1
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Kamsri B, Kamsri P, Punkvang A, Chimprasit A, Saparpakorn P, Hannongbua S, Spencer J, Oliveira ASF, Mulholland AJ, Pungpo P. Signal Propagation in the ATPase Domain of Mycobacterium tuberculosis DNA Gyrase from Dynamical-Nonequilibrium Molecular Dynamics Simulations. Biochemistry 2024; 63:1493-1504. [PMID: 38742407 PMCID: PMC11154950 DOI: 10.1021/acs.biochem.4c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/26/2024] [Accepted: 05/01/2024] [Indexed: 05/16/2024]
Abstract
DNA gyrases catalyze negative supercoiling of DNA, are essential for bacterial DNA replication, transcription, and recombination, and are important antibacterial targets in multiple pathogens, including Mycobacterium tuberculosis, which in 2021 caused >1.5 million deaths worldwide. DNA gyrase is a tetrameric (A2B2) protein formed from two subunit types: gyrase A (GyrA) carries the breakage-reunion active site, whereas gyrase B (GyrB) catalyzes ATP hydrolysis required for energy transduction and DNA translocation. The GyrB ATPase domains dimerize in the presence of ATP to trap the translocated DNA (T-DNA) segment as a first step in strand passage, for which hydrolysis of one of the two ATPs and release of the resulting inorganic phosphate is rate-limiting. Here, dynamical-nonequilibrium molecular dynamics (D-NEMD) simulations of the dimeric 43 kDa N-terminal fragment of M. tuberculosis GyrB show how events at the ATPase site (dissociation/hydrolysis of bound nucleotides) are propagated through communication pathways to other functionally important regions of the GyrB ATPase domain. Specifically, our simulations identify two distinct pathways that respectively connect the GyrB ATPase site to the corynebacteria-specific C-loop, thought to interact with GyrA prior to DNA capture, and to the C-terminus of the GyrB transduction domain, which in turn contacts the C-terminal GyrB topoisomerase-primase (TOPRIM) domain responsible for interactions with GyrA and the centrally bound G-segment DNA. The connection between the ATPase site and the C-loop of dimeric GyrB is consistent with the unusual properties of M. tuberculosis DNA gyrase relative to those from other bacterial species.
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Affiliation(s)
- Bundit Kamsri
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry,
Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
| | - Pharit Kamsri
- Division
of Chemistry, Faculty of Science, Nakhon
Phanom University, Nakhon
Phanom 48000, Thailand
| | - Auradee Punkvang
- Division
of Chemistry, Faculty of Science, Nakhon
Phanom University, Nakhon
Phanom 48000, Thailand
| | - Aunlika Chimprasit
- Department
of Chemistry, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
| | | | - Supa Hannongbua
- Department
of Chemistry, Faculty of Science, Kasetsart
University, Bangkok 10900, Thailand
| | - James Spencer
- School
of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, U.K.
| | - A. Sofia F. Oliveira
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Adrian J. Mulholland
- Centre
for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Pornpan Pungpo
- Department
of Chemistry and Center of Excellence for Innovation in Chemistry,
Faculty of Science, Ubon Ratchathani University, Ubon Ratchathani 34190, Thailand
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2
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Castelli M, Marchetti F, Osuna S, F. Oliveira AS, Mulholland AJ, Serapian SA, Colombo G. Decrypting Allostery in Membrane-Bound K-Ras4B Using Complementary In Silico Approaches Based on Unbiased Molecular Dynamics Simulations. J Am Chem Soc 2024; 146:901-919. [PMID: 38116743 PMCID: PMC10785808 DOI: 10.1021/jacs.3c11396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/21/2023]
Abstract
Protein functions are dynamically regulated by allostery, which enables conformational communication even between faraway residues, and expresses itself in many forms, akin to different "languages": allosteric control pathways predominating in an unperturbed protein are often unintuitively reshaped whenever biochemical perturbations arise (e.g., mutations). To accurately model allostery, unbiased molecular dynamics (MD) simulations require integration with a reliable method able to, e.g., detect incipient allosteric changes or likely perturbation pathways; this is because allostery can operate at longer time scales than those accessible by plain MD. Such methods are typically applied singularly, but we here argue their joint application─as a "multilingual" approach─could work significantly better. We successfully prove this through unbiased MD simulations (∼100 μs) of the widely studied, allosterically active oncotarget K-Ras4B, solvated and embedded in a phospholipid membrane, from which we decrypt allostery using four showcase "languages": Distance Fluctuation analysis and the Shortest Path Map capture allosteric hotspots at equilibrium; Anisotropic Thermal Diffusion and Dynamical Non-Equilibrium MD simulations assess perturbations upon, respectively, either superheating or hydrolyzing the GTP that oncogenically activates K-Ras4B. Chosen "languages" work synergistically, providing an articulate, mutually coherent, experimentally consistent picture of K-Ras4B allostery, whereby distinct traits emerge at equilibrium and upon GTP cleavage. At equilibrium, combined evidence confirms prominent allosteric communication from the membrane-embedded hypervariable region, through a hub comprising helix α5 and sheet β5, and up to the active site, encompassing allosteric "switches" I and II (marginally), and two proposed pockets. Upon GTP cleavage, allosteric perturbations mostly accumulate on the switches and documented interfaces.
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Affiliation(s)
- Matteo Castelli
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
| | - Filippo Marchetti
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
- INSTM, via G. Giusti 9, 50121 Florence, Italy
- E4
Computer Engineering, via Martiri delle libertà 66, 42019 Scandiano (RE), Italy
| | - Sílvia Osuna
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Girona, Catalonia E-17071, Spain
- ICREA, Barcelona, Catalonia E-08010, Spain
| | - A. Sofia F. Oliveira
- Centre for
Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Adrian J. Mulholland
- Centre for
Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K.
