1
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Negi A, Perveen S, Gupta R, Singh PP, Sharma R. Unraveling Dilemmas and Lacunae in the Escalating Drug Resistance of Mycobacterium tuberculosis to Bedaquiline, Delamanid, and Pretomanid. J Med Chem 2024; 67:2264-2286. [PMID: 38351709 DOI: 10.1021/acs.jmedchem.3c01892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Delamanid, bedaquiline, and pretomanid have been recently added in the anti-tuberculosis (anti-TB) treatment regimens and have emerged as potential solutions for combating drug-resistant TB. These drugs have proven to be effective in treating drug-resistant TB when used in combination. However, concerns have been raised about the eventual loss of these drugs due to evolving resistance mechanisms and certain adverse effects such as prolonged QT period, gastrointestinal problems, hepatotoxicity, and renal disorders. This Perspective emphasizes the properties of these first-in-class drugs, including their mechanism of action, pharmacokinetics/pharmacodynamics profiles, clinical studies, adverse events, and underlying resistance mechanisms. A brief coverage of efforts toward the generation of best-in-class leads in each class is also provided. The ongoing clinical trials of new combinations of these drugs are discussed, thus providing a better insight into the use of these drugs while designing an effective treatment regimen for resistant TB cases.
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Affiliation(s)
- Anjali Negi
- Infectious Diseases Division, CSIR - Indian Institute of Integrative Medicine, Jammu-180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Summaya Perveen
- Infectious Diseases Division, CSIR - Indian Institute of Integrative Medicine, Jammu-180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Ria Gupta
- Natural Products and Medicinal Chemistry, CSIR - Indian Institute of Integrative Medicine, Jammu-180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Parvinder Pal Singh
- Natural Products and Medicinal Chemistry, CSIR - Indian Institute of Integrative Medicine, Jammu-180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Rashmi Sharma
- Infectious Diseases Division, CSIR - Indian Institute of Integrative Medicine, Jammu-180001, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
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2
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Saw WG, Le KCM, Shin J, Kwek JHM, Wong CF, Ragunathan P, Fong TC, Müller V, Grüber G. Atomic insights of an up and down conformation of the Acinetobacter baumannii F 1 -ATPase subunit ε and deciphering the residues critical for ATP hydrolysis inhibition and ATP synthesis. FASEB J 2023; 37:e23040. [PMID: 37318822 DOI: 10.1096/fj.202300175rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 05/23/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023]
Abstract
The Acinetobacter baumannii F1 FO -ATP synthase (α3 :β3 :γ:δ:ε:a:b2 :c10 ), which is essential for this strictly respiratory opportunistic human pathogen, is incapable of ATP-driven proton translocation due to its latent ATPase activity. Here, we generated and purified the first recombinant A. baumannii F1 -ATPase (AbF1 -ATPase) composed of subunits α3 :β3 :γ:ε, showing latent ATP hydrolysis. A 3.0 Å cryo-electron microscopy structure visualizes the architecture and regulatory element of this enzyme, in which the C-terminal domain of subunit ε (Abε) is present in an extended position. An ε-free AbF1 -ɑβγ complex generated showed a 21.5-fold ATP hydrolysis increase, demonstrating that Abε is the major regulator of AbF1 -ATPase's latent ATP hydrolysis. The recombinant system enabled mutational studies of single amino acid substitutions within Abε or its interacting subunits β and γ, respectively, as well as C-terminal truncated mutants of Abε, providing a detailed picture of Abε's main element for the self-inhibition mechanism of ATP hydrolysis. Using a heterologous expression system, the importance of Abε's C-terminus in ATP synthesis of inverted membrane vesicles, including AbF1 FO -ATP synthases, has been explored. In addition, we are presenting the first NMR solution structure of the compact form of Abε, revealing interaction of its N-terminal β-barrel and C-terminal ɑ-hairpin domain. A double mutant of Abε highlights critical residues for Abε's domain-domain formation which is important also for AbF1 -ATPase's stability. Abε does not bind MgATP, which is described to regulate the up and down movements in other bacterial counterparts. The data are compared to regulatory elements of F1 -ATPases in bacteria, chloroplasts, and mitochondria to prevent wasting of ATP.
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Affiliation(s)
- Wuan-Geok Saw
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
- NTU Institute of Structural Biology, Nanyang Technological University, Singapore, Singapore
| | - Khoa Cong Minh Le
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Joon Shin
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Jes Hui Min Kwek
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Chui Fann Wong
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Priya Ragunathan
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Tuck Choy Fong
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Volker Müller
- Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt, Germany
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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3
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Wong CF, Leow CY, Grüber G. Cryo-EM structure of the Mycobacterium abscessus F 1-ATPase. Biochem Biophys Res Commun 2023; 671:140-145. [PMID: 37302287 DOI: 10.1016/j.bbrc.2023.05.095] [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: 05/02/2023] [Revised: 05/14/2023] [Accepted: 05/24/2023] [Indexed: 06/13/2023]
Abstract
The cases of lung disease caused by non-tuberculous mycobacterium Mycobacterium abscessus (Mab) are increasing and not reliably curable. Repurposing of anti-tuberculosis inhibitors brought the oxidative phosphorylation pathway with its final product ATP, formed by the essential F1FO-ATP synthase (subunits α3:β3:γ:δ:ε:a:b:b':c9), into focus as an attractive inhibitor target against Mab. Because of the pharmacological attractiveness of this enzyme, we generated and purified a recombinant and enzymatically active Mab F1-ATPase complex, including subunits α3:β3:γ:δ:ε (MabF1-αβγδε) to achieve mechanistic, regulatory, and structural insights. The high purity of the complex enabled the first cryo-electron microscopy structure determination of the Mab F1-ATPase complex to 7.3 Å resolution. The enzyme showed low ATP hydrolysis activity, which was stimulated by trypsin treatment. No effect was observed in the presence of the detergent lauryldimethylamine oxide.
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Affiliation(s)
- Chui-Fann Wong
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Chen-Yen Leow
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Gerhard Grüber
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore.
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4
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Kelam LM, Wani MA, Dhaked DK. An update on ATP synthase inhibitors: A unique target for drug development in M. tuberculosis. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 180-181:87-104. [PMID: 37105260 DOI: 10.1016/j.pbiomolbio.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023]
Abstract
ATP synthase is a key protein in the oxidative phosphorylation process, as it aids in the effective production of ATP (Adenosine triphosphate) in all life's of kingdoms. ATP synthases have distinctive properties that contribute to efficient ATP synthesis. The ATP synthase of mycobacterium is of special relevance since it has been identified as a target for potential anti-TB molecules, especially Bedaquiline (BDQ). Better knowledge of how mycobacterial ATP synthase functions and its peculiar characteristics will aid in our understanding of bacterial energy metabolism adaptations. Furthermore, identifying and understanding the important distinctions between human ATP synthase and bacterial ATP synthase may provide insight into the design and development of inhibitors that target specific ATP synthase. In recent years, many potential candidates targeting the ATP synthase of mycobacterium have been developed. In this review, we discuss the druggable targets of the Electron transport chain (ETC) and recently identified potent inhibitors (including clinical molecules) from 2015 to 2022 of diverse classes that target ATP synthase of M. tuberculosis.
