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Krah A, Vogelaar T, de Jong SI, Claridge JK, Bond PJ, McMillan DGG. ATP binding by an F 1F o ATP synthase ε subunit is pH dependent, suggesting a diversity of ε subunit functional regulation in bacteria. Front Mol Biosci 2023; 10:1059673. [PMID: 36923639 PMCID: PMC10010621 DOI: 10.3389/fmolb.2023.1059673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/03/2023] [Indexed: 03/03/2023] Open
Abstract
It is a conjecture that the ε subunit regulates ATP hydrolytic function of the F1Fo ATP synthase in bacteria. This has been proposed by the ε subunit taking an extended conformation, with a terminal helix probing into the central architecture of the hexameric catalytic domain, preventing ATP hydrolysis. The ε subunit takes a contracted conformation when bound to ATP, thus would not interfere with catalysis. A recent crystallographic study has disputed this; the Caldalkalibacillus thermarum TA2.A1 F1Fo ATP synthase cannot natively hydrolyse ATP, yet studies have demonstrated that the loss of the ε subunit terminal helix results in an ATP synthase capable of ATP hydrolysis, supporting ε subunit function. Analysis of sequence and crystallographic data of the C. thermarum F1Fo ATP synthase revealed two unique histidine residues. Molecular dynamics simulations suggested that the protonation state of these residues may influence ATP binding site stability. Yet these residues lie outside the ATP/Mg2+ binding site of the ε subunit. We then probed the effect of pH on the ATP binding affinity of the ε subunit from the C. thermarum F1Fo ATP synthase at various physiologically relevant pH values. We show that binding affinity changes 5.9 fold between pH 7.0, where binding is weakest, to pH 8.5 where it is strongest. Since the C. thermarum cytoplasm is pH 8.0 when it grows optimally, this correlates to the ε subunit being down due to ATP/Mg2+ affinity, and not being involved in blocking ATP hydrolysis. Here, we have experimentally correlated that the pH of the bacterial cytoplasm is of critical importance for ε subunit ATP affinity regulated by second-shell residues thus the function of the ε subunit changes with growth conditions.
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Affiliation(s)
- Alexander Krah
- Korea Institute for Advanced Study, School of Computational Sciences, Seoul, South Korea.,Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore
| | - Timothy Vogelaar
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Sam I de Jong
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands
| | - Jolyon K Claridge
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Duncan G G McMillan
- Department of Biotechnology, Delft University of Technology, Delft, Netherlands.,School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
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2
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Krah A, Huber RG, McMillan DGG, Bond PJ. The Molecular Basis for Purine Binding Selectivity in the Bacterial ATP Synthase ϵ Subunit. Chembiochem 2020; 21:3249-3254. [PMID: 32608105 DOI: 10.1002/cbic.202000291] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 06/30/2020] [Indexed: 12/21/2022]
Abstract
The ϵ subunit of ATP synthases has been proposed to regulate ATP hydrolysis in bacteria. Prevailing evidence supports the notion that when the ATP concentration falls below a certain threshold, the ϵ subunit changes its conformation from a non-inhibitory down-state to an extended up-state that then inhibits enzymatic ATP hydrolysis by binding to the catalytic domain. It has been demonstrated that the ϵ subunit from Bacillus PS3 is selective for ATP over other nucleotides, including GTP. In this study, the purine triphosphate selectivity is rationalized by using results from MD simulations and free energy calculations for the R103A/R115A mutant of the ϵ subunit from Bacillus PS3, which binds ATP more strongly than the wild-type protein. Our results are in good agreement with experimental data, and the elucidated molecular basis for selectivity could help to guide the design of novel GTP sensors.
