs of the simulations and was essentially close to the “bindable-like” structure observed in a recently solved crystal structure. Furthermore, the creation of a space between the bindable-like and tight pairs was required for the central stalk to rotate without steric hindrance. These cooperative rearrangements of the three catalytic pairs are crucial for the rotation of the central stalk.
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Affiliation(s)
- Yuta Isaka
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Toru Ekimoto
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Yuichi Kokabu
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan
| | - Ichiro Yamato
- Department of Biological Science and Technology, Tokyo University of Science, Katsushika-ku, Tokyo, Japan
| | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba, Japan; JST, PRESTO, Inage, Chiba, Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi, Yokohama, Japan.
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82
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Ragunathan P, Sielaff H, Sundararaman L, Biuković G, Subramanian Manimekalai MS, Singh D, Kundu S, Wohland T, Frasch W, Dick T, Grüber G. The uniqueness of subunit α of mycobacterial F-ATP synthases: An evolutionary variant for niche adaptation. J Biol Chem 2017; 292:11262-11279. [PMID: 28495884 PMCID: PMC5500794 DOI: 10.1074/jbc.m117.784959] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/11/2017] [Indexed: 01/30/2023] Open
Abstract
The F1F0 -ATP (F-ATP) synthase is essential for growth of Mycobacterium tuberculosis, the causative agent of tuberculosis (TB). In addition to their synthase function most F-ATP synthases possess an ATP-hydrolase activity, which is coupled to proton-pumping activity. However, the mycobacterial enzyme lacks this reverse activity, but the reason for this deficiency is unclear. Here, we report that a Mycobacterium-specific, 36-amino acid long C-terminal domain in the nucleotide-binding subunit α (Mtα) of F-ATP synthase suppresses its ATPase activity and determined the mechanism of suppression. First, we employed vesicles to show that in intact membrane-embedded mycobacterial F-ATP synthases deletion of the C-terminal domain enabled ATPase and proton-pumping activity. We then generated a heterologous F-ATP synthase model system, which demonstrated that transfer of the mycobacterial C-terminal domain to a standard F-ATP synthase α subunit suppresses ATPase activity. Single-molecule rotation assays indicated that the introduction of this Mycobacterium-specific domain decreased the angular velocity of the power-stroke after ATP binding. Solution X-ray scattering data and NMR results revealed the solution shape of Mtα and the 3D structure of the subunit α C-terminal peptide 521PDEHVEALDEDKLAKEAVKV540 of M. tubercolosis (Mtα(521-540)), respectively. Together with cross-linking studies, the solution structural data lead to a model, in which Mtα(521-540) comes in close proximity with subunit γ residues 104-109, whose interaction may influence the rotation of the camshaft-like subunit γ. Finally, we propose that the unique segment Mtα(514-549), which is accessible at the C terminus of mycobacterial subunit α, is a promising drug epitope.
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Affiliation(s)
- Priya Ragunathan
- From the Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Hendrik Sielaff
- From the Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Lavanya Sundararaman
- From the Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Goran Biuković
- the Department of Microbiology and Immunology, National University of Singapore, Yong Loo Lin School of Medicine, 14 Medical Drive, Singapore 117599, Republic of Singapore
| | | | - Dhirendra Singh
- From the Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Subhashri Kundu
- the Department of Microbiology and Immunology, National University of Singapore, Yong Loo Lin School of Medicine, 14 Medical Drive, Singapore 117599, Republic of Singapore
| | - Thorsten Wohland
- the Departments of Biological Sciences and Chemistry and NUS Centre for Bioimaging Sciences (CBIS), National University of Singapore, 14 Science Drive 4, Singapore 117557, Republic of Singapore, and
| | - Wayne Frasch
- School of Life Sciences, Arizona State University, Tempe, Arizona 85287
| | - Thomas Dick
- the Department of Microbiology and Immunology, National University of Singapore, Yong Loo Lin School of Medicine, 14 Medical Drive, Singapore 117599, Republic of Singapore
| | - Gerhard Grüber
- From the Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore,
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83
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Theory of long binding events in single-molecule-controlled rotation experiments on F 1-ATPase. Proc Natl Acad Sci U S A 2017; 114:7272-7277. [PMID: 28652332 DOI: 10.1073/pnas.1705960114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The theory of elastic group transfer for the binding and release rate constants for nucleotides in F1-ATPase as a function of the rotor angle is further extended in several respects. (i) A method is described for predicting the experimentally observed lifetime distribution of long binding events in the controlled rotation experiments by taking into account the hydrolysis and synthesis reactions occurring during these events. (ii) A method is also given for treating the long binding events in the experiments and obtaining the rate constants for the hydrolysis and synthesis reactions occurring during these events. (iii) The theory in the previous paper is given in a symmetric form, an extension that simplifies the application of the theory to experiments. It also includes a theory-based correction of the reported "on" and "off" rates by calculating the missed events. A near symmetry of the data about the angle of -40° and a "turnover" in the binding rate data vs. rotor angle for angles greater than [Formula: see text]40° is also discussed.