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Affiliation(s)
- Lakshmi Mounika Kelam
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India
| | - Mushtaq Ahmad Wani
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India
| | - Devendra K Dhaked
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India.
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5
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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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6
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Structural Elements Involved in ATP Hydrolysis Inhibition and ATP Synthesis of Tuberculosis and Nontuberculous Mycobacterial F-ATP Synthase Decipher New Targets for Inhibitors. Antimicrob Agents Chemother 2022; 66:e0105622. [PMID: 36445139 PMCID: PMC9764993 DOI: 10.1128/aac.01056-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The F1FO-ATP synthase is required for the viability of tuberculosis (TB) and nontuberculous mycobacteria (NTM) and has been validated as a drug target. Here, we present the cryo-EM structures of the Mycobacterium smegmatis F1-ATPase and the F1FO-ATP synthase with different nucleotide occupation within the catalytic sites and visualize critical elements for latent ATP hydrolysis and efficient ATP synthesis. Mutational studies reveal that the extended C-terminal domain (αCTD) of subunit α is the main element for the self-inhibition mechanism of ATP hydrolysis for TB and NTM bacteria. Rotational studies indicate that the transition between the inhibition state by the αCTD and the active state is a rapid process. We demonstrate that the unique mycobacterial γ-loop and subunit δ are critical elements required for ATP formation. The data underline that these mycobacterium-specific elements of α, γ, and δ are attractive targets, providing a platform for the discovery of species-specific inhibitors.
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7
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Shin J, Harikishore A, Wong CF, Ragunathan P, Thomas D, Grüber G. Atomic solution structure of Mycobacterium abscessus F-ATP synthase subunit ε and identification of Ep1MabF1 as a targeted inhibitor. FEBS J 2022; 289:6308-6323. [PMID: 35612822 PMCID: PMC10609657 DOI: 10.1111/febs.16536] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 04/27/2022] [Accepted: 05/24/2022] [Indexed: 11/30/2022]
Abstract
Mycobacterium abscessus (Mab) is a nontuberculous mycobacterium of increasing clinical relevance. The rapidly growing opportunistic pathogen is intrinsically multi-drug-resistant and causes difficult-to-cure lung disease. Adenosine triphosphate, generated by the essential F1 FO ATP synthase, is the major energy currency of the pathogen, bringing this enzyme complex into focus for the discovery of novel antimycobacterial compounds. Coupling of proton translocation through the membrane-embedded FO sector and ATP formation in the F1 headpiece of the bipartite F1 FO ATP synthase occurs via the central stalk subunits γ and ε. Here, we used solution NMR spectroscopy to resolve the first atomic structure of the Mab subunit ε (Mabε), showing that it consists of an N-terminal β-barrel domain (NTD) and a helix-loop-helix motif in its C-terminal domain (CTD). NMR relaxation measurements of Mabε shed light on dynamic epitopes and amino acids relevant for coupling processes within the protein. We describe structural differences between other mycobacterial ε subunits and Mabε's lack of ATP binding. Based on the structural insights, we conducted an in silico inhibitor screen. One hit, Ep1MabF1, was shown to inhibit the growth of Mab and bacterial ATP synthesis. NMR titration experiments and docking studies described the binding epitopes of Ep1MabF1 on Mabε. Together, our data demonstrate the potential to develop inhibitors targeting the ε subunit of Mab F1 FO ATP synthase to interrupt the coupling process.
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Affiliation(s)
- Joon Shin
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Amaravadhi Harikishore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Chui Fann Wong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Priya Ragunathan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Dick Thomas
- Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, NJ 07110, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, 123 Metro Boulevard, Nutley, NJ 07110, USA
- Department of Microbiology and Immunology, Georgetown University, 3900 Reservoir Road NW Medical-Dental Building, Washington, DC 20007, USA
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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8
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Anand P, Akhter Y. A review on enzyme complexes of electron transport chain from Mycobacterium tuberculosis as promising drug targets. Int J Biol Macromol 2022; 212:474-494. [PMID: 35613677 DOI: 10.1016/j.ijbiomac.2022.05.124] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/05/2022] [Accepted: 05/17/2022] [Indexed: 12/20/2022]
Abstract
Energy metabolism is a universal process occurring in all life forms. In Mycobacterium tuberculosis (Mtb), energy production is carried out in two possible ways, oxidative phosphorylation (OxPhos) and substrate-level phosphorylation. Mtb is an obligate aerobic bacterium, making it dependent on OxPhos for ATP synthesis and growth. Mtb inhabits varied micro-niches during the infection cycle, outside and within the host cells, which alters its primary metabolic pathways during the pathogenesis. In this review, we discuss cellular respiration in the context of the mechanism and structural importance of the proteins and enzyme complexes involved. These protein-protein complexes have been proven to be essential for Mtb virulence as they aid the bacteria's survival during aerobic and hypoxic conditions. ATP synthase, a crucial component of the electron transport chain, has been in the limelight, as a prominent drug target against tuberculosis. Likewise, in this review, we have explored other protein-protein complexes of the OxPhos pathway, their functional essentiality, and their mechanism in Mtb's diverse lifecycle. The review summarises crucial target proteins and reported inhibitors of the electron transport chain pathway of Mtb.
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Affiliation(s)
- Pragya Anand
- Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, Uttar Pradesh 226025, India
| | - Yusuf Akhter
- Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Lucknow, Uttar Pradesh 226025, India.
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9
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Harikishore A, Saw WG, Ragunathan P, Litty D, Dick T, Müller V, Grüber G. Mutational Analysis of Mycobacterial F-ATP Synthase Subunit δ Leads to a Potent δ Enzyme Inhibitor. ACS Chem Biol 2022; 17:529-535. [PMID: 35148057 DOI: 10.1021/acschembio.1c00766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While many bacteria are able to bypass the requirement for oxidative phosphorylation when grown on carbohydrates, Mycobacterium tuberculosis is unable to do so. Differences of amino acid composition and structural features of the mycobacterial F-ATP synthase (α3:β3:γ:δ:ε:a:b:b':c9) compared to its prokaryotic or human counterparts were recently elucidated and paved avenues for the discovery of molecules interfering with various regulative mechanisms of this essential energy converter. In this context, the mycobacterial peripheral stalk subunit δ came into focus, which displays a unique N-terminal 111-amino acid extension. Here, mutants of recombinant mycobacterial subunit δ were characterized, revealing significant reduction in ATP synthesis and demonstrating essentiality of this subunit for effective catalysis. These results provided the basis for the generation of a four-feature model forming a δ receptor-based pharmacophore and to identify a potent subunit δ inhibitor DeMF1 via in silico screening. The successful targeting of the δ subunit demonstrates the potential to advance δ's flexible coupling as a new area for the development of F-ATP synthase inhibitors.