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Affiliation(s)
- Alexander Krah
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore.,Korea Institute for Advanced Study, School of Computational Sciences, 85 Hoegiro, Dongdaemun-gu, Seoul, 02455, Republic of Korea
| | - Roland G Huber
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore
| | - Duncan G G McMillan
- Delft University of Technology, Department of Biotechnology, Van der Maasweg 9, Delft, 2629HZ, The Netherlands
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 30 Biopolis Str. #07-01 Matrix, Singapore, 138671, Singapore.,National University of Singapore, Department of Biological Sciences, 14 Science Drive 4, Singapore, 117543, Singapore
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3
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ATP-binding affinity of the ε subunit of thermophilic F 1-ATPase under label-free conditions. Biochem Biophys Rep 2020; 21:100725. [PMID: 31938734 PMCID: PMC6953521 DOI: 10.1016/j.bbrep.2020.100725] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 11/29/2019] [Accepted: 01/03/2020] [Indexed: 12/31/2022] Open
Abstract
The ε subunits of several bacterial F1-ATPases bind ATP. ATP binding to the ε subunit has been shown to be involved in the regulation of F1-ATPase from thermophilic Bacillus sp. PS3 (TF1). We previously reported that the dissociation constant for ATP of wild-type ε subunit of TF1 at 25 °C is 4.3 μM by measuring changes in the fluorescence of the dye attached to the ε subunit (Kato, S. et al. (2007) J. Biol. Chem.282, 37618). However, we have recently noticed that this varies with the dye used. In this report, to determine the affinity for ATP under label-free conditions, we have measured the competitive displacement of 2′(3′)-O-N′-methylaniloyl-aminoadenosine-5′-triphosphate (Mant-ATP), a fluorescent analog of ATP, by ATP. The dissociation constant for ATP of wild-type ε subunit of TF1 at 25 °C was determined to be 0.29 μM, which is one order of magnitude higher affinity than previously reported values. The ε subunit of F1-ATPase from Bacillus PS3 specifically binds ATP. Fluorescent labeling of ε subunit for the measurement may affect binding affinity. ATP binding affinity under label-free conditions was determined. Affinity of ε subunit for ATP is revised.
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Akanuma G, Tagana T, Sawada M, Suzuki S, Shimada T, Tanaka K, Kawamura F, Kato-Yamada Y. C-terminal regulatory domain of the ε subunit of F o F 1 ATP synthase enhances the ATP-dependent H + pumping that is involved in the maintenance of cellular membrane potential in Bacillus subtilis. Microbiologyopen 2019; 8:e00815. [PMID: 30809948 PMCID: PMC6692558 DOI: 10.1002/mbo3.815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 01/23/2023] Open
Abstract
The ε subunit of FoF1‐ATPase/synthase (FoF1) plays a crucial role in regulating FoF1 activity. To understand the physiological significance of the ε subunit‐mediated regulation of FoF1 in Bacillus subtilis, we constructed and characterized a mutant harboring a deletion in the C‐terminal regulatory domain of the ε subunit (ε∆C). Analyses using inverted membrane vesicles revealed that the ε∆C mutation decreased ATPase activity and the ATP‐dependent H+‐pumping activity of FoF1. To enhance the effects of ε∆C mutation, this mutation was introduced into a ∆rrn8 strain harboring only two of the 10 rrn (rRNA) operons (∆rrn8 ε∆C mutant strain). Interestingly, growth of the ∆rrn8 ε∆C mutant stalled at late‐exponential phase. During the stalled growth phase, the membrane potential of the ∆rrn8 ε∆C mutant cells was significantly reduced, which led to a decrease in the cellular level of 70S ribosomes. The growth stalling was suppressed by adding glucose into the culture medium. Our findings suggest that the C‐terminal region of the ε subunit is important for alleviating the temporal reduction in the membrane potential, by enhancing the ATP‐dependent H+‐pumping activity of FoF1.