| | - Stefano A. Serapian
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
| | - Giorgio Colombo
- Department
of Chemistry, University of Pavia, viale T. Taramelli 12, 27100 Pavia, Italy
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3
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Lacabanne D, Wiegand T, Di Cesare M, Orelle C, Ernst M, Jault JM, Meier BH, Böckmann A. Solid-State NMR Reveals Asymmetric ATP Hydrolysis in the Multidrug ABC Transporter BmrA. J Am Chem Soc 2022; 144:12431-12442. [PMID: 35776907 PMCID: PMC9284561 DOI: 10.1021/jacs.2c04287] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
The detailed mechanism
of ATP hydrolysis in ATP-binding cassette
(ABC) transporters is still not fully understood. Here, we employed 31P solid-state NMR to probe the conformational changes and
dynamics during the catalytic cycle by locking the multidrug ABC transporter
BmrA in prehydrolytic, transition, and posthydrolytic states, using
a combination of mutants and ATP analogues. The 31P spectra
reveal that ATP binds strongly in the prehydrolytic state to both
ATP-binding sites as inferred from the analysis of the nonhydrolytic
E504A mutant. In the transition state of wild-type BmrA, the symmetry
of the dimer is broken and only a single site is tightly bound to
ADP:Mg2+:vanadate, while the second site is more ‘open’
allowing exchange with the nucleotides in the solvent. In the posthydrolytic
state, weak binding, as characterized by chemical exchange with free
ADP and by asymmetric 31P–31P two-dimensional
(2D) correlation spectra, is observed for both sites. Revisiting the 13C spectra in light of these findings confirms the conformational
nonequivalence of the two nucleotide-binding sites in the transition
state. Our results show that following ATP binding, the symmetry of
the ATP-binding sites of BmrA is lost in the ATP-hydrolysis step,
but is then recovered in the posthydrolytic ADP-bound state.
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Affiliation(s)
| | - Thomas Wiegand
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Margot Di Cesare
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Cédric Orelle
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Matthias Ernst
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Jean-Michel Jault
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
| | - Beat H Meier
- Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland
| | - Anja Böckmann
- Molecular Microbiology and Structural Biochemistry, UMR5086 CNRS/University of Lyon, 7, passage du Vercors, 69367 Lyon, France
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Sofia F. Oliveira A, Shoemark DK, Avila Ibarra A, Davidson AD, Berger I, Schaffitzel C, Mulholland AJ. The fatty acid site is coupled to functional motifs in the SARS-CoV-2 spike protein and modulates spike allosteric behaviour. Comput Struct Biotechnol J 2021; 20:139-147. [PMID: 34934478 PMCID: PMC8670790 DOI: 10.1016/j.csbj.2021.12.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 12/08/2021] [Accepted: 12/08/2021] [Indexed: 12/12/2022] Open
Abstract
The SARS-CoV-2 spike protein is the first contact point between the SARS-CoV-2 virus and host cells and mediates membrane fusion. Recently, a fatty acid binding site was identified in the spike (Toelzer et al. Science 2020). The presence of linoleic acid at this site modulates binding of the spike to the human ACE2 receptor, stabilizing a locked conformation of the protein. Here, dynamical-nonequilibrium molecular dynamics simulations reveal that this fatty acid site is coupled to functionally relevant regions of the spike, some of them far from the fatty acid binding pocket. Removal of a ligand from the fatty acid binding site significantly affects the dynamics of distant, functionally important regions of the spike, including the receptor-binding motif, furin cleavage site and fusion-peptide-adjacent regions. Simulations of the D614G mutant show differences in behaviour between these clinical variants of the spike: the D614G mutant shows a significantly different conformational response for some structural motifs relevant for binding and fusion. The simulations identify structural networks through which changes at the fatty acid binding site are transmitted within the protein. These communication networks significantly involve positions that are prone to mutation, indicating that observed genetic variation in the spike may alter its response to linoleate binding and associated allosteric communication.
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Key Words
- ACE2, angiotensin-converting 2 enzyme
- CD, connector domain
- CH, central helix
- FA, fatty acid
- FP, fusion peptide
- FPPR, fusion-peptide proximal region
- HR1, heptad repeat 1
- LA, Linoleic acid
- MD, Molecular dynamics
- MERS, middle east respiratory syndrome
- NTD, N-terminal domain
- RBD, receptor binding domain
- RBM, receptor-binding motif
- RMB, receptor binding motif
- SARS, severe acute respiratory syndrome
- SARS-CoV-2, severe acute respiratory syndrome 2
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Affiliation(s)
- A. Sofia F. Oliveira
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Deborah K. Shoemark
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - Amaurys Avila Ibarra
- Research Software Engineering, Advanced Computing Research Centre, University of Bristol, Bristol BS1 5QD, UK
| | - Andrew D. Davidson
- School of Cellular and Molecular Medicine, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - Imre Berger
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
- Max Planck Bristol Centre for Minimal Biology, Cantock's Close, Bristol BS8 1TS, UK
| | - Christiane Schaffitzel
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
- School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | - Adrian J. Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
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5
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Abreu B, Cruz C, Oliveira ASF, Soares CM. ATP hydrolysis and nucleotide exit enhance maltose translocation in the MalFGK 2E importer. Sci Rep 2021; 11:10591. [PMID: 34012037 PMCID: PMC8134467 DOI: 10.1038/s41598-021-89556-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 04/27/2021] [Indexed: 02/03/2023] Open
Abstract
ATP binding cassette (ABC) transporters employ ATP hydrolysis to harness substrate translocation across membranes. The Escherichia coli MalFGK2E maltose importer is an example of a type I ABC importer and a model system for this class of ABC transporters. The MalFGK2E importer is responsible for the intake of malto-oligossacharides in E.coli. Despite being extensively studied, little is known about the effect of ATP hydrolysis and nucleotide exit on substrate transport. In this work, we studied this phenomenon using extensive molecular dynamics simulations (MD) along with potential of mean force calculations of maltose transport across the pore, in the pre-hydrolysis, post-hydrolysis and nucleotide-free states. We concluded that ATP hydrolysis and nucleotide exit trigger conformational changes that result in the decrease of energetic barriers to maltose translocation towards the cytoplasm, with a concomitant increase of the energy barrier in the periplasmic side of the pore, contributing for the irreversibility of the process. We also identified key residues that aid in positioning and orientation of maltose, as well as a novel binding pocket for maltose in MalG. Additionally, ATP hydrolysis leads to conformations similar to the nucleotide-free state. This study shows the contribution of ATP hydrolysis and nucleotide exit in the transport cycle, shedding light on ABC type I importer mechanisms.