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Affiliation(s)
- Amaravadhi Harikishore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Wuan-Geok Saw
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Priya Ragunathan
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Dennis Litty
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health, 111 Ideation Way, Nutley, New Jersey 07110, United States
- Medical Sciences, Hackensack Meridian School of Medicine, 123 Metro Boulevard, Nutley, New Jersey 07110, United States
- Department of Microbiology and Immunology, Georgetown University, 3900 Reservoir Road NW Medical-Dental Building, Washington, D.C. 20007, United States
| | - Volker Müller
- Molecular Microbiology and Bioenergetics, Institute of Molecular Biosciences Johann Wolfgang Goethe University Frankfurt/Main, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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10
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Inhibitors of F 1F 0-ATP synthase enzymes for the treatment of tuberculosis and cancer. Future Med Chem 2021; 13:911-926. [PMID: 33845594 DOI: 10.4155/fmc-2021-0010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The spectacular success of the mycobacterial F1F0-ATP synthase inhibitor bedaquiline for the treatment of drug-resistant tuberculosis has generated wide interest in the development of other inhibitors of this enzyme. Work in this realm has included close analogues of bedaquiline with better safety profiles and 'bedaquiline-like' compounds, some of which show potent antibacterial activity in vitro although none have yet progressed to clinical trials. The search has lately extended to a range of new scaffolds as potential inhibitors, including squaramides, diaminoquinazolines, chloroquinolines, dihydropyrazolo[1,5-a]pyrazin-4-ones, thiazolidinediones, diaminopyrimidines and tetrahydroquinolines. Because of the ubiquitous expression of ATP synthase enzymes, there has also been interest in inhibitors of other bacterial ATP synthases, as well as inhibitors of human mitochondrial ATP synthase for cancer therapy. The latter encompass both complex natural products and simpler small molecules. The review seeks to demonstrate the breadth of the structural types of molecules able to effectively inhibit the function of variants of this intriguing enzyme.
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11
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The Unique C-Terminal Extension of Mycobacterial F-ATP Synthase Subunit α Is the Major Contributor to Its Latent ATP Hydrolysis Activity. Antimicrob Agents Chemother 2020; 64:AAC.01568-20. [PMID: 32988828 DOI: 10.1128/aac.01568-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/16/2020] [Indexed: 01/03/2023] Open
Abstract
Mycobacterial F1Fo-ATP synthases (α3:β3:γ:δ:ε:a:b:b':c9 ) are incapable of ATP-driven proton translocation due to their latent ATPase activity. This prevents wasting of ATP and altering of the proton motive force, whose dissipation is lethal to mycobacteria. We demonstrate that the mycobacterial C-terminal extension of nucleotide-binding subunit α contributes mainly to the suppression of ATPase activity in the recombinant mycobacterial F1-ATPase. Using C-terminal deletion mutants, the regions responsible for the enzyme's latency were mapped, providing a new compound epitope.
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12
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Shin J, Singal B, Sony Subramanian Manimekalai M, Wei Chen M, Ragunathan P, Grüber G. Atomic structure of, and valine binding to the regulatory ACT domain of the Mycobacterium tuberculosis Rel protein. FEBS J 2020; 288:2377-2397. [PMID: 33067840 DOI: 10.1111/febs.15600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 09/14/2020] [Accepted: 10/07/2020] [Indexed: 12/30/2022]
Abstract
The stringent response, regulated by the bifunctional (p)ppGpp synthetase/hydrolase Rel in mycobacteria, is critical for long-term survival of the drug-tolerant dormant state of Mycobacterium tuberculosis. During amino acid starvation, MtRel senses a drop in amino acid concentration and synthesizes the messengers pppGpp and ppGpp, collectively called (p)ppGpp. Here, we investigate the role of the regulatory 'Aspartokinase, Chorismate mutase and TyrA' (ACT) domain in MtRel. Using NMR spectroscopy approaches, we report the high-resolution structure of dimeric MtRel ACT which selectively binds to valine out of all other branched-chain amino acids tested. A set of MtRel ACT mutants were generated to identify the residues required for maintaining the head-to-tail dimer. Through NMR titrations, we determined the crucial residues for binding of valine and show structural rearrangement of the MtRel ACT dimer in the presence of valine. This study suggests the direct involvement of amino acids in (p)ppGpp accumulation mediated by MtRel independent to interactions with stalled ribosomes. Database Structural data are available in the PDB database under the accession number 6LXG.
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Affiliation(s)
- Joon Shin
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Bharti Singal
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | | | - Ming Wei Chen
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Priya Ragunathan
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
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13
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Advances in antibiotic drug discovery: reducing the barriers for antibiotic development. Future Med Chem 2020; 12:2067-2087. [PMID: 33124460 DOI: 10.4155/fmc-2020-0247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Antibiotic drug discovery has been an essential field of research since the early 1900s, but the threat from infectious bacteria has only increased over the decades because of the emergence of widespread multidrug resistance. In this review, we discuss the recent advances in natural product, computational and medicinal chemistry that have reinvigorated the field of antibiotic drug discovery while giving perspective on how easily, both in cost and in expertise, these methods can be implemented by other researchers with the goal of increasing the number of scientists contributing to this public health crisis.
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14
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Wong CF, Lau AM, Harikishore A, Saw WG, Shin J, Ragunathan P, Bhushan S, Ngan SFC, Sze SK, Bates RW, Dick T, Grüber G. A systematic assessment of mycobacterial F 1 -ATPase subunit ε's role in latent ATPase hydrolysis. FEBS J 2020; 288:818-836. [PMID: 32525613 DOI: 10.1111/febs.15440] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 05/05/2020] [Accepted: 06/03/2020] [Indexed: 12/20/2022]
Abstract
In contrast to most bacteria, the mycobacterial F1 FO -ATP synthase (α3 :β3 :γ:δ:ε:a:b:b':c9 ) does not perform ATP hydrolysis-driven proton translocation. Although subunits α, γ and ε of the catalytic F1 -ATPase component α3 :β3 :γ:ε have all been implicated in the suppression of the enzyme's ATPase activity, the mechanism remains poorly defined. Here, we brought the central stalk subunit ε into focus by generating the recombinant Mycobacterium smegmatis F1 -ATPase (MsF1 -ATPase), whose 3D low-resolution structure is presented, and its ε-free form MsF1 αβγ, which showed an eightfold ATP hydrolysis increase and provided a defined system to systematically study the segments of mycobacterial ε's suppression of ATPase activity. Deletion of four amino acids at ε's N terminus, mutant MsF1 αβγεΔ2-5 , revealed similar ATP hydrolysis as MsF1 αβγ. Together with biochemical and NMR solution studies of a single, double, triple and quadruple N-terminal ε-mutants, the importance of the first N-terminal residues of mycobacterial ε in structure stability and latency is described. Engineering ε's C-terminal mutant MsF1 αβγεΔ121 and MsF1 αβγεΔ103-121 with deletion of the C-terminal residue D121 and the two C-terminal ɑ-helices, respectively, revealed the requirement of the very C terminus for communication with the catalytic α3 β3 -headpiece and its function in ATP hydrolysis inhibition. Finally, we applied the tools developed during the study for an in silico screen to identify a novel subunit ε-targeting F-ATP synthase inhibitor.