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Affiliation(s)
- Genki Akanuma
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan.,Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
| | - Tomoaki Tagana
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
| | - Maho Sawada
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
| | - Shota Suzuki
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
| | - Tomohiro Shimada
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Yokohama, Midori-ku, Japan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Science, Tokyo Institute of Technology, Yokohama, Midori-ku, Japan
| | - Fujio Kawamura
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
| | - Yasuyuki Kato-Yamada
- Department of Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan.,Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo, Japan
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5
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Jin Z, Sun L, Yang G, Pei Y. Hydrogen Sulfide Regulates Energy Production to Delay Leaf Senescence Induced by Drought Stress in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2018; 9:1722. [PMID: 30532763 PMCID: PMC6265512 DOI: 10.3389/fpls.2018.01722] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 11/06/2018] [Indexed: 05/09/2023]
Abstract
Hydrogen sulfide (H2S) is a novel gasotransmitter in both mammals and plants. H2S plays important roles in various plant developmental processes and stress responses. Leaf senescence is the last developmental stage and is a sequential degradation process that eventually leads to leaf death. A mutation of the H2S-producing enzyme-encoding gene L-cysteine desulfhydrase1 (DES1) leads to premature leaf senescence but the underlying mechanisms are not clear. In this present study, wild-type, DES1 defective mutant (des1) and over-expression (OE-DES1) Arabidopsis plants were used to investigate the underlying mechanism of H2S signaling in energy production and leaf senescence under drought stress. The des1 mutant was more sensitive to drought stress and displayed accelerated leaf senescence, while the leaves of OE-DES1 contained adequate chlorophyll levels, accompanied by significantly increased drought resistance. Under drought stress, the expression levels of ATPβ-1, -2, and -3 were significantly downregulated in des1 and significantly upregulated in OE-DES1, and ATPε showed the opposite trend. Senescence-associated gene (SAG) 12 correlated with age-dependent senescence and participated in the drought resistance of OE-DES1. SAG13, which was induced by environmental factors, responded positively to drought stress in des1 plants, while there was no significant difference in the SAG29 expression between des1 and OE-DES1. Using transmission electron microscopy, the mitochondria of des1 were severely damaged and bubbled in older leaves, while OE-DES1 had complete mitochondrial structures and a homogeneous matrix. Additionally, mitochondria isolated from OE-DES1 increased the H2S production rate, H2S content and ATPase activity level, as well as reduced swelling and lowered the ATP content in contrast with wild-type and des1 significantly. Therefore, at subcellular levels, H2S appeared to determine the ability of mitochondria to regulate energy production and protect against cellular aging, which subsequently delayed leaf senescence under drought-stress conditions in plants.
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Affiliation(s)
- Zhuping Jin
- School of Life Science, Shanxi University, Taiyuan, China
| | - Limin Sun
- School of Life Science, Shanxi University, Taiyuan, China
| | - Guangdong Yang
- School of Life Science, Shanxi University, Taiyuan, China
- Department of Chemistry and Biochemistry, Laurentian University, Sudbury, ON, Canada
| | - Yanxi Pei
- School of Life Science, Shanxi University, Taiyuan, China
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6
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Mendoza-Hoffmann F, Zarco-Zavala M, Ortega R, García-Trejo JJ. Control of rotation of the F1FO-ATP synthase nanomotor by an inhibitory α-helix from unfolded ε or intrinsically disordered ζ and IF1 proteins. J Bioenerg Biomembr 2018; 50:403-424. [DOI: 10.1007/s10863-018-9773-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 09/13/2018] [Indexed: 12/14/2022]
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7
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Krah A, Bond PJ. Single mutations in the ε subunit from thermophilic Bacillus PS3 generate a high binding affinity site for ATP. PeerJ 2018; 6:e5505. [PMID: 30202650 PMCID: PMC6129141 DOI: 10.7717/peerj.5505] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/02/2018] [Indexed: 01/23/2023] Open
Abstract
The ε subunit from ATP synthases acts as an ATP sensor in the bacterial cell to prevent ATP hydrolysis and thus the waste of ATP under conditions of low ATP concentration. However, the ATP binding affinities from various bacterial organisms differ markedly, over several orders of magnitude. For example, the ATP synthases from thermophilic Bacillus PS3 and Escherichia coli exhibit affinities of 4 µM and 22 mM, respectively. The recently reported R103A/R115A double mutant of Bacillus PS3 ATP synthase demonstrated an increased binding affinity by two orders of magnitude with respect to the wild type. Here, we used atomic-resolution molecular dynamics simulations to determine the role of the R103A and R115A single mutations. These lead us to predict that both single mutations also cause an increased ATP binding affinity. Evolutionary analysis reveals R103 and R115 substitutions in the ε subunit from other bacillic organisms, leading us to predict they likely have a higher ATP binding affinity than previously expected.