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Affiliation(s)
- Bárbara Abreu
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Carlos Cruz
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - A. Sofia F. Oliveira
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal ,grid.5337.20000 0004 1936 7603School of Biochemistry and Centre for Computational Chemistry, University of Bristol, Bristol, UK
| | - Cláudio M. Soares
- grid.10772.330000000121511713ITQB NOVA, Instituto de Tecnologia Química E Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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6
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Galdadas I, Qu S, Oliveira ASF, Olehnovics E, Mack AR, Mojica MF, Agarwal PK, Tooke CL, Gervasio FL, Spencer J, Bonomo RA, Mulholland AJ, Haider S. Allosteric communication in class A β-lactamases occurs via cooperative coupling of loop dynamics. eLife 2021; 10:e66567. [PMID: 33755013 PMCID: PMC8060031 DOI: 10.7554/elife.66567] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/19/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding allostery in enzymes and tools to identify it offer promising alternative strategies to inhibitor development. Through a combination of equilibrium and nonequilibrium molecular dynamics simulations, we identify allosteric effects and communication pathways in two prototypical class A β-lactamases, TEM-1 and KPC-2, which are important determinants of antibiotic resistance. The nonequilibrium simulations reveal pathways of communication operating over distances of 30 Å or more. Propagation of the signal occurs through cooperative coupling of loop dynamics. Notably, 50% or more of clinically relevant amino acid substitutions map onto the identified signal transduction pathways. This suggests that clinically important variation may affect, or be driven by, differences in allosteric behavior, providing a mechanism by which amino acid substitutions may affect the relationship between spectrum of activity, catalytic turnover, and potential allosteric behavior in this clinically important enzyme family. Simulations of the type presented here will help in identifying and analyzing such differences.
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Affiliation(s)
- Ioannis Galdadas
- University College London, Department of ChemistryLondonUnited Kingdom
| | - Shen Qu
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
| | - Ana Sofia F Oliveira
- University of Bristol, Centre for Computational Chemistry, School of ChemistryBristolUnited Kingdom
| | - Edgar Olehnovics
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
| | - Andrew R Mack
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Molecular Biology and MicrobiologyClevelandUnited States
| | - Maria F Mojica
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Infectious Diseases, School of MedicineClevelandUnited States
| | - Pratul K Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State UniversityStillwaterUnited States
| | - Catherine L Tooke
- University of Bristol, School of Cellular and Molecular MedicineBristolUnited Kingdom
| | - Francesco Luigi Gervasio
- University College London, Department of ChemistryLondonUnited Kingdom
- University College London, Institute of Structural and Molecular BiologyLondonUnited Kingdom
- University of Geneva, Pharmaceutical SciencesGenevaSwitzerland
| | - James Spencer
- University of Bristol, School of Cellular and Molecular MedicineBristolUnited Kingdom
| | - Robert A Bonomo
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Molecular Biology and MicrobiologyClevelandUnited States
- Case Western Reserve University, Department of Infectious Diseases, School of MedicineClevelandUnited States
- Case Western Reserve University, Department of BiochemistryClevelandUnited States
- Case Western Reserve University, Department of PharmacologyClevelandUnited States
- Case Western Reserve University, Department of Proteomics and BioinformaticsClevelandUnited States
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES)ClevelandUnited States
| | - Adrian J Mulholland
- University of Bristol, Centre for Computational Chemistry, School of ChemistryBristolUnited Kingdom
| | - Shozeb Haider
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
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7
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Oliveira ASF, Ciccotti G, Haider S, Mulholland AJ. Dynamical nonequilibrium molecular dynamics reveals the structural basis for allostery and signal propagation in biomolecular systems. THE EUROPEAN PHYSICAL JOURNAL. B 2021; 94:144. [PMID: 34720710 PMCID: PMC8549953 DOI: 10.1140/epjb/s10051-021-00157-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/05/2021] [Indexed: 05/03/2023]
Abstract
ABSTRACT A dynamical approach to nonequilibrium molecular dynamics (D-NEMD), proposed in the 1970s by Ciccotti et al., is undergoing a renaissance and is having increasing impact in the study of biological macromolecules. This D-NEMD approach, combining MD simulations in stationary (in particular, equilibrium) and nonequilibrium conditions, allows for the determination of the time-dependent structural response of a system using the Kubo-Onsager relation. Besides providing a detailed picture of the system's dynamic structural response to an external perturbation, this approach also has the advantage that the statistical significance of the response can be assessed. The D-NEMD approach has been used recently to identify a general mechanism of inter-domain signal propagation in nicotinic acetylcholine receptors, and allosteric effects in β -lactamase enzymes, for example. It complements equilibrium MD and is a very promising approach to identifying and analysing allosteric effects. Here, we review the D-NEMD approach and its application to biomolecular systems, including transporters, receptors, and enzymes.
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Affiliation(s)
- A. Sofia F. Oliveira
- School of Chemistry, Centre for Computational Chemistry, University of Bristol, Bristol, BS8 1TS UK
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ UK
| | - Giovanni Ciccotti
- Institute for Applied Computing “Mauro Picone” (IAC), CNR, Via dei Taurini 19, 00185 Rome, Italy
- School of Physics, University College of Dublin, UCD-Belfield, Dublin 4, Ireland
- Università di Roma La Sapienza, Ple. A. Moro 5, 00185 Rome, Italy
| | - Shozeb Haider
- School of Pharmacy, University College London, London, WC1N 1AX UK
| | - Adrian J. Mulholland
- School of Chemistry, Centre for Computational Chemistry, University of Bristol, Bristol, BS8 1TS UK
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8
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Dehghani-Ghahnaviyeh S, Kapoor K, Tajkhorshid E. Conformational changes in the nucleotide-binding domains of P-glycoprotein induced by ATP hydrolysis. FEBS Lett 2020; 595:735-749. [PMID: 33159693 DOI: 10.1002/1873-3468.13992] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 10/19/2020] [Accepted: 10/30/2020] [Indexed: 12/16/2022]
Abstract
P-glycoprotein (Pgp) is a member of the ABC transporter superfamily with high physiological importance. Pgp nucleotide-binding domains (NBDs) drive the transport cycle through ATP binding and hydrolysis. We use molecular dynamics simulations to investigate the ATP hydrolysis-induced conformational changes in NBDs. Five systems, including all possible ATP/ADP combinations in the NBDs and the APO system, are simulated. ATP/ADP exchange induces conformational changes mostly within the conserved signature motif of the NBDs, resulting in relative orientational changes in the NBDs. Nucleotide removal leads to additional orientational changes in the NBDs, allowing their dissociation. Furthermore, we capture putative hydrolysis-competent configurations in which the conserved glutamate in the Walker-B motif acts as a catalytic base capturing a water molecule likely initiating ATP hydrolysis.