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Affiliation(s)
- Chui-Fann Wong
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Aik-Meng Lau
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Amaravadhi Harikishore
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Wuan-Geok Saw
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Joon Shin
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Priya Ragunathan
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Shashi Bhushan
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University, Singapore City, Singapore
| | - So-Fong Cam Ngan
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Roderick W Bates
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore City, Singapore
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore City, Singapore.,Department of Medical Sciences, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, NJ, USA
| | - Gerhard Grüber
- School of Biological Sciences, Nanyang Technological University, Singapore City, Singapore
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15
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Hotra A, Ragunathan P, Ng PS, Seankongsuk P, Harikishore A, Sarathy JP, Saw W, Lakshmanan U, Sae‐Lao P, Kalia NP, Shin J, Kalyanasundaram R, Anbarasu S, Parthasarathy K, Pradeep CN, Makhija H, Dröge P, Poulsen A, Tan JHL, Pethe K, Dick T, Bates RW, Grüber G. Discovery of a Novel Mycobacterial F‐ATP Synthase Inhibitor and its Potency in Combination with Diarylquinolines. Angew Chem Int Ed Engl 2020; 59:13295-13304. [DOI: 10.1002/anie.202002546] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Indexed: 01/08/2023]
Affiliation(s)
- Adam Hotra
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
- Nanyang Institute of Technology in Health and Medicine Interdisciplinary Graduate School Nanyang Technological University Republic of Singapore
| | - Priya Ragunathan
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Pearly Shuyi Ng
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Pattarakiat Seankongsuk
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Amaravadhi Harikishore
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Jickky Palmae Sarathy
- Department of Microbiology and Immunology Yong Loo Lin School of Medicine National University of Singapore 14 Medical Drive Singapore 117599 Republic of Singapore
| | - Wuan‐Geok Saw
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Umayal Lakshmanan
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Patcharaporn Sae‐Lao
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Nitin Pal Kalia
- Lee Kong Chian School of Medicine Nanyang Technological University Experimental Medicine Building Republic of Singapore
| | - Joon Shin
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Revathy Kalyanasundaram
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Sivaraj Anbarasu
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Krupakar Parthasarathy
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Chaudhari Namrata Pradeep
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Harshyaa Makhija
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Peter Dröge
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Anders Poulsen
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Jocelyn Hui Ling Tan
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Kevin Pethe
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
- Lee Kong Chian School of Medicine Nanyang Technological University Experimental Medicine Building Republic of Singapore
| | - Thomas Dick
- Department of Microbiology and Immunology Yong Loo Lin School of Medicine National University of Singapore 14 Medical Drive Singapore 117599 Republic of Singapore
- Center for Discovery and Innovation Hackensack Meridian Health 340 Kingsland Street Nutley NJ 07110 USA
| | - Roderick W. Bates
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Gerhard Grüber
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
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16
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Hotra A, Ragunathan P, Ng PS, Seankongsuk P, Harikishore A, Sarathy JP, Saw W, Lakshmanan U, Sae‐Lao P, Kalia NP, Shin J, Kalyanasundaram R, Anbarasu S, Parthasarathy K, Pradeep CN, Makhija H, Dröge P, Poulsen A, Tan JHL, Pethe K, Dick T, Bates RW, Grüber G. Discovery of a Novel Mycobacterial F‐ATP Synthase Inhibitor and its Potency in Combination with Diarylquinolines. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202002546] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Adam Hotra
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
- Nanyang Institute of Technology in Health and Medicine Interdisciplinary Graduate School Nanyang Technological University Republic of Singapore
| | - Priya Ragunathan
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Pearly Shuyi Ng
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Pattarakiat Seankongsuk
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Amaravadhi Harikishore
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Jickky Palmae Sarathy
- Department of Microbiology and Immunology Yong Loo Lin School of Medicine National University of Singapore 14 Medical Drive Singapore 117599 Republic of Singapore
| | - Wuan‐Geok Saw
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Umayal Lakshmanan
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Patcharaporn Sae‐Lao
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Nitin Pal Kalia
- Lee Kong Chian School of Medicine Nanyang Technological University Experimental Medicine Building Republic of Singapore
| | - Joon Shin
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Revathy Kalyanasundaram
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Sivaraj Anbarasu
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Krupakar Parthasarathy
- Centre for Drug Discovery and Development Sathyabama Institute of Science and Technology Chennai 600119 India
| | - Chaudhari Namrata Pradeep
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Harshyaa Makhija
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Peter Dröge
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
| | - Anders Poulsen
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Jocelyn Hui Ling Tan
- Experimental Drug Development Centre Agency for Science Technology and Research, A*STAR 10 Biopolis Road Singapore 138670 Republic of Singapore
| | - Kevin Pethe
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
- Lee Kong Chian School of Medicine Nanyang Technological University Experimental Medicine Building Republic of Singapore
| | - Thomas Dick
- Department of Microbiology and Immunology Yong Loo Lin School of Medicine National University of Singapore 14 Medical Drive Singapore 117599 Republic of Singapore
- Center for Discovery and Innovation Hackensack Meridian Health 340 Kingsland Street Nutley NJ 07110 USA
| | - Roderick W. Bates
- School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Republic of Singapore
| | - Gerhard Grüber
- School of Biological Sciences Nanyang Technological University 60 Nanyang Drive Singapore 637551 Republic of Singapore
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17
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Oxidative Phosphorylation—an Update on a New, Essential Target Space for Drug Discovery in Mycobacterium tuberculosis. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10072339] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
New drugs with new mechanisms of action are urgently required to tackle the global tuberculosis epidemic. Following the FDA-approval of the ATP synthase inhibitor bedaquiline (Sirturo®), energy metabolism has become the subject of intense focus as a novel pathway to exploit for tuberculosis drug development. This enthusiasm stems from the fact that oxidative phosphorylation (OxPhos) and the maintenance of the transmembrane electrochemical gradient are essential for the viability of replicating and non-replicating Mycobacterium tuberculosis (M. tb), the etiological agent of human tuberculosis (TB). Therefore, new drugs targeting this pathway have the potential to shorten TB treatment, which is one of the major goals of TB drug discovery. This review summarises the latest and key findings regarding the OxPhos pathway in M. tb and provides an overview of the inhibitors targeting various components. We also discuss the potential of new regimens containing these inhibitors, the flexibility of this pathway and, consequently, the complexity in targeting it. Lastly, we discuss opportunities and future directions of this drug target space.