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84
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Ai G, Liu P, Ge H. Torque-coupled thermodynamic model for F_{o}F_{1}-ATPase. Phys Rev E 2017; 95:052413. [PMID: 28618520 DOI: 10.1103/physreve.95.052413] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Indexed: 01/23/2023]
Abstract
F_{o}F_{1}-ATPase is a motor protein complex that utilizes transmembrane ion flow to drive the synthesis of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate (Pi). While many theoretical models have been proposed to account for its rotary activity, most of them focus on the F_{o} or F_{1} portions separately rather than the complex as a whole. Here, we propose a simple but new torque-coupled thermodynamic model of F_{o}F_{1}-ATPase. Solving this model at steady state, we find that the monotonic variation of each portion's efficiency becomes much more robust over a wide range of parameters when the F_{o} and F_{1} portions are coupled together, as compared to cases when they are considered separately. Furthermore, the coupled model predicts the dependence of each portion's kinetic behavior on the parameters of the other. Specifically, the power and efficiency of the F_{1} portion are quite sensitive to the proton gradient across the membrane, while those of the F_{o} portion as well as the related Michaelis constants for proton concentrations respond insensitively to concentration changes in the reactants of ATP synthesis. The physiological proton gradient across the membrane in the F_{o} portion is also shown to be optimal for the Michaelis constants of ADP and phosphate in the F_{1} portion during ATP synthesis. Together, our coupled model is able to predict key dynamic and thermodynamic features of the F_{o}F_{1}-ATPase in vivo semiquantitatively, and suggests that such coupling approach could be further applied to other biophysical systems.
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Affiliation(s)
- Guangkuo Ai
- Beijing International Center for Mathematical Research and School of Mathematical Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Pengfei Liu
- Applied and Computational Mathematics, California Institute of Technology, Pasadena, California 91125, USA
| | - Hao Ge
- Beijing International Center for Mathematical Research and Biodynamic Optical Imaging Center, Peking University, Beijing 100871, People's Republic of China
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85
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Minges A, Ciupka D, Winkler C, Höppner A, Gohlke H, Groth G. Structural intermediates and directionality of the swiveling motion of Pyruvate Phosphate Dikinase. Sci Rep 2017; 7:45389. [PMID: 28358005 PMCID: PMC5371819 DOI: 10.1038/srep45389] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/23/2017] [Indexed: 12/13/2022] Open
Abstract
Pyruvate phosphate dikinase (PPDK) is a vital enzyme in cellular energy metabolism catalyzing the ATP- and Pi-dependent formation of phosphoenolpyruvate from pyruvate in C4 -plants, but the reverse reaction forming ATP in bacteria and protozoa. The multi-domain enzyme is considered an efficient molecular machine that performs one of the largest single domain movements in proteins. However, a comprehensive understanding of the proposed swiveling domain motion has been limited by not knowing structural intermediates or molecular dynamics of the catalytic process. Here, we present crystal structures of PPDKs from Flaveria, a model genus for studying the evolution of C4 -enzymes from phylogenetic ancestors. These structures resolve yet unknown conformational intermediates and provide the first detailed view on the large conformational transitions of the protein in the catalytic cycle. Independently performed unrestrained MD simulations and configurational free energy calculations also identified these intermediates. In all, our experimental and computational data reveal strict coupling of the CD swiveling motion to the conformational state of the NBD. Moreover, structural asymmetries and nucleotide binding states in the PPDK dimer support an alternate binding change mechanism for this intriguing bioenergetic enzyme.