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Affiliation(s)
- Sepehr Dehghani-Ghahnaviyeh
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL, USA
| | - Karan Kapoor
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL, USA
| | - Emad Tajkhorshid
- Department of Biochemistry, NIH Center for Macromolecular Modeling and Bioinformatics, Center for Biophysics and Quantitative Biology, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, IL, USA
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9
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Characterization of the nucleotide-binding domain NsrF from the BceAB-type ABC-transporter NsrFP from the human pathogen Streptococcus agalactiae. Sci Rep 2020; 10:15208. [PMID: 32938989 PMCID: PMC7494861 DOI: 10.1038/s41598-020-72237-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 08/27/2020] [Indexed: 01/14/2023] Open
Abstract
Treatment of bacterial infections is a great challenge of our era due to the various resistance mechanisms against antibiotics. Antimicrobial peptides are considered to be potential novel compound as antibiotic treatment. However, some bacteria, especially many human pathogens, are inherently resistant to these compounds, due to the expression of BceAB-type ABC transporters. This rather new transporter family is not very well studied. Here, we report the first full characterization of the nucleotide binding domain of a BceAB type transporter from Streptococcus agalactiae, namely SaNsrF of the transporter SaNsrFP, which confers resistance against nisin and gallidermin. We determined the NTP hydrolysis kinetics and used molecular modeling and simulations in combination with small angle X-ray scattering to obtain structural models of the SaNsrF monomer and dimer. The fact that the SaNsrFH202A variant displayed no ATPase activity was rationalized in terms of changes of the structural dynamics of the dimeric interface. Kinetic data show a clear preference for ATP as a substrate, and the prediction of binding modes allowed us to explain this selectivity over other NTPs.
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10
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Multidrug ABC transporters in bacteria. Res Microbiol 2019; 170:381-391. [DOI: 10.1016/j.resmic.2019.06.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 06/12/2019] [Accepted: 06/17/2019] [Indexed: 12/23/2022]
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11
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Abreu B, Lopes EF, Oliveira ASF, Soares CM. F508del disturbs the dynamics of the nucleotide binding domains of CFTR before and after ATP hydrolysis. Proteins 2019; 88:113-126. [PMID: 31298435 DOI: 10.1002/prot.25776] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 06/17/2019] [Accepted: 07/06/2019] [Indexed: 12/20/2022]
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) channel is an ion channel responsible for chloride transport in epithelia and it belongs to the class of ABC transporters. The deletion of phenylalanine 508 (F508del) in CFTR is the most common mutation responsible for cystic fibrosis. Little is known about the effect of the mutation in the isolated nucleotide binding domains (NBDs), on dimer dynamics, ATP hydrolysis and even on nucleotide binding. Using molecular dynamics simulations of the human CFTR NBD dimer, we showed that F508del increases, in the prehydrolysis state, the inter-motif distance in both ATP binding sites (ABP) when ATP is bound. Additionally, a decrease in the number of catalytically competent conformations was observed in the presence of F508del. We used the subtraction technique to study the first 300 ps after ATP hydrolysis in the catalytic competent site and found that the F508del dimer evidences lower conformational changes than the wild type. Using longer simulation times, the magnitude of the conformational changes in both forms increases. Nonetheless, the F508del dimer shows lower C-α RMS values in comparison to the wild-type, on the F508del loop, on the residues surrounding the catalytic site and the portion of NBD2 adjacent to ABP1. These results provide evidence that F508del interferes with the NBD dynamics before and after ATP hydrolysis. These findings shed a new light on the effect of F508del on NBD dynamics and reveal a novel mechanism for the influence of F508del on CFTR.
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Affiliation(s)
- Bárbara Abreu
- Protein Modelling Lab, ITQB-NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Emanuel F Lopes
- Protein Modelling Lab, ITQB-NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
| | - A S F Oliveira
- Protein Modelling Lab, ITQB-NOVA, Universidade Nova de Lisboa, Oeiras, Portugal.,School of Biochemistry & Center for Computational Chemistry, University of Bristol, Bristol, UK
| | - Cláudio M Soares
- Protein Modelling Lab, ITQB-NOVA, Universidade Nova de Lisboa, Oeiras, Portugal
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12
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Oliveira ASF, Shoemark DK, Campello HR, Wonnacott S, Gallagher T, Sessions RB, Mulholland AJ. Identification of the Initial Steps in Signal Transduction in the α4β2 Nicotinic Receptor: Insights from Equilibrium and Nonequilibrium Simulations. Structure 2019; 27:1171-1183.e3. [PMID: 31130483 DOI: 10.1016/j.str.2019.04.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 01/28/2019] [Accepted: 04/10/2019] [Indexed: 02/02/2023]
Abstract
Nicotinic acetylcholine receptors (nAChRs) modulate synaptic transmission in the nervous system. These receptors have emerged as therapeutic targets in drug discovery for treating several conditions, including Alzheimer's disease, pain, and nicotine addiction. In this in silico study, we use a combination of equilibrium and nonequilibrium molecular dynamics simulations to map dynamic and structural changes induced by nicotine in the human α4β2 nAChR. They reveal a striking pattern of communication between the extracellular binding pockets and the transmembrane domains (TMDs) and show the sequence of conformational changes associated with the initial steps in this process. We propose a general mechanism for signal transduction for Cys-loop receptors: the mechanistic steps for communication proceed firstly through loop C in the principal subunit, and are subsequently transmitted, gradually and cumulatively, to loop F of the complementary subunit, and then to the TMDs through the M2-M3 linker.
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Affiliation(s)
- A Sofia F Oliveira
- School of Biochemistry, University of Bristol, Bristol BS8 1DT, UK; Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | | | - Hugo Rego Campello
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | - Susan Wonnacott
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
| | - Timothy Gallagher
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK
| | | | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, UK.