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18
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Milgrom YM, Duncan TM. F-ATP-ase of Escherichia coli membranes: The ubiquitous MgADP-inhibited state and the inhibited state induced by the ε-subunit's C-terminal domain are mutually exclusive. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148189. [PMID: 32194063 DOI: 10.1016/j.bbabio.2020.148189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 03/10/2020] [Accepted: 03/13/2020] [Indexed: 12/21/2022]
Abstract
ATP synthases are important energy-coupling, rotary motor enzymes in all kingdoms of life. In all F-type ATP synthases, the central rotor of the catalytic F1 complex is composed of the γ subunit and the N-terminal domain (NTD) of the ε subunit. In the enzymes of diverse bacteria, the C-terminal domain of ε (εCTD) can undergo a dramatic conformational change to trap the enzyme in a transiently inactive state. This inhibitory mechanism is absent in the mitochondrial enzyme, so the εCTD could provide a means to selectively target ATP synthases of pathogenic bacteria for antibiotic development. For Escherichia coli and other bacterial model systems, it has been difficult to dissect the relationship between ε inhibition and a MgADP-inhibited state that is ubiquitous for FOF1 from bacteria and eukaryotes. A prior study with the isolated catalytic complex from E. coli, EcF1, showed that these two modes of inhibition are mutually exclusive, but it has long been known that interactions of F1 with the membrane-embedded FO complex modulate inhibition by the εCTD. Here, we study membranes containing EcFOF1 with wild-type ε, ε lacking the full εCTD, or ε with a small deletion at the C-terminus. By using compounds with distinct activating effects on F-ATP-ase activity, we confirm that εCTD inhibition and ubiquitous MgADP inhibition are mutually exclusive for membrane-bound E. coli F-ATP-ase. We determine that most of the enzyme complexes in wild-type membranes are in the ε-inhibited state (>50%) or in the MgADP-inhibited state (30%).
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Affiliation(s)
- Yakov M Milgrom
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA.
| | - Thomas M Duncan
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, 750 E Adams St, Syracuse, NY 13210, USA.
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19
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TBAJ-876 Displays Bedaquiline-Like Mycobactericidal Potency without Retaining the Parental Drug's Uncoupler Activity. Antimicrob Agents Chemother 2020; 64:AAC.01540-19. [PMID: 31712198 PMCID: PMC6985740 DOI: 10.1128/aac.01540-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/03/2019] [Indexed: 12/22/2022] Open
Abstract
The diarylquinoline F1FO-ATP synthase inhibitor bedaquiline (BDQ) displays protonophore activity. Thus, uncoupling electron transport from ATP synthesis appears to be a second mechanism of action of this antimycobacterial drug. Here, we show that the new BDQ analogue TBAJ-876 did not retain the parental drug’s protonophore activity. Comparative time-kill analyses revealed that both compounds exert the same bactericidal activity. The diarylquinoline F1FO-ATP synthase inhibitor bedaquiline (BDQ) displays protonophore activity. Thus, uncoupling electron transport from ATP synthesis appears to be a second mechanism of action of this antimycobacterial drug. Here, we show that the new BDQ analogue TBAJ-876 did not retain the parental drug’s protonophore activity. Comparative time-kill analyses revealed that both compounds exert the same bactericidal activity. These results suggest that the uncoupler activity is not required for the bactericidal activity of diarylquinolines.
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20
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Re-Understanding the Mechanisms of Action of the Anti-Mycobacterial Drug Bedaquiline. Antibiotics (Basel) 2019; 8:antibiotics8040261. [PMID: 31835707 PMCID: PMC6963887 DOI: 10.3390/antibiotics8040261] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 12/07/2019] [Indexed: 12/14/2022] Open
Abstract
Bedaquiline (BDQ) inhibits ATP generation in Mycobacterium tuberculosis by interfering with the F-ATP synthase activity. Two mechanisms of action of BDQ are broadly accepted. A direct mechanism involves BDQ binding to the enzyme’s c-ring to block its rotation, thus inhibiting ATP synthesis in the enzyme’s catalytic α3β3-headpiece. An indirect mechanism involves BDQ uncoupling electron transport in the electron transport chain from ATP synthesis at the F-ATP synthase. In a recently uncovered second direct mechanism, BDQ binds to the enzyme’s ε-subunit to disrupt its ability to link c-ring rotation to ATP synthesis at the α3β3-headpiece. However, this mechanism is controversial as the drug’s binding affinity for the isolated ε-subunit protein is moderate and spontaneous resistance mutants in the ε-subunit cannot be isolated. Recently, the new, structurally distinct BDQ analogue TBAJ-876 was utilized as a chemical probe to revisit BDQ’s mechanisms of action. In this review, we first summarize discoveries on BDQ’s mechanisms of action and then describe the new insights derived from the studies of TBAJ-876. The TBAJ-876 investigations confirm the c-ring as a target, while also supporting a functional role for targeting the ε-subunit. Surprisingly, the new findings suggest that the uncoupler mechanism does not play a key role in BDQ’s anti-mycobacterial activity.
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21
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Roy KK, Wani MA. Emerging opportunities of exploiting mycobacterial electron transport chain pathway for drug-resistant tuberculosis drug discovery. Expert Opin Drug Discov 2019; 15:231-241. [PMID: 31774006 DOI: 10.1080/17460441.2020.1696771] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Introduction: Tuberculosis (TB) is a leading infectious disease worldwide whose chemotherapy is challenged by the continued rise of drug resistance. This epidemic urges the need to discover anti-TB drugs with novel modes of action.Areas covered: The mycobacterial electron transport chain (ETC) pathway represents a hub of anti-TB drug targets. Herein, the authors highlight the various targets within the mycobacterial ETC and highlight some of the promising ETC-targeted drugs and clinical candidates that have been discovered or repurposed. Furthermore, recent breakthroughs in the availability of X-ray and/or cryo-EM structures of some targets are discussed, and various opportunities of exploiting these structures for the discovery of new anti-TB drugs are emphasized.Expert opinion: The drug discovery efforts targeting the ETC pathway have led to the FDA approval of bedaquiline, a FOF1-ATP synthase inhibitor, and the discovery of Q203, a clinical candidate drug targeting the mycobacterial cytochrome bcc-aa3 supercomplex. Moreover, clofazimine, a proposed prodrug competing with menaquinone for its reduction by mycobacterial NADH dehydrogenase 2, has been repurposed for TB treatment. Recently available structures of the mycobacterial ATP synthase C9 rotary ring and the cytochrome bcc-aa3 supercomplex represent further opportunities for the structure-based drug design (SBDD) of the next-generation of inhibitors against Mycobacterium tuberculosis.
