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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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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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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: 16] [Impact Index Per Article: 3.2] [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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