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13
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Sakamoto M, Suzuki H, Yura K. Relationship between conformation shift and disease related variation sites in ATP-binding cassette transporter proteins. Biophys Physicobiol 2019; 16:68-79. [PMID: 30923664 PMCID: PMC6435017 DOI: 10.2142/biophysico.16.0_68] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Accepted: 01/07/2019] [Indexed: 12/13/2022] Open
Abstract
Transport of small molecules across the cell membrane is a crucial biological mechanism for the maintenance of the cell activity. ABC transporter family is a huge group in the transporter membrane proteins and actively transports the substrates using the energy derived from ATP hydrolysis. In humans, there are 48 distinct genes for ABC transporters. A variation of a single amino acid in the amino acid sequence of ABC transporter has been known to be linked with certain disease. The mechanism of the onset of the disease by the variation is, however, still unclear. Recent progress in the method to measure the structures of huge membrane proteins has enabled determination of the 3D structures of ABC transporters and the accumulation of coordinate data of ABC transporter has enabled us to obtain clues for the onset of the disease caused by a single variation of amino acid residue. We compared the structures of ABC transporter in apo and ATP-binding forms and found a possible conformation shift around pivot-like residues in the transmembrane domains. When this conformation change in ABC transporter and the location of pathogenic variation were compared, we found a reasonable match between the two, explaining the onset of the disease by the variation. They likely cause impairment of the pivot-like movement, weakening of ATP binding and weakening of membrane surface interactions. These findings will give a new interpretation of the variations on ABC transporter genes and pave a way to analyse the effect of variation on protein structure and function.
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Affiliation(s)
- Mika Sakamoto
- Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan
| | - Hirofumi Suzuki
- School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-0072, Japan
| | - Kei Yura
- Graduate School of Humanities and Sciences, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan.,School of Advanced Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-0072, Japan.,Center for Simulation Science and Informational Biology, Ochanomizu University, Bunkyo-ku, Tokyo 112-8610, Japan
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14
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Kaur H, Abreu B, Akhmetzyanov D, Lakatos-Karoly A, Soares CM, Prisner T, Glaubitz C. Unexplored Nucleotide Binding Modes for the ABC Exporter MsbA. J Am Chem Soc 2018; 140:14112-14125. [PMID: 30289253 DOI: 10.1021/jacs.8b06739] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The ATP-binding cassette (ABC) transporter MsbA is an ATP-driven lipid-A flippase. It belongs to the ABC protein superfamily whose members are characterized by conserved motifs in their nucleotide binding domains (NBDs), which are responsible for ATP hydrolysis. Recently, it was found that MsbA could catalyze a reverse adenylate kinase (rAK)-like reaction in addition to ATP hydrolysis. Both reactions are connected and mediated by the same conserved NBD domains. Here, the structural foundations underlying the nucleotide binding to MsbA were therefore explored using a concerted approach based on conventional- and DNP-enhanced solid-state NMR, pulsed-EPR, and MD simulations. MsbA reconstituted into lipid bilayers was trapped in various catalytic states corresponding to intermediates of the coupled ATPase-rAK mechanism. The analysis of nucleotide-binding dependent chemical shift changes, and the detection of through-space contacts between bound nucleotides and MsbA within these states provides evidence for an additional nucleotide-binding site in close proximity to the Q-loop and the His-Switch. By replacing Mg2+ with Mn2+ and employing pulsed EPR spectroscopy, evidence is provided that this newly found nucleotide binding site does not interfere with the coordination of the required metal ion. Molecular dynamic (MD) simulations of nucleotide and metal binding required for the coupled ATPase-rAK mechanism have been used to corroborate these experimental findings and provide additional insight into nucleotide location, orientation, and possible binding modes.
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Affiliation(s)
- Hundeep Kaur
- Institute for Biophysical Chemistry & Centre for Biomolecular Magnetic Resonance , Goethe-University Frankfurt , 60438 Frankfurt , Germany
| | - Bárbara Abreu
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , 2780-157 Oeiras , Portugal
| | - Dmitry Akhmetzyanov
- Institute for Physical and Theoretical Chemistry & Centre for Biomolecular Magnetic Resonance , Goethe-University Frankfurt , 60438 Frankfurt , Germany
| | - Andrea Lakatos-Karoly
- Institute for Biophysical Chemistry & Centre for Biomolecular Magnetic Resonance , Goethe-University Frankfurt , 60438 Frankfurt , Germany
| | - Cláudio M Soares
- ITQB NOVA, Instituto de Tecnologia Química e Biológica António Xavier , Universidade Nova de Lisboa , 2780-157 Oeiras , Portugal
| | - Thomas Prisner
- Institute for Physical and Theoretical Chemistry & Centre for Biomolecular Magnetic Resonance , Goethe-University Frankfurt , 60438 Frankfurt , Germany
| | - Clemens Glaubitz
- Institute for Biophysical Chemistry & Centre for Biomolecular Magnetic Resonance , Goethe-University Frankfurt , 60438 Frankfurt , Germany
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15
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Pan X, Zhang Q, Qu S, Huang S, Wang H, Mei H. Allosteric effects of ATP binding on the nucleotide-binding domain of a heterodimeric ATP-binding cassette transporter. Integr Biol (Camb) 2017; 8:1158-1169. [PMID: 27731447 DOI: 10.1039/c6ib00136j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ATP-binding cassette (ABC) exporters mediate vital transport of a variety of molecules across the lipid bilayer in all organisms. To explore the allosteric effect of ATP binding at the asymmetric ATPase sites, molecular dynamics simulations were performed on the nucleotide-binding domains (NBDs) of a heterodimeric exporter TM287/288 in 4 different ATP-bound states. The results showed that ATP bound at the degenerate site can maintain a semi-open conformation of NBD1-NBD2, which may be defective in ATP hydrolysis. By contrast, when bound at the consensus site, ATP can induce an intra-domain rotation of the α-helical subdomain towards the RecA-like subdomain of NBD2 at the degenerate site. The rotation of the α-helical subdomain rearranged the hydrogen bond networks at the NBD1-NBD2 interface, induced a significant conformational change in the D-loop at the degenerate site and inter- and intra-domain communications at both sites, and eventually elicited dimerization of NBD1-NBD2. These findings indicate that the asymmetric ATPase sites of the heterodimeric exporter are structurally and functionally distinct.