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Affiliation(s)
- Kuldeep K Roy
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
| | - Mushtaq Ahmad Wani
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER), Kolkata, India
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22
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Saw WG, Wong CF, Dick T, Grüber G. Overexpression, purification, enzymatic and microscopic characterization of recombinant mycobacterial F-ATP synthase. Biochem Biophys Res Commun 2019; 522:374-380. [PMID: 31761325 DOI: 10.1016/j.bbrc.2019.11.098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 11/15/2019] [Indexed: 01/16/2023]
Abstract
The F-ATP synthase is an essential enzyme in mycobacteria, including the pathogenic Mycobacterium tuberculosis. Several new compounds in the TB-drug pipeline target the F-ATP synthase. In light of the importance and pharmacological attractiveness of this novel antibiotic target, tools have to be developed to generate a recombinant mycobacterial F1FO ATP synthase to achieve atomic insight and mutants for mechanistic and regulatory understanding as well as structure-based drug design. Here, we report the first genetically engineered, purified and enzymatically active recombinant M. smegmatis F1FO ATP synthase. The projected 2D- and 3D structures of the recombinant enzyme derived from negatively stained electron micrographs are presented. Furthermore, the first 2D projections from cryo-electron images are revealed, paving the way for an atomic resolution structure determination.
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Affiliation(s)
- Wuan-Geok Saw
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Chui-Fann Wong
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA; Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore
| | - Gerhard Grüber
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore, 637551, Republic of Singapore.
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23
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Unique structural and mechanistic properties of mycobacterial F-ATP synthases: Implications for drug design. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 152:64-73. [PMID: 31743686 DOI: 10.1016/j.pbiomolbio.2019.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 09/25/2019] [Accepted: 11/13/2019] [Indexed: 12/31/2022]
Abstract
The causative agent of Tuberculosis (TB) Mycobacterium tuberculosis (Mtb) encounters unfavourable environmental conditions in the lungs, including nutrient limitation, low oxygen tensions and/or low/high pH values. These harsh conditions in the host triggers Mtb to enter a dormant state in which the pathogen does not replicate and uses host-derived fatty acids instead of carbohydrates as an energy source. Independent to the energy source, the bacterium's energy currency ATP is generated by oxidative phosphorylation, in which the F1FO-ATP synthase uses the proton motive force generated by the electron transport chain. This catalyst is essential in Mtb and inhibition by the diarylquinoline class of drugs like Bedaquilline, TBAJ-587, TBAJ-876 or squaramides demonstrated that this engine is an attractive target in TB drug discovery. A special feature of the mycobacterial F-ATP synthase is its inability to establish a significant proton gradient during ATP hydrolysis, and its latent ATPase activity, to prevent energy waste and to control the membrane potential. Recently, unique epitopes of mycobacterial F1FO-ATP synthase subunits absent in their prokaryotic or mitochondrial counterparts have been identified to contribute to the regulation of the low ATPase activity. Most recent structural insights into individual subunits, the F1 domain or the entire mycobacterial enzyme added to the understanding of mechanisms, regulation and differences of the mycobacterial F1FO-ATP synthase compared to other bacterial and eukaryotic engines. These novel insights provide the basis for the design of new compounds targeting this engine and even novel regimens for multidrug resistant TB.
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24
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Disrupting coupling within mycobacterial F-ATP synthases subunit ε causes dysregulated energy production and cell wall biosynthesis. Sci Rep 2019; 9:16759. [PMID: 31727946 PMCID: PMC6856130 DOI: 10.1038/s41598-019-53107-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 10/28/2019] [Indexed: 11/23/2022] Open
Abstract
The dynamic interaction of the N- and C-terminal domains of mycobacterial F-ATP synthase subunit ε is proposed to contribute to efficient coupling of H+-translocation and ATP synthesis. Here, we investigate crosstalk between both subunit ε domains by introducing chromosomal atpC missense mutations in the C-terminal helix 2 of ε predicted to disrupt inter domain and subunit ε-α crosstalk and therefore coupling. The ε mutant εR105A,R111A,R113A,R115A (ε4A) showed decreased intracellular ATP, slower growth rates and lower molar growth yields on non-fermentable carbon sources. Cellular respiration and metabolism were all accelerated in the mutant strain indicative of dysregulated oxidative phosphorylation. The ε4A mutant exhibited an altered colony morphology and was hypersusceptible to cell wall-acting antimicrobials suggesting defective cell wall biosynthesis. In silico screening identified a novel mycobacterial F-ATP synthase inhibitor disrupting ε’s coupling activity demonstrating the potential to advance this regulation as a new area for mycobacterial F-ATP synthase inhibitor development.
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25
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TBAJ-876 Retains Bedaquiline's Activity against Subunits c and ε of Mycobacterium tuberculosis F-ATP Synthase. Antimicrob Agents Chemother 2019; 63:AAC.01191-19. [PMID: 31358589 PMCID: PMC6761534 DOI: 10.1128/aac.01191-19] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/25/2019] [Indexed: 12/18/2022] Open
Abstract
The antituberculosis drug bedaquiline (BDQ) inhibits Mycobacterium tuberculosis F-ATP synthase by interfering with two subunits. Drug binding to the c subunit stalls the rotation of the c ring, while binding to the ε subunit blocks coupling of c ring rotation to ATP synthesis at the catalytic α3:β3 headpiece. BDQ is used for the treatment of drug-resistant tuberculosis. The antituberculosis drug bedaquiline (BDQ) inhibits Mycobacterium tuberculosis F-ATP synthase by interfering with two subunits. Drug binding to the c subunit stalls the rotation of the c ring, while binding to the ε subunit blocks coupling of c ring rotation to ATP synthesis at the catalytic α3:β3 headpiece. BDQ is used for the treatment of drug-resistant tuberculosis. However, the drug is highly lipophilic, displays a long terminal half-life, and has a cardiotoxicity liability by causing QT interval prolongation. Recent medicinal chemistry campaigns have resulted in the discovery of 3,5-dialkoxypyridine analogues of BDQ that are less lipophilic, have higher clearance, and display lower cardiotoxic potential. TBAJ-876, which is a new developmental compound of this series, shows attractive antitubercular activity and efficacy in a murine tuberculosis model. Here, we asked whether TBAJ-876 and selected analogues of the compound retain BDQ’s mechanism of action. Biochemical assays showed that TBAJ-876 is a potent inhibitor of mycobacterial F-ATP synthase. Selection of spontaneous TBAJ-876-resistant mutants identified missense mutations at BDQ’s binding site on the c subunit, suggesting that TBAJ-876 retains BDQ’s targeting of the c ring. Susceptibility testing against a strain overexpressing the ε subunit and a strain harboring an engineered mutation in BDQ’s ε subunit binding site suggest that TBAJ-876 retains BDQ’s activity on the ε subunit. Nuclear magnetic resonance (NMR) titration studies confirmed that TBAJ-876 binds to the ε subunit at BDQ’s binding site. We show that TBAJ-876 retains BDQ’s antimycobacterial mode of action. The developmental compound inhibits the mycobacterial F-ATP synthase via a dual-subunit mechanism of interfering with the functions of both the enzyme’s c and ε subunits.