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Affiliation(s)
- Alexander Minges
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
| | - Daniel Ciupka
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
| | - Christian Winkler
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
| | - Astrid Höppner
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
| | - Holger Gohlke
- Institute of Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
| | - Georg Groth
- Cluster of Excellence on Plant Sciences (CEPLAS), Institute of Biochemical Plant Physiology, Heinrich Heine University Düsseldorf, 40204 Düsseldorf, Germany
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86
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Noji H, Ueno H, McMillan DGG. Catalytic robustness and torque generation of the F 1-ATPase. Biophys Rev 2017; 9:103-118. [PMID: 28424741 PMCID: PMC5380711 DOI: 10.1007/s12551-017-0262-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/13/2017] [Indexed: 12/28/2022] Open
Abstract
The F1-ATPase is the catalytic portion of the FoF1 ATP synthase and acts as a rotary molecular motor when it hydrolyzes ATP. Two decades have passed since the single-molecule rotation assay of F1-ATPase was established. Although several fundamental issues remain elusive, basic properties of F-type ATPases as motor proteins have been well characterized, and a large part of the reaction scheme has been revealed by the combination of extensive structural, biochemical, biophysical, and theoretical studies. This review is intended to provide a concise summary of the fundamental features of F1-ATPases, by use of the well-described model F1 from the thermophilic Bacillus PS3 (TF1). In the last part of this review, we focus on the robustness of the rotary catalysis of F1-ATPase to provide a perspective on the re-designing of novel molecular machines.
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Affiliation(s)
- Hiroyuki Noji
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo, 113-8656 Japan
| | - Hiroshi Ueno
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo, 113-8656 Japan
| | - Duncan G. G. McMillan
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo, 113-8656 Japan
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87
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Anandakrishnan R, Zuckerman DM. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio. PLoS One 2017; 12:e0173500. [PMID: 28319179 PMCID: PMC5358804 DOI: 10.1371/journal.pone.0173500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/21/2017] [Indexed: 12/15/2022] Open
Abstract
ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access and other possible mechanisms suggest that, when the ratio of protons transported per ATP hydrolyzed exceeds one, the one-at-a-time proton transport by the rotary mechanism is faster than other possible mechanisms across a wide range of driving conditions. When the ratio is one, there is no intrinsic difference in the free energy landscape between mechanisms, and therefore all mechanisms can exhibit the same kinetic performance. To our knowledge all known rotary pumps have an H+:ATP ratio greater than one, and all known alternating access ATP-driven proton pumps have a ratio of one. Our analysis suggests a possible explanation for this apparent relationship between coupling ratio and mechanism. When the conditions under which the pump must operate permit a coupling ratio greater than one, the rotary mechanism may have been selected for its kinetic advantage. On the other hand, when conditions require a coupling ratio of one or less, the alternating access mechanism may have been selected for other possible advantages resulting from its structural and functional simplicity.
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Affiliation(s)
- Ramu Anandakrishnan
- Dept. of Computational and Systems Biology, School of Medicine, University of Pittsburgh, PA, United States of America
- * E-mail: (RA); (DMZ)
| | - Daniel M. Zuckerman
- Dept. of Computational and Systems Biology, School of Medicine, University of Pittsburgh, PA, United States of America
- * E-mail: (RA); (DMZ)
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88
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Oot RA, Couoh-Cardel S, Sharma S, Stam NJ, Wilkens S. Breaking up and making up: The secret life of the vacuolar H + -ATPase. Protein Sci 2017; 26:896-909. [PMID: 28247968 DOI: 10.1002/pro.3147] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 02/21/2017] [Indexed: 01/24/2023]
Abstract
The vacuolar ATPase (V-ATPase; V1 Vo -ATPase) is a large multisubunit proton pump found in the endomembrane system of all eukaryotic cells where it acidifies the lumen of subcellular organelles including lysosomes, endosomes, the Golgi apparatus, and clathrin-coated vesicles. V-ATPase function is essential for pH and ion homeostasis, protein trafficking, endocytosis, mechanistic target of rapamycin (mTOR), and Notch signaling, as well as hormone secretion and neurotransmitter release. V-ATPase can also be found in the plasma membrane of polarized animal cells where its proton pumping function is involved in bone remodeling, urine acidification, and sperm maturation. Aberrant (hypo or hyper) activity has been associated with numerous human diseases and the V-ATPase has therefore been recognized as a potential drug target. Recent progress with moderate to high-resolution structure determination by cryo electron microscopy and X-ray crystallography together with sophisticated single-molecule and biochemical experiments have provided a detailed picture of the structure and unique mode of regulation of the V-ATPase. This review summarizes the recent advances, focusing on the structural and biophysical aspects of the field.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Sergio Couoh-Cardel