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Affiliation(s)
- Xianchao Pan
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400044, China. and College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Qiaoxia Zhang
- Chongqing Research Institute of Chemical Industry, Chongqing 400021, China
| | - Sujun Qu
- College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Shuheng Huang
- College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Huicong Wang
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400044, China. and College of Bioengineering, Chongqing University, Chongqing 400044, China
| | - Hu Mei
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, Chongqing University, Chongqing 400044, China. and College of Bioengineering, Chongqing University, Chongqing 400044, China
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16
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Jones PM, George AM. How Intrinsic Dynamics Mediates the Allosteric Mechanism in the ABC Transporter Nucleotide Binding Domain Dimer. J Chem Theory Comput 2017; 13:1712-1722. [PMID: 28240893 DOI: 10.1021/acs.jctc.6b00839] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A protein's architecture facilitates specific motions-intrinsic dynamic modes-that are employed to effect function. Here we used molecular dynamics (MD) simulations to investigate the dynamics of the MJ0796 ABC transporter nucleotide-binding domain (NBD). ABC transporter NBDs form a rotationally symmetric dimer whereby two equivalent active sites are formed at their interface; in complex with a dimer of transmembrane domains they hydrolyze ATP to energize translocation of substrates across cellular membranes. Our data suggest the ABC NBD's ensemble of functional states can be understood predominately in terms of conformational changes between its major subdomains, occurring along two orthogonal dynamic modes. The data show that ligands and oligomeric interactions modulate the equilibrium conformation of the NBD with respect to these motions, suggesting that allostery is achieved by affecting the energetic profile along these two modes. The observed dynamics and allostery integrate consonantly and logically within a mechanistic framework for the ABC NBD dimer, which is supported by a large body of experimental and theoretical data, providing a higher resolution view of the enzyme's dynamic cycle. Our study shows how valuable mechanistic inferences can be derived from accessible short-time scale MD simulations of an enzyme's substructures.
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Affiliation(s)
- Peter M Jones
- School of Life Sciences, University of Technology Sydney , P.O. Box 123, Broadway, New South Wales 2007, Australia
| | - Anthony M George
- School of Life Sciences, University of Technology Sydney , P.O. Box 123, Broadway, New South Wales 2007, Australia
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17
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Prachayasittikul V, Worachartcheewan A, Toropova AP, Toropov AA, Schaduangrat N, Prachayasittikul V, Nantasenamat C. Large-scale classification of P-glycoprotein inhibitors using SMILES-based descriptors. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2017; 28:1-16. [PMID: 28056566 DOI: 10.1080/1062936x.2016.1264468] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 11/21/2016] [Indexed: 06/06/2023]
Abstract
P-glycoprotein (Pgp) inhibition has been considered as an effective strategy towards combating multidrug-resistant cancers. Owing to the substrate promiscuity of Pgp, the classification of its interacting ligands is not an easy task and is an ongoing issue of debate. Chemical structures can be represented by the simplified molecular input line entry system (SMILES) in the form of linear string of symbols. In this study, the SMILES notations of 2254 Pgp inhibitors including 1341 active, and 913 inactive compounds were used for the construction of a SMILE-based classification model using CORrelation And Logic (CORAL) software. The model provided an acceptable predictive performance as observed from statistical parameters consisting of accuracy, sensitivity and specificity that afforded values greater than 70% and MCC value greater than 0.6 for training, calibration and validation sets. In addition, the CORAL method highlighted chemical features that may contribute to increased and decreased Pgp inhibitory activities. This study highlights the potential of CORAL software for rapid screening of prospective compounds from a large chemical space and provides information that could aid in the design and development of potential Pgp inhibitors.
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Affiliation(s)
- V Prachayasittikul
- a Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
| | - A Worachartcheewan
- a Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
- b Department of Community Medical Technology, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
- c Department of Clinical Chemistry, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
| | - A P Toropova
- d IRCCS , Istituto di Ricerche Farmacologiche Mario Negri , Milano , Italy
| | - A A Toropov
- d IRCCS , Istituto di Ricerche Farmacologiche Mario Negri , Milano , Italy
| | - N Schaduangrat
- a Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
| | - V Prachayasittikul
- e Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
| | - C Nantasenamat
- a Center of Data Mining and Biomedical Informatics, Faculty of Medical Technology , Mahidol University , Bangkok , Thailand
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18
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Pan C, Weng J, Wang W. ATP Hydrolysis Induced Conformational Changes in the Vitamin B12 Transporter BtuCD Revealed by MD Simulations. PLoS One 2016; 11:e0166980. [PMID: 27870912 PMCID: PMC5117765 DOI: 10.1371/journal.pone.0166980] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 11/07/2016] [Indexed: 12/17/2022] Open
Abstract
ATP binding cassette (ABC) transporters utilize the energy of ATP hydrolysis to uni-directionally transport substrates across cell membrane. ATP hydrolysis occurs at the nucleotide-binding domain (NBD) dimer interface of ABC transporters, whereas substrate translocation takes place at the translocation pathway between the transmembrane domains (TMDs), which is more than 30 angstroms away from the NBD dimer interface. This raises the question of how the hydrolysis energy released at NBDs is "transmitted" to trigger the conformational changes at TMDs. Using molecular dynamics (MD) simulations, we studied the post-hydrolysis state of the vitamin B12 importer BtuCD. Totally 3-μs MD trajectories demonstrate a predominantly asymmetric arrangement of the NBD dimer interface, with the ADP-bound site disrupted and the ATP-bound site preserved in most of the trajectories. TMDs response to ATP hydrolysis by separation of the L-loops and opening of the cytoplasmic gate II, indicating that hydrolysis of one ATP could facilitate substrate translocation by opening the cytoplasmic end of translocation pathway. It was also found that motions of the L-loops and the cytoplasmic gate II are coupled with each other through a contiguous interaction network involving a conserved Asn83 on the extended stretch preceding TM3 helix plus the cytoplasmic end of TM2/6/7 helix bundle. These findings entail a TMD-NBD communication mechanism for type II ABC importers.