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26
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Mode-of-action profiling reveals glutamine synthetase as a collateral metabolic vulnerability of M. tuberculosis to bedaquiline. Proc Natl Acad Sci U S A 2019; 116:19646-19651. [PMID: 31501323 DOI: 10.1073/pnas.1907946116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Combination chemotherapy can increase treatment efficacy and suppress drug resistance. Knowledge of how to engineer rational, mechanism-based drug combinations, however, remains lacking. Although studies of drug activity have historically focused on the primary drug-target interaction, growing evidence has emphasized the importance of the subsequent consequences of this interaction. Bedaquiline (BDQ) is the first new drug for tuberculosis (TB) approved in more than 40 y, and a species-selective inhibitor of the Mycobacterium tuberculosis (Mtb) ATP synthase. Curiously, BDQ-mediated killing of Mtb lags significantly behind its inhibition of ATP synthase, indicating a mode of action more complex than the isolated reduction of ATP pools. Here, we report that BDQ-mediated inhibition of Mtb's ATP synthase triggers a complex metabolic response indicative of a specific hierarchy of ATP-dependent reactions. We identify glutamine synthetase (GS) as an enzyme whose activity is most responsive to changes in ATP levels. Chemical supplementation with exogenous glutamine failed to affect BDQ's antimycobacterial activity. However, further inhibition of Mtb's GS synergized with and accelerated the onset of BDQ-mediated killing, identifying Mtb's glutamine synthetase as a collateral, rather than directly antimycobacterial, metabolic vulnerability of BDQ. These findings reveal a previously unappreciated physiologic specificity of ATP and a facet of mode-of-action biology we term collateral vulnerability, knowledge of which has the potential to inform the development of rational, mechanism-based drug combinations.
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Kamariah N, Huber RG, Nartey W, Bhushan S, Bond PJ, Grüber G. Structure and subunit arrangement of Mycobacterial F1FO ATP synthase and novel features of the unique mycobacterial subunit δ. J Struct Biol 2019; 207:199-208. [DOI: 10.1016/j.jsb.2019.05.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 05/21/2019] [Accepted: 05/23/2019] [Indexed: 02/08/2023]
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Petri J, Nakatani Y, Montgomery MG, Ferguson SA, Aragão D, Leslie AGW, Heikal A, Walker JE, Cook GM. Structure of F 1-ATPase from the obligate anaerobe Fusobacterium nucleatum. Open Biol 2019; 9:190066. [PMID: 31238823 PMCID: PMC6597759 DOI: 10.1098/rsob.190066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The crystal structure of the F1-catalytic domain of the adenosine triphosphate (ATP) synthase has been determined from the pathogenic anaerobic bacterium Fusobacterium nucleatum. The enzyme can hydrolyse ATP but is partially inhibited. The structure is similar to those of the F1-ATPases from Caldalkalibacillus thermarum, which is more strongly inhibited in ATP hydrolysis, and in Mycobacterium smegmatis, which has a very low ATP hydrolytic activity. The βE-subunits in all three enzymes are in the conventional ‘open’ state, and in the case of C. thermarum and M. smegmatis, they are occupied by an ADP and phosphate (or sulfate), but in F. nucleatum, the occupancy by ADP appears to be partial. It is likely that the hydrolytic activity of the F. nucleatum enzyme is regulated by the concentration of ADP, as in mitochondria.
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Affiliation(s)
- Jessica Petri
- 1 Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago , Dunedin 9054 , New Zealand
| | - Yoshio Nakatani
- 1 Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago , Dunedin 9054 , New Zealand.,2 Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland , Private Bag 92019, Auckland 1042 , New Zealand
| | - Martin G Montgomery
- 3 Medical Research Council Mitochondrial Biology Unit , Cambridge Biomedical Campus, Cambridge CB2 0XY , UK
| | - Scott A Ferguson
- 1 Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago , Dunedin 9054 , New Zealand
| | - David Aragão
- 4 Australian Synchrotron , 800 Blackburn Road, Clayton, Victoria 3168 , Australia
| | - Andrew G W Leslie
- 5 Medical Research Council Laboratory of Molecular Biology , Cambridge Biomedical Campus, Cambridge CB2 0QH , UK
| | - Adam Heikal
- 1 Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago , Dunedin 9054 , New Zealand.,2 Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland , Private Bag 92019, Auckland 1042 , New Zealand
| | - John E Walker
- 3 Medical Research Council Mitochondrial Biology Unit , Cambridge Biomedical Campus, Cambridge CB2 0XY , UK
| | - Gregory M Cook
- 1 Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago , Dunedin 9054 , New Zealand.,2 Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland , Private Bag 92019, Auckland 1042 , New Zealand
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29
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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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30
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Turbine enzyme's structure in the crosshairs to target tuberculosis. Proc Natl Acad Sci U S A 2019; 116:3956-3958. [PMID: 30782825 DOI: 10.1073/pnas.1900798116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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31
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The structure of the catalytic domain of the ATP synthase from Mycobacterium smegmatis is a target for developing antitubercular drugs. Proc Natl Acad Sci U S A 2019; 116:4206-4211. [PMID: 30683723 DOI: 10.1073/pnas.1817615116] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The crystal structure of the F1-catalytic domain of the adenosine triphosphate (ATP) synthase has been determined from Mycobacterium smegmatis which hydrolyzes ATP very poorly. The structure of the α3β3-component of the catalytic domain is similar to those in active F1-ATPases in Escherichia coli and Geobacillus stearothermophilus However, its ε-subunit differs from those in these two active bacterial F1-ATPases as an ATP molecule is not bound to the two α-helices forming its C-terminal domain, probably because they are shorter than those in active enzymes and they lack an amino acid that contributes to the ATP binding site in active enzymes. In E. coli and G. stearothermophilus, the α-helices adopt an "up" state where the α-helices enter the α3β3-domain and prevent the rotor from turning. The mycobacterial F1-ATPase is most similar to the F1-ATPase from Caldalkalibacillus thermarum, which also hydrolyzes ATP poorly. The βE-subunits in both enzymes are in the usual "open" conformation but appear to be occupied uniquely by the combination of an adenosine 5'-diphosphate molecule with no magnesium ion plus phosphate. This occupation is consistent with the finding that their rotors have been arrested at the same point in their rotary catalytic cycles. These bound hydrolytic products are probably the basis of the inhibition of ATP hydrolysis. It can be envisaged that specific as yet unidentified small molecules might bind to the F1 domain in Mycobacterium tuberculosis, prevent ATP synthesis, and inhibit the growth of the pathogen.