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Affiliation(s)
- Alexander Krah
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea.,Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Peter J Bond
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, Singapore.,Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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8
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Krah A, Zarco-Zavala M, McMillan DGG. Insights into the regulatory function of the ɛ subunit from bacterial F-type ATP synthases: a comparison of structural, biochemical and biophysical data. Open Biol 2018; 8:170275. [PMID: 29769322 PMCID: PMC5990651 DOI: 10.1098/rsob.170275] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/24/2018] [Indexed: 01/07/2023] Open
Abstract
ATP synthases catalyse the formation of ATP, the most common chemical energy storage unit found in living cells. These enzymes are driven by an electrochemical ion gradient, which allows the catalytic evolution of ATP by a binding change mechanism. Most ATP synthases are capable of catalysing ATP hydrolysis to varying degrees, and to prevent wasteful ATP hydrolysis, bacteria and mitochondria have regulatory mechanisms such as ADP inhibition. Additionally, ɛ subunit inhibition has also been described in three bacterial systems, Escherichia coli, Bacillus PS3 and Caldalkalibacillus thermarum TA2.A1. Previous studies suggest that the ɛ subunit is capable of undergoing an ATP-dependent conformational change from the ATP hydrolytic inhibitory 'extended' conformation to the ATP-induced non-inhibitory 'hairpin' conformation. A recently published crystal structure of the F1 domain of the C. thermarum TA2.A1 F1Fo ATP synthase revealed a mutant ɛ subunit lacking the ability to bind ATP in a hairpin conformation. This is a surprising observation considering it is an organism that performs no ATP hydrolysis in vivo, and appears to challenge the current dogma on the regulatory role of the ɛ subunit. This has prompted a re-examination of present knowledge of the ɛ subunits role in different organisms. Here, we compare published biochemical, biophysical and structural data involving ɛ subunit-mediated ATP hydrolysis regulation in a variety of organisms, concluding that the ɛ subunit from the bacterial F-type ATP synthases is indeed capable of regulating ATP hydrolysis activity in a wide variety of bacteria, making it a potentially valuable drug target, but its exact role is still under debate.
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Affiliation(s)
- Alexander Krah
- School of Computational Sciences, Korea Institute for Advanced Study, 85 Hoegiro Dongdaemun-gu, Seoul 02455, Republic of Korea
| | - Mariel Zarco-Zavala
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Duncan G G McMillan
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, Delft 2629 HZ, The Netherlands
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9
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D'Alessandro M, Turina P, Melandri BA, Dunn SD. Modulation of coupling in the Escherichia coli ATP synthase by ADP and P i: Role of the ε subunit C-terminal domain. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1858:34-44. [PMID: 27751906 DOI: 10.1016/j.bbabio.2016.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 08/06/2016] [Accepted: 10/13/2016] [Indexed: 01/28/2023]
Abstract
The ε-subunit of ATP-synthase is an endogenous inhibitor of the hydrolysis activity of the complex and its α-helical C-terminal domain (εCTD) undergoes drastic changes among at least two different conformations. Even though this domain is not essential for ATP synthesis activity, there is evidence for its involvement in the coupling mechanism of the pump. Recently, it was proposed that coupling of the ATP synthase can vary as a function of ADP and Pi concentration. In the present work, we have explored the possible role of the εCTD in this ADP- and Pi-dependent coupling, by examining an εCTD-lacking mutant of Escherichia coli. We show that the loss of Pi-dependent coupling can be observed also in the εCTD-less mutant, but the effects of Pi on both proton pumping and ATP hydrolysis were much weaker in the mutant than in the wild-type. We also show that the εCTD strongly influences the binding of ADP to a very tight binding site (half-maximal effect≈1nM); binding at this site induces higher coupling in EFOF1 and increases responses to Pi. It is proposed that one physiological role of the εCTD is to regulate the kinetics and affinity of ADP/Pi binding, promoting ADP/Pi-dependent coupling.