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Affiliation(s)
- Chao Pan
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University, Shanghai, P. R. China
| | - Jingwei Weng
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University, Shanghai, P. R. China
| | - Wenning Wang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, and Institutes of Biomedical Sciences, Fudan University, Shanghai, P. R. China
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19
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Conformational Motions and Functionally Key Residues for Vitamin B12 Transporter BtuCD-BtuF Revealed by Elastic Network Model with a Function-Related Internal Coordinate. Int J Mol Sci 2015; 16:17933-51. [PMID: 26247943 PMCID: PMC4581229 DOI: 10.3390/ijms160817933] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/10/2015] [Accepted: 07/20/2015] [Indexed: 11/17/2022] Open
Abstract
BtuCD-BtuF from Escherichia coli is a binding protein-dependent adenosine triphosphate (ATP)-binding cassette (ABC) transporter system that uses the energy of ATP hydrolysis to transmit vitamin B12 across cellular membranes. Experimental studies have showed that during the transport cycle, the transporter undergoes conformational transitions between the "inward-facing" and "outward-facing" states, which results in the open-closed motions of the cytoplasmic gate of the transport channel. The opening-closing of the channel gate play critical roles for the function of the transporter, which enables the substrate vitamin B12 to be translocated into the cell. In the present work, the extent of opening of the cytoplasmic gate was chosen as a function-related internal coordinate. Then the mean-square fluctuation of the internal coordinate, as well as the cross-correlation between the displacement of the internal coordinate and the movement of each residue in the protein, were calculated based on the normal mode analysis of the elastic network model to analyze the function-related motions encoded in the structure of the system. In addition, the key residues important for the functional motions of the transporter were predicted by using a perturbation method. In order to facilitate the calculations, the internal coordinate was introduced as one of the axes of the coordinate space and the conventional Cartesian coordinate space was transformed into the internal/Cartesian space with linear approximation. All the calculations were carried out in this internal/Cartesian space. Our method can successfully identify the functional motions and key residues for the transporter BtuCD-BtuF, which are well consistent with the experimental observations.
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20
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Ferreira RJ, Ferreira MJU, dos Santos DJVA. Do adsorbed drugs onto P-glycoprotein influence its efflux capability? Phys Chem Chem Phys 2015; 17:22023-34. [PMID: 26235302 DOI: 10.1039/c5cp03216d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The membrane biophysical aspects by which multidrug resistance (MDR) relate to the ABC transporter function still remain largely unknown. Notwithstanding the central role that efflux pumps like P-glycoprotein have in MDR onset, experimental studies classified additionally the lipid micro-environment where P-gp is inserted as a determinant for the increased efflux capability demonstrated in MDR cell lines. Recently, a nonlinear model for drug-membrane interactions showed that, upon drug adsorption, long-range mechanical alterations are predicted to affect the P-gp ATPase function at external drug concentrations of ∼10-100 μM. However, our results also show that drug adsorption may also occur at P-gp nucleotide-binding domains where conformational changes drive the efflux cycle. Thus, we assessed the effect of drug adsorption to both protein-water and lipid-water interfaces by means of molecular dynamics simulations. The results show that free energies of adsorption are lower for modulators in both lipid/water and protein/water interfaces. Important differences in drug-protein interactions, protein dynamics and membrane biophysical characteristics were observed between the different classes. Therefore, we hypothesize that drug adsorption to the protein and lipid-water interface accounts for a complex network of events that affect the ability of transporters to efflux drugs.
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Affiliation(s)
- Ricardo J Ferreira
- Research Institute for Medicines (iMed.Ulisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa, Portugal.
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21
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Corradi V, Vergani P, Tieleman DP. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR): CLOSED AND OPEN STATE CHANNEL MODELS. J Biol Chem 2015; 290:22891-906. [PMID: 26229102 PMCID: PMC4645605 DOI: 10.1074/jbc.m115.665125] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Indexed: 01/06/2023] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-binding cassette (ABC) transporter superfamily. CFTR controls the flow of anions through the apical membrane of epithelia. Dysfunctional CFTR causes the common lethal genetic disease cystic fibrosis. Transitions between open and closed states of CFTR are regulated by ATP binding and hydrolysis on the cytosolic nucleotide binding domains, which are coupled with the transmembrane (TM) domains forming the pathway for anion permeation. Lack of structural data hampers a global understanding of CFTR and thus the development of "rational" approaches directly targeting defective CFTR. In this work, we explored possible conformational states of the CFTR gating cycle by means of homology modeling. As templates, we used structures of homologous ABC transporters, namely TM(287-288), ABC-B10, McjD, and Sav1866. In the light of published experimental results, structural analysis of the transmembrane cavity suggests that the TM(287-288)-based CFTR model could correspond to a commonly occupied closed state, whereas the McjD-based model could represent an open state. The models capture the important role played by Phe-337 as a filter/gating residue and provide structural information on the conformational transition from closed to open channel.
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Affiliation(s)
- Valentina Corradi
- From the Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
| | - Paola Vergani
- Research Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - D Peter Tieleman
- From the Department of Biological Sciences and Centre for Molecular Simulation, University of Calgary, Calgary, Alberta T2N 1N4, Canada and
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22
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Jones PM, George AM. The Nucleotide-Free State of the Multidrug Resistance ABC Transporter LmrA: Sulfhydryl Cross-Linking Supports a Constant Contact, Head-to-Tail Configuration of the Nucleotide-Binding Domains. PLoS One 2015; 10:e0131505. [PMID: 26120849 PMCID: PMC4485892 DOI: 10.1371/journal.pone.0131505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/03/2015] [Indexed: 12/12/2022] Open
Abstract
ABC transporters are integral membrane pumps that are responsible for the import or export of a diverse range of molecules across cell membranes. ABC transporters have been implicated in many phenomena of medical importance, including cystic fibrosis and multidrug resistance in humans. The molecular architecture of ABC transporters comprises two transmembrane domains and two ATP-binding cassettes, or nucleotide-binding domains (NBDs), which are highly conserved and contain motifs that are crucial to ATP binding and hydrolysis. Despite the improved clarity of recent structural, biophysical, and biochemical data, the seemingly simple process of ATP binding and hydrolysis remains controversial, with a major unresolved issue being whether the NBD protomers separate during the catalytic cycle. Here chemical cross-linking data is presented for the bacterial ABC multidrug resistance (MDR) transporter LmrA. These indicate that in the absence of nucleotide or substrate, the NBDs come into contact to a significant extent, even at 4°C, where ATPase activity is abrogated. The data are clearly not in accord with an inward-closed conformation akin to that observed in a crystal structure of V. cholerae MsbA. Rather, they suggest a head-to-tail configuration ‘sandwich’ dimer similar to that observed in crystal structures of nucleotide-bound ABC NBDs. We argue the data are more readily reconciled with the notion that the NBDs are in proximity while undergoing intra-domain motions, than with an NBD ‘Switch’ mechanism in which the NBD monomers separate in between ATP hydrolysis cycles.