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Stuti Sharma
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Nicholas J Stam
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
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89
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Czub J, Wieczór M, Prokopowicz B, Grubmüller H. Mechanochemical Energy Transduction during the Main Rotary Step in the Synthesis Cycle of F 1-ATPase. J Am Chem Soc 2017; 139:4025-4034. [PMID: 28253614 DOI: 10.1021/jacs.6b11708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
F1-ATPase is a highly efficient molecular motor that can synthesize ATP driven by a mechanical torque. Its ability to function reversibly in either direction requires tight mechanochemical coupling between the catalytic domain and the rotating central shaft, as well as temporal control of substrate binding and product release. Despite great efforts and significant progress, the molecular details of this synchronized and fine-tuned energy conversion mechanism are not fully understood. Here, we use extensive molecular dynamics simulations to reconcile recent single-molecule experiments with structural data and provide a consistent thermodynamic, kinetic and mechanistic description of the main rotary substep in the synthetic cycle of mammalian ATP synthase. The calculated free energy profiles capture a discrete pattern in the rotation of the central γ-shaft, with a metastable intermediate located-consistently with recent experimental findings-at 70° relative to the X-ray position. We identify this rotary step as the ATP-dependent substep, and find that the associated free energy input supports the mechanism involving concurrent nucleotide binding and release. During the main substep, our simulations show no significant opening of the ATP-bound β subunit; instead, we observe that mechanical energy is transmitted to its nucleotide binding site, thus lowering the affinity for ATP. Simultaneously, the empty subunit assumes a conformation that enables the enzyme to harness the free energy of ADP binding to drive ATP release. Finally, we show that ligand exchange is regulated by a checkpoint mechanism, an apparent prerequisite for high efficiency in protein nanomotors.
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Affiliation(s)
- Jacek Czub
- Department of Physical Chemistry, Gdansk University of Technology , ul. Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Miłosz Wieczór
- Department of Physical Chemistry, Gdansk University of Technology , ul. Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Bartosz Prokopowicz
- Department of Physical Chemistry, Gdansk University of Technology , ul. Narutowicza 11/12, 80-233 Gdańsk, Poland
| | - Helmut Grubmüller
- Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry , Am Fassberg 11, 37077 Göttingen, Germany
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90
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Fujimura S, Ito Y, Ikeguchi M, Adachi K, Yajima J, Nishizaka T. Dissection of the angle of single fluorophore attached to the nucleotide in corkscrewing microtubules. Biochem Biophys Res Commun 2017; 485:614-620. [PMID: 28257843 DOI: 10.1016/j.bbrc.2017.01.165] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 01/28/2017] [Indexed: 11/18/2022]
Abstract
Direct dissection of the angles of single fluorophores under an optical microscope has been a challenging approach to study the dynamics of proteins in an aqueous solution. For angle quantifications of single substrates, however, there was only one report (Nishizaka et al., 2014) because of difficulties of construction of experimental systems with active proteins working at the single-molecule level. We here show precise estimation of orientation of single fluorescent nucleotides bound to single tubulins that comprise microtubule. When single-headed kinesins immobilized on a glass surface drive the sliding of microtubules, microtubules show corkscrewing with regular pitches (Yajima et al., 2005 & 2008). We found, by using a three-dimensional tracking microscope, that S8A mutant kinesin also showed precise corkscrewing with a 330-nm pitch, which is 13% longer than that of the wild type. The assay with the mutant was combined with a defocused imaging technique to visualize the rotational behavior of fluorescent nucleotide bound to corkscrewing microtubule. Notably, the defocused pattern of single TAMRA-GTP periodically changed, precisely correlating to its precession movement. The time course of the change in the fluorophore angle projected to the xy-plane enabled to estimate both the fluorophore orientation against microtubule axis and the precision of angle-determination of analyses system. The orientation showed main distribution with peaks at∼40°, 50° and 60°. To identify their molecular conformations, the rigorous docking simulations were performed using an atomic-level structure modeled by fitting x-ray crystal structures to the cryo-electron microscopy map. Among isomers, 2'-O-EDA-GDP labeled with 5- or 6-TAMRA were mainly specified as possible candidates as a substrate, which suggested the hydrolysis of TAMRA-GTP by tubulins.