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Bogdanović N, Sundararaman L, Kamariah N, Tyagi A, Bhushan S, Ragunathan P, Shin J, Dick T, Grüber G. Structure and function of Mycobacterium-specific components of F-ATP synthase subunits α and ε. J Struct Biol 2018; 204:420-434. [PMID: 30342092 DOI: 10.1016/j.jsb.2018.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/08/2018] [Accepted: 10/16/2018] [Indexed: 01/21/2023]
Abstract
The Mycobacterium tuberculosis (Mtb) F1FO-ATP synthase (α3:β3:γ:δ:ε:a:b:b':c9) is an essential enzyme that supplies energy for both the aerobic growing and the hypoxic dormant stage of the mycobacterial life cycle. Employing the heterologous F-ATP synthase model system αchi3:β3:γ we showed previously, that transfer of the C-terminal domain (CTD) of Mtb subunit α (Mtα514-549) to a standard F-ATP synthase α subunit suppresses ATPase activity. Here we determined the 3D reconstruction from electron micrographs of the αchi3:β3:γ complex reconstituted with the Mtb subunit ε (Mtε), which has been shown to crosstalk with the CTD of Mtα. Together with the first solution shape of Mtb subunit α (Mtα), derived from solution X-ray scattering, the structural data visualize the extended C-terminal stretch of the mycobacterial subunit α. In addition, Mtε mutants MtεR62L, MtεE87A, Mtε6-121, and Mtε1-120, reconstituted with αchi3:β3:γ provided insight into their role in coupling and in trapping inhibiting MgADP. NMR solution studies of MtεE87A gave insights into how this residue contributes to stability and crosstalk between the N-terminal domain (NTD) and the CTD of Mtε. Analyses of the N-terminal mutant Mtε6-121 highlight the differences of the NTD of mycobacterial subunit ε to the well described Geobacillus stearothermophilus or Escherichia coli counterparts. These data are discussed in context of a crosstalk between the very N-terminal amino acids of Mtε and the loop region of one c subunit of the c-ring turbine for coupling of proton-translocation and ATP synthesis activity.
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Affiliation(s)
- Nebojša Bogdanović
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Lavanya Sundararaman
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Neelagandan Kamariah
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Anu Tyagi
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Shashi Bhushan
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Republic of Singapore
| | - Priya Ragunathan
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Joon Shin
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Thomas Dick
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599, Republic of Singapore; Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, 225 Warren Street, Newark, NJ 07103, USA
| | - Gerhard Grüber
- Nanyang Technological University, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
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Zarco-Zavala M, Mendoza-Hoffmann F, García-Trejo JJ. Unidirectional regulation of the F 1F O-ATP synthase nanomotor by the ζ pawl-ratchet inhibitor protein of Paracoccus denitrificans and related α-proteobacteria. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2018; 1859:762-774. [PMID: 29886048 DOI: 10.1016/j.bbabio.2018.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 05/28/2018] [Accepted: 06/05/2018] [Indexed: 12/20/2022]
Abstract
The ATP synthase is a reversible nanomotor that gyrates its central rotor clockwise (CW) to synthesize ATP and in counter clockwise (CCW) direction to hydrolyse it. In bacteria and mitochondria, two natural inhibitor proteins, namely the ε and IF1 subunits, prevent the wasteful CCW F1FO-ATPase activity by blocking γ rotation at the αDP/βDP/γ interface of the F1 portion. In Paracoccus denitrificans and related α-proteobacteria, we discovered a different natural F1-ATPase inhibitor named ζ. Here we revise the functional and structural data showing that this novel ζ subunit, although being different to ε and IF1, it also binds to the αDP/βDP/γ interface of the F1 of P. denitrificans. ζ shifts its N-terminal inhibitory domain from an intrinsically disordered protein region (IDPr) to an α-helix when inserted in the αDP/βDP/γ interface. We showed for the first time the key role of a natural ATP synthase inhibitor by the distinctive phenotype of a Δζ knockout mutant in P. denitrificans. ζ blocks exclusively the CCW F1FO-ATPase rotation without affecting the CW-F1FO-ATP synthase turnover, confirming that ζ is important for respiratory bacterial growth by working as a unidirectional pawl-ratchet PdF1FO-ATPase inhibitor, thus preventing the wasteful consumption of cellular ATP. In summary, ζ is a useful model that mimics mitochondrial IF1 but in α-proteobacteria. The structural, functional, and endosymbiotic evolutionary implications of this ζ inhibitor are discussed to shed light on the natural control mechanisms of the three natural inhibitor proteins (ε, ζ, and IF1) of this unique ATP synthase nanomotor, essential for life.
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Affiliation(s)
- Mariel Zarco-Zavala
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Delegación Coyoacán, Ciudad de México (CDMX), CP 04510, Mexico; Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Francisco Mendoza-Hoffmann
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Delegación Coyoacán, Ciudad de México (CDMX), CP 04510, Mexico
| | - José J García-Trejo
- Departamento de Biología, Facultad de Química, Ciudad Universitaria, Universidad Nacional Autónoma de México (U.N.A.M.), Delegación Coyoacán, Ciudad de México (CDMX), CP 04510, Mexico.
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34
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Sielaff H, Duncan TM, Börsch M. The regulatory subunit ε in Escherichia coli F OF 1-ATP synthase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:775-788. [PMID: 29932911 DOI: 10.1016/j.bbabio.2018.06.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/13/2018] [Accepted: 06/14/2018] [Indexed: 11/16/2022]
Abstract
F-type ATP synthases are extraordinary multisubunit proteins that operate as nanomotors. The Escherichia coli (E. coli) enzyme uses the proton motive force (pmf) across the bacterial plasma membrane to drive rotation of the central rotor subunits within a stator subunit complex. Through this mechanical rotation, the rotor coordinates three nucleotide binding sites that sequentially catalyze the synthesis of ATP. Moreover, the enzyme can hydrolyze ATP to turn the rotor in the opposite direction and generate pmf. The direction of net catalysis, i.e. synthesis or hydrolysis of ATP, depends on the cell's bioenergetic conditions. Different control mechanisms have been found for ATP synthases in mitochondria, chloroplasts and bacteria. This review discusses the auto-inhibitory behavior of subunit ε found in FOF1-ATP synthases of many bacteria. We focus on E. coli FOF1-ATP synthase, with insights into the regulatory mechanism of subunit ε arising from structural and biochemical studies complemented by single-molecule microscopy experiments.
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Affiliation(s)
- Hendrik Sielaff
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, Jena, Germany
| | - Thomas M Duncan
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Michael Börsch
- Single-Molecule Microscopy Group, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
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