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Affiliation(s)
- M D'Alessandro
- Department of Biology, Laboratory of Biochemistry and Biophysics, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - P Turina
- Department of Biology, Laboratory of Biochemistry and Biophysics, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy.
| | - B A Melandri
- Department of Biology, Laboratory of Biochemistry and Biophysics, University of Bologna, Via Irnerio 42, 40126 Bologna, Italy
| | - S D Dunn
- Department of Biochemistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
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10
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Kato-Yamada Y. High affinity nucleotide-binding mutant of the ε subunit of thermophilic F1-ATPase. Biochem Biophys Res Commun 2015; 469:1129-32. [PMID: 26746006 DOI: 10.1016/j.bbrc.2015.12.121] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 12/28/2015] [Indexed: 10/22/2022]
Abstract
Specific ATP binding to the ε subunit of thermophilic F1-ATPase has been utilized for the biosensors of ATP in vivo. I report here that the ε subunit containing R103A/R115A mutations can bind ATP with a dissociation constant at 52 nM, which is two orders of magnitude higher affinity than the wild type. The mutant retained specificity for ATP; ADP and GTP bound to the mutant with dissociation constants 16 and 53 μM, respectively. Thus, the mutant would be a good platform for various types of nucleotide biosensor with appropriate modifications.
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Affiliation(s)
- Yasuyuki Kato-Yamada
- Department of Life Science, College of Science, Rikkyo University, Japan; Research Center for Life Science, College of Science, Rikkyo University, Japan.
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11
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Rodriguez AD, Dunn SD, Konermann L. ATP-induced dimerization of the F0F1 ε subunit from Bacillus PS3: a hydrogen exchange-mass spectrometry study. Biochemistry 2014; 53:4072-80. [PMID: 24870150 DOI: 10.1021/bi5004684] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
F0F1 ATP synthase harnesses a transmembrane electrochemical gradient for the production of ATP. When operated in reverse, this multiprotein complex catalyzes ATP hydrolysis. In bacteria, the ε subunit is involved in regulating this ATPase activity. Also, ε is essential for coupling ATP hydrolysis (or synthesis) to proton translocation. The ε subunit consists of a β sandwich and two C-terminal helices, α1 and α2. The protein can switch from a compact fold to an alternate conformation where α1 and α2 are separated, resulting in an extended structure. ε from the thermophile Bacillus PS3 (Tε) binds ATP with high affinity such that this protein may function as an intracellular ATP level sensor. ATP binding to isolated Tε triggers a major conformational transition. Earlier data were interpreted in terms of an ATP + Tεextended → ATP·Tεcompact transition that may mimic aspects of the regulatory switching within F0F1 (Yagi et al. (2007) Proc. Natl. Acad. Sci. U.S.A., 104, 11233–11238). In this work, we employ complementary biophysical techniques for examining the ATP-induced conformational switching of isolated Tε. CD spectroscopy confirmed the occurrence of a large-scale conformational transition upon ATP binding, consistent with the formation of stable helical structure. Hydrogen/deuterium exchange (HDX) mass spectrometry revealed that this transition is accompanied by a pronounced stabilization in the vicinity of the ATP-binding pocket. Surprisingly, dramatic stabilization is also seen in the β8−β9 region, which is remote from the site of ATP interaction. Analytical ultracentrifugation uncovered a previously unrecognized feature of Tε: a high propensity to undergo dimerization in the presence of ATP. Comparison with existing crystallography data strongly suggests that the unexpected β8−β9 HDX protection is due to newly formed protein–protein contacts. Hence, ATP binding to isolated Tε proceeds according to 2ATP + 2Tεextended → (ATP·Tεcompact)2. Implications of this dimerization propensity for the possible role of Tε as an antibiotic target are discussed.