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Affiliation(s)
- Shoko Fujimura
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan
| | - Yuko Ito
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Kengo Adachi
- Department of Physics, Faculty of Science and Engineering, Waseda University, Tokyo 169-8555, Japan
| | - Junichiro Yajima
- Department of Life Sciences, Graduate School of Arts & Sciences, The University of Tokyo, Tokyo 153-8902, Japan
| | - Takayuki Nishizaka
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo 171-8588, Japan.
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91
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Singharoy A, Chipot C, Moradi M, Schulten K. Chemomechanical Coupling in Hexameric Protein-Protein Interfaces Harnesses Energy within V-Type ATPases. J Am Chem Soc 2017; 139:293-310. [PMID: 27936329 PMCID: PMC5518570 DOI: 10.1021/jacs.6b10744] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
ATP synthase is the most prominent bioenergetic macromolecular motor in all life forms, utilizing the proton gradient across the cell membrane to fuel the synthesis of ATP. Notwithstanding the wealth of available biochemical and structural information inferred from years of experiments, the precise molecular mechanism whereby vacuolar (V-type) ATP synthase fulfills its biological function remains largely fragmentary. Recently, crystallographers provided the first high-resolution view of ATP activity in Enterococcus hirae V1-ATPase. Employing a combination of transition-path sampling and high-performance free-energy methods, the sequence of conformational transitions involved in a functional cycle accompanying ATP hydrolysis has been investigated in unprecedented detail over an aggregate simulation time of 65 μs. Our simulated pathways reveal that the chemical energy produced by ATP hydrolysis is harnessed via the concerted motion of the protein-protein interfaces in the V1-ring, and is nearly entirely consumed in the rotation of the central stalk. Surprisingly, in an ATPase devoid of a central stalk, the interfaces of this ring are perfectly designed for inducing ATP hydrolysis. However, in a complete V1-ATPase, the mechanical property of the central stalk is a key determinant of the rate of ATP turnover. The simulations further unveil a sequence of events, whereby unbinding of the hydrolysis product (ADP + Pi) is followed by ATP uptake, which, in turn, leads to the torque generation step and rotation of the center stalk. Molecular trajectories also bring to light multiple intermediates, two of which have been isolated in independent crystallography experiments.
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Affiliation(s)
- Abhishek Singharoy
- Theoretical and Computational Biophysics Group, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Christophe Chipot
- Theoretical and Computational Biophysics Group, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , 405 North Mathews Avenue, Urbana, Illinois 61801, United States
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Unité Mixte de Recherche n°7565, Université de Lorraine , B.P. 70239, 54506 Vandœuvre-lès-Nancy Cedex, France
- Department of Physics, University of Illinois at Urbana-Champaign , 1110 West Green Street, Urbana, Illinois 61801, United States
| | - Mahmoud Moradi
- Department of Chemistry and Biochemistry, University of Arkansas , Fayetteville, Arkansas 72701, United States
| | - Klaus Schulten
- Theoretical and Computational Biophysics Group, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign , 405 North Mathews Avenue, Urbana, Illinois 61801, United States
- Department of Physics, University of Illinois at Urbana-Champaign , 1110 West Green Street, Urbana, Illinois 61801, United States
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92
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AKUTSU H. Dynamic mechanisms driving conformational conversions of the β and ε subunits involved in rotational catalysis of F 1-ATPase. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:630-647. [PMID: 29021512 PMCID: PMC5743862 DOI: 10.2183/pjab.93.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/16/2017] [Indexed: 05/26/2023]
Abstract
F-type ATPase is a ubiquitous molecular motor. Investigations on thermophilic F1-ATPase and its subunits, β and ε, by NMR were reviewed. Using specific isotope labeling, pKa of the putative catalytic carboxylate in β was estimated. Segmental isotope-labeling enabled us to monitor most residues of β, revealing that the conformational conversion from open to closed form of β on nucleotide binding found in ATPase was an intrinsic property of β and could work as a driving force of the rotational catalysis. A stepwise conformational change was driven by switching of the hydrogen bond networks involving Walker A and B motifs. Segmentally labeled ATPase provided a well resolved NMR spectra, revealing while the open form of β was identical for β monomer and ATPase, its closed form could be different. ATP-binding was also a critical factor in the conformational conversion of ε, an ATP hydrolysis inhibitor. Its structural elucidation was described.
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Affiliation(s)
- Hideo AKUTSU
- Institute for Protein Research, Osaka University, Osaka, Japan
- Graduate School of Medical Life Science, Yokohama City University, Yokohama, Japan
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93
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Suzuki K, Mizutani K, Maruyama S, Shimono K, Imai FL, Muneyuki E, Kakinuma Y, Ishizuka-Katsura Y, Shirouzu M, Yokoyama S, Yamato I, Murata T. Crystal structures of the ATP-binding and ADP-release dwells of the V 1 rotary motor. Nat Commun 2016; 7:13235. [PMID: 27807367 PMCID: PMC5095293 DOI: 10.1038/ncomms13235] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 09/14/2016] [Indexed: 12/21/2022] Open
Abstract
V1-ATPases are highly conserved ATP-driven rotary molecular motors found in various membrane systems. We recently reported the crystal structures for the Enterococcus hirae A3B3DF (V1) complex, corresponding to the catalytic dwell state waiting for ATP hydrolysis. Here we present the crystal structures for two other dwell states obtained by soaking nucleotide-free V1 crystals in ADP. In the presence of 20 μM ADP, two ADP molecules bind to two of three binding sites and cooperatively induce conformational changes of the third site to an ATP-binding mode, corresponding to the ATP-binding dwell. In the presence of 2 mM ADP, all nucleotide-binding sites are occupied by ADP to induce conformational changes corresponding to the ADP-release dwell. Based on these and previous findings, we propose a V1-ATPase rotational mechanism model.
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Affiliation(s)
- Kano Suzuki
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Kenji Mizutani
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Shintaro Maruyama
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Kazumi Shimono
- Faculty of Pharmaceutical Sciences, Toho University, 2-2-1 Miyama, Funabashi 274-8510, Japan
| | - Fabiana L. Imai
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Eiro Muneyuki
- Department of Physics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Tokyo 112-8551, Japan
| | - Yoshimi Kakinuma
- Laboratory of Molecular Physiology and Genetics, Faculty of Agriculture, Ehime University, 3-5-7 Tarumi, Matsuyama, Ehime 790-8566, Japan
| | - Yoshiko Ishizuka-Katsura
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
| | - Mikako Shirouzu
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
| | - Shigeyuki Yokoyama
- RIKEN Structural Biology Laboratory, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
| | - Ichiro Yamato
- Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
| | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, 1-7-22 Suehiro-cho, Tsurumi, Yokohama 230-0045, Japan
- JST, PRESTO, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
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94
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Suzuki T, Iida N, Suzuki J, Watanabe Y, Endo T, Hisabori T, Yoshida M. Expression of mammalian mitochondrial F 1-ATPase in Escherichia coli depends on two chaperone factors, AF1 and AF2. FEBS Open Bio 2016; 6:1267-1272. [PMID: 28203526 PMCID: PMC5302055 DOI: 10.1002/2211-5463.12143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 10/05/2016] [Accepted: 10/06/2016] [Indexed: 11/06/2022] Open
Abstract
F1‐ATPase (F1) is a multisubunit water‐soluble domain of FoF1‐ATP synthase and is a rotary enzyme by itself. Earlier genetic studies using yeast suggested that two factors, Atp11p and Atp12p, contribute to F1 assembly. Here, we show that their mammalian counterparts, AF1 and AF2, are essential and sufficient for efficient production of recombinant bovine mitochondrial F1 in Escherichia coli cells. Intactness of the function and conformation of the E. coli‐expressed bovine F1 was verified by rotation analysis and crystallization. This expression system opens a way for the previously unattempted mutation study of mammalian mitochondrial F1.