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12
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Malyan AN. Noncatalytic nucleotide binding sites: properties and mechanism of involvement in ATP synthase activity regulation. BIOCHEMISTRY (MOSCOW) 2014; 78:1512-23. [PMID: 24490737 DOI: 10.1134/s0006297913130099] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
ATP synthases (FoF1-ATPases) of chloroplasts, mitochondria, and bacteria catalyze ATP synthesis or hydrolysis coupled with the transmembrane transfer of protons or sodium ions. Their activity is regulated through their reversible inactivation resulting from a decreased transmembrane potential difference. The inactivation is believed to conserve ATP previously synthesized under conditions of sufficient energy supply against unproductive hydrolysis. This review is focused on the mechanism of nucleotide-dependent regulation of the ATP synthase activity where the so-called noncatalytic nucleotide binding sites are involved. Properties of these sites varying upon free enzyme transition to its membrane-bound form, their dependence on membrane energization, and putative mechanisms of noncatalytic site-mediated regulation of the ATP synthase activity are discussed.
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Affiliation(s)
- A N Malyan
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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13
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Lu P, Lill H, Bald D. ATP synthase in mycobacteria: special features and implications for a function as drug target. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1208-18. [PMID: 24513197 DOI: 10.1016/j.bbabio.2014.01.022] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 10/25/2022]
Abstract
ATP synthase is a ubiquitous enzyme that is largely conserved across the kingdoms of life. This conservation is in accordance with its central role in chemiosmotic energy conversion, a pathway utilized by far by most living cells. On the other hand, in particular pathogenic bacteria whilst employing ATP synthase have to deal with energetically unfavorable conditions such as low oxygen tensions in the human host, e.g. Mycobacterium tuberculosis can survive in human macrophages for an extended time. It is well conceivable that such ATP synthases may carry idiosyncratic features that contribute to efficient ATP production. In this review genetic and biochemical data on mycobacterial ATP synthase are discussed in terms of rotary catalysis, stator composition, and regulation of activity. ATP synthase in mycobacteria is of particular interest as this enzyme has been validated as a target for promising new antibacterial drugs. A deeper understanding of the working of mycobacterial ATP synthase and its atypical features can provide insight in adaptations of bacterial energy metabolism. Moreover, pinpointing and understanding critical differences as compared with human ATP synthase may provide input for the design and development of selective ATP synthase inhibitors as antibacterials. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.
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Affiliation(s)
- Ping Lu
- Department of Molecular Cell Biology, AIMMS, Faculty of Earth- and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Holger Lill
- Department of Molecular Cell Biology, AIMMS, Faculty of Earth- and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Dirk Bald
- Department of Molecular Cell Biology, AIMMS, Faculty of Earth- and Life Sciences, VU University Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
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14
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ε subunit of Bacillus subtilis F1-ATPase relieves MgADP inhibition. PLoS One 2013; 8:e73888. [PMID: 23967352 PMCID: PMC3742539 DOI: 10.1371/journal.pone.0073888] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/23/2013] [Indexed: 11/19/2022] Open
Abstract
MgADP inhibition, which is considered as a part of the regulatory system of ATP synthase, is a well-known process common to all F1-ATPases, a soluble component of ATP synthase. The entrapment of inhibitory MgADP at catalytic sites terminates catalysis. Regulation by the ε subunit is a common mechanism among F1-ATPases from bacteria and plants. The relationship between these two forms of regulatory mechanisms is obscure because it is difficult to distinguish which is active at a particular moment. Here, using F1-ATPase from Bacillus subtilis (BF1), which is strongly affected by MgADP inhibition, we can distinguish MgADP inhibition from regulation by the ε subunit. The ε subunit did not inhibit but activated BF1. We conclude that the ε subunit relieves BF1 from MgADP inhibition.
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