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Affiliation(s)
- Toshiharu Suzuki
- Faculty of Science and Engineering Waseda University Tokyo Japan; Department of Molecular Bioscience Kyoto-Sangyo University Kyoto Japan; Chemical Resources Laboratory Tokyo Institute of Technology Yokohama Japan; Present address: Department of Applied Chemistry School of Engineering The University of Tokyo Hongo, Bunkyo-ku Tokyo 113-8656 Japan
| | - Naoya Iida
- Faculty of Science and Engineering Waseda University Tokyo Japan
| | - Junko Suzuki
- Department of Molecular Bioscience Kyoto-Sangyo University Kyoto Japan
| | - Yasunori Watanabe
- Department of Molecular Bioscience Kyoto-Sangyo University Kyoto Japan
| | - Toshiya Endo
- Department of Molecular Bioscience Kyoto-Sangyo University Kyoto Japan
| | - Toru Hisabori
- Chemical Resources Laboratory Tokyo Institute of Technology Yokohama Japan
| | - Masasuke Yoshida
- Department of Molecular Bioscience Kyoto-Sangyo University Kyoto Japan
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95
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Sielaff H, Martin J, Singh D, Biuković G, Grüber G, Frasch WD. Power Stroke Angular Velocity Profiles of Archaeal A-ATP Synthase Versus Thermophilic and Mesophilic F-ATP Synthase Molecular Motors. J Biol Chem 2016; 291:25351-25363. [PMID: 27729450 PMCID: PMC5207238 DOI: 10.1074/jbc.m116.745240] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 10/03/2016] [Indexed: 01/21/2023] Open
Abstract
The angular velocities of ATPase-dependent power strokes as a function of the rotational position for the A-type molecular motor A3B3DF, from the Methanosarcina mazei Gö1 A-ATP synthase, and the thermophilic motor α3β3γ, from Geobacillus stearothermophilus (formerly known as Bacillus PS3) F-ATP synthase, are resolved at 5 μs resolution for the first time. Unexpectedly, the angular velocity profile of the A-type was closely similar in the angular positions of accelerations and decelerations to the profiles of the evolutionarily distant F-type motors of thermophilic and mesophilic origins, and they differ only in the magnitude of their velocities. M. mazei A3B3DF power strokes occurred in 120° steps at saturating ATP concentrations like the F-type motors. However, because ATP-binding dwells did not interrupt the 120° steps at limiting ATP, ATP binding to A3B3DF must occur during the catalytic dwell. Elevated concentrations of ADP did not increase dwells occurring 40° after the catalytic dwell. In F-type motors, elevated ADP induces dwells 40° after the catalytic dwell and slows the overall velocity. The similarities in these power stroke profiles are consistent with a common rotational mechanism for A-type and F-type rotary motors, in which the angular velocity is limited by the rotary position at which ATP binding occurs and by the drag imposed on the axle as it rotates within the ring of stator subunits.
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Affiliation(s)
- Hendrik Sielaff
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, Republic of Singapore
| | - James Martin
- From the School of Life Sciences, Arizona State University, Tempe, Arizona 85287 and
| | - Dhirendra Singh
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, Republic of Singapore
| | - Goran Biuković
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, Republic of Singapore
| | - Gerhard Grüber
- the School of Biological Sciences, Nanyang Technological University, Singapore 637551, Republic of Singapore
| | - Wayne D Frasch
- From the School of Life Sciences, Arizona State University, Tempe, Arizona 85287 and
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96
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Theory of single-molecule controlled rotation experiments, predictions, tests, and comparison with stalling experiments in F1-ATPase. Proc Natl Acad Sci U S A 2016; 113:12029-12034. [PMID: 27790985 DOI: 10.1073/pnas.1611601113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
A recently proposed chemomechanical group transfer theory of rotary biomolecular motors is applied to treat single-molecule controlled rotation experiments. In these experiments, single-molecule fluorescence is used to measure the binding and release rate constants of nucleotides by monitoring the occupancy of binding sites. It is shown how missed events of nucleotide binding and release in these experiments can be corrected using theory, with F1-ATP synthase as an example. The missed events are significant when the reverse rate is very fast. Using the theory the actual rate constants in the controlled rotation experiments and the corrections are predicted from independent data, including other single-molecule rotation and ensemble biochemical experiments. The effective torsional elastic constant is found to depend on the binding/releasing nucleotide, and it is smaller for ADP than for ATP. There is a good agreement, with no adjustable parameters, between the theoretical and experimental results of controlled rotation experiments and stalling experiments, for the range of angles where the data overlap. This agreement is perhaps all the more surprising because it occurs even though the binding and release of fluorescent nucleotides is monitored at single-site occupancy concentrations, whereas the stalling and free rotation experiments have multiple-site occupancy.
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97
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Delgado-Camprubi M, Esteras N, Soutar MP, Plun-Favreau H, Abramov AY. Deficiency of Parkinson's disease-related gene Fbxo7 is associated with impaired mitochondrial metabolism by PARP activation. Cell Death Differ 2016; 24:120-131. [PMID: 27689878 PMCID: PMC5260490 DOI: 10.1038/cdd.2016.104] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 07/28/2016] [Accepted: 08/31/2016] [Indexed: 12/20/2022] Open
Abstract
The Parkinson's disease (PD)-related protein F-box only protein 7 (Fbxo7) is the substrate-recognition component of the Skp1-Cullin-F-box protein E3 ubiquitin ligase complex. We have recently shown that PD-associated mutations in Fbxo7 disrupt mitochondrial autophagy (mitophagy), suggesting a role for Fbxo7 in modulating mitochondrial homeostasis. Here we report that Fbxo7 deficiency is associated with reduced cellular NAD+ levels, which results in increased mitochondrial NADH redox index and impaired activity of complex I in the electron transport chain. Under these conditions of compromised respiration, mitochondrial membrane potential and ATP contents are reduced, and cytosolic reactive oxygen species (ROS) production is increased. ROS activates poly (ADP-ribose) polymerase (PARP) activity in Fbxo7-deficient cells. PARP inhibitor restores cellular NAD+ content and redox index and ATP pool, suggesting that PARP overactivation is cause of decreased complex I-driven respiration. These findings bring new insight into the mechanism of Fbxo7 deficiency, emphasising the importance of mitochondrial dysfunction in PD.
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Affiliation(s)
- Marta Delgado-Camprubi
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Noemi Esteras
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Marc Pm Soutar
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Helene Plun-Favreau
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
| | - Andrey Y Abramov
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square, London, UK
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98
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Substrate-translocating loops regulate mechanochemical coupling and power production in AAA+ protease ClpXP. Nat Struct Mol Biol 2016; 23:974-981. [PMID: 27669037 DOI: 10.1038/nsmb.3298] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/25/2016] [Indexed: 11/08/2022]
Abstract
ATP-dependent proteases of the AAA+ family, including Escherichia coli ClpXP and the eukaryotic proteasome, contribute to maintenance of cellular proteostasis. ClpXP unfolds and translocates substrates into an internal degradation chamber, using cycles of alternating dwell and burst phases. The ClpX motor performs chemical transformations during the dwell and translocates the substrate in increments of 1-4 nm during the burst, but the processes occurring during these phases remain unknown. Here we characterized the complete mechanochemical cycle of ClpXP, showing that ADP release and ATP binding occur nonsequentially during the dwell, whereas ATP hydrolysis and phosphate release occur during the burst. The highly conserved translocating loops within the ClpX pore are optimized to maximize motor power generation, the coupling between chemical and mechanical tasks, and the efficiency of protein processing. Conformational resetting of these loops between consecutive bursts appears to determine ADP release from individual ATPase subunits and the overall duration of the motor's cycle.
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99
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Biophysical comparison of ATP synthesis mechanisms shows a kinetic advantage for the rotary process. Proc Natl Acad Sci U S A 2016; 113:11220-11225. [PMID: 27647911 DOI: 10.1073/pnas.1608533113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The ATP synthase (F-ATPase) is a highly complex rotary machine that synthesizes ATP, powered by a proton electrochemical gradient. Why did evolution select such an elaborate mechanism over arguably simpler alternating-access processes that can be reversed to perform ATP synthesis? We studied a systematic enumeration of alternative mechanisms, using numerical and theoretical means. When the alternative models are optimized subject to fundamental thermodynamic constraints, they fail to match the kinetic ability of the rotary mechanism over a wide range of conditions, particularly under low-energy conditions. We used a physically interpretable, closed-form solution for the steady-state rate for an arbitrary chemical cycle, which clarifies kinetic effects of complex free-energy landscapes. Our analysis also yields insights into the debated "kinetic equivalence" of ATP synthesis driven by transmembrane pH and potential difference. Overall, our study suggests that the complexity of the F-ATPase may have resulted from positive selection for its kinetic advantage.
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100
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Li J, He G, Ueno H, Jia C, Noji H, Qi C, Guo X. Direct real-time detection of single proteins using silicon nanowire-based electrical circuits. NANOSCALE 2016; 8:16172-16176. [PMID: 27714062 DOI: 10.1039/c6nr04103e] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present an efficient strategy through surface functionalization to build a single silicon nanowire field-effect transistor-based biosensor that is capable of directly detecting protein adsorption/desorption at the single-event level. The step-wise signals in real-time detection of His-tag F1-ATPases demonstrate a promising electrical biosensing approach with single-molecule sensitivity, thus opening up new opportunities for studying single-molecule biophysics in broad biological systems.
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Affiliation(s)
- Jie Li
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China. and Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
| | - Gen He
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China. and Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
| | - Hiroshi Ueno
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan.
| | - Chuancheng Jia
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China.
| | - Hiroyuki Noji
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan.
| | - Chuanmin Qi
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China.
| | - Xuefeng Guo
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China. and Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, P. R. China
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