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Affiliation(s)
- Peter M Jones
- School of Life Sciences, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia
| | - Anthony M George
- School of Life Sciences, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia
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23
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Subramanian N, Condic-Jurkic K, Mark AE, O'Mara ML. Identification of Possible Binding Sites for Morphine and Nicardipine on the Multidrug Transporter P-Glycoprotein Using Umbrella Sampling Techniques. J Chem Inf Model 2015; 55:1202-17. [PMID: 25938863 DOI: 10.1021/ci5007382] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The multidrug transporter P-glycoprotein (P-gp) is central to the development of multidrug resistance in cancer. While residues essential for transport and binding have been identified, the location, composition, and specificity of potential drug binding sites are uncertain. Here molecular dynamics simulations are used to calculate the free energy profile for the binding of morphine and nicardipine to P-gp. We show that morphine and nicardipine primarily interact with key residues implicated in binding and transport from mutational studies, binding at different but overlapping sites within the transmembrane pore. Their permeation pathways were distinct but involved overlapping sets of residues. The results indicate that the binding location and permeation pathways of morphine and nicardipine are not well separated and cannot be considered as unique. This has important implications for our understanding of substrate uptake and transport by P-gp. Our results are independent of the choice of starting structure and consistent with a range of experimental studies.
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Affiliation(s)
- Nandhitha Subramanian
- †School of Chemistry and Molecular Biosciences, §The Institute for Molecular Biosciences, and ‡School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Karmen Condic-Jurkic
- †School of Chemistry and Molecular Biosciences, §The Institute for Molecular Biosciences, and ‡School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Alan E Mark
- †School of Chemistry and Molecular Biosciences, §The Institute for Molecular Biosciences, and ‡School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
| | - Megan L O'Mara
- †School of Chemistry and Molecular Biosciences, §The Institute for Molecular Biosciences, and ‡School of Mathematics and Physics, University of Queensland, Brisbane, QLD 4072, Australia
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24
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Prajapati R, Sangamwar AT. Translocation mechanism of P-glycoprotein and conformational changes occurring at drug-binding site: Insights from multi-targeted molecular dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2882-98. [DOI: 10.1016/j.bbamem.2014.07.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 07/03/2014] [Accepted: 07/08/2014] [Indexed: 11/29/2022]
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25
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Ferreira RJ, Ferreira MJU, dos Santos DJVA. Reversing cancer multidrug resistance: insights into the efflux by ABC transports fromin silicostudies. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2014. [DOI: 10.1002/wcms.1196] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Ricardo J. Ferreira
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia; Universidade de Lisboa; Lisboa Portugal
| | - Maria-José U. Ferreira
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia; Universidade de Lisboa; Lisboa Portugal
| | - Daniel J. V. A. dos Santos
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia; Universidade de Lisboa; Lisboa Portugal
- REQUIMTE, Department of Chemistry & Biochemistry, Faculty of Sciences; University of Porto; Porto Portugal
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26
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Abstract
Potassium is a macronutrient that is crucial for healthy plant growth. Potassium availability, however, is often limited in agricultural fields and thus crop yields and quality are reduced. Therefore, improving the efficiency of potassium uptake and transport, as well as its utilization, in plants is important for agricultural sustainability. This review summarizes the current knowledge on the molecular mechanisms involved in potassium uptake and transport in plants, and the molecular response of plants to different levels of potassium availability. Based on this information, four strategies for improving potassium use efficiency in plants are proposed; 1) increased root volume, 2) increasing efficiency of potassium uptake from the soil and translocation in planta, 3) increasing mobility of potassium in soil, and 4) molecular breeding new varieties with greater potassium efficiency through marker assisted selection which will require identification and utilization of potassium associated quantitative trait loci.
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Affiliation(s)
- Ryoung Shin
- RIKEN Center for Sustainable Resource Science, Yokohama 230-0045,
Japan
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27
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Dawson JE, Farber PJ, Forman-Kay JD. Allosteric coupling between the intracellular coupling helix 4 and regulatory sites of the first nucleotide-binding domain of CFTR. PLoS One 2013; 8:e74347. [PMID: 24058550 PMCID: PMC3776845 DOI: 10.1371/journal.pone.0074347] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 08/01/2013] [Indexed: 12/25/2022] Open
Abstract
Cystic fibrosis is caused by mutations in CFTR (cystic fibrosis transmembrane conductance regulator), leading to folding and processing defects and to chloride channel gating misfunction. CFTR is regulated by ATP binding to its cytoplasmic nucleotide-binding domains, NBD1 and NBD2, and by phosphorylation of the NBD1 regulatory insert (RI) and the regulatory extension (RE)/R region. These regulatory effects are transmitted to the rest of the channel via NBD interactions with intracellular domain coupling helices (CL), particularly CL4. Using a sensitive method for detecting inter-residue correlations between chemical shift changes in NMR spectra, an allosteric network was revealed within NBD1, with a construct lacking RI. The CL4-binding site couples to the RI-deletion site and the C-terminal residues of NBD1 that precede the R region in full-length CFTR. Titration of CL4 peptide into NBD1 perturbs the conformational ensemble in these sites with similar titration patterns observed in F508del, the major CF-causing mutant, and in suppressor mutants F494N, V510D and Q637R NBD1, as well as in a CL4-NBD1 fusion construct. Reciprocally, the C-terminal mutation, Q637R, perturbs dynamics in these three sites. This allosteric network suggests a mechanism synthesizing diverse regulatory NBD1 interactions and provides biophysical evidence for the allosteric coupling required for CFTR function.
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Affiliation(s)
- Jennifer E. Dawson
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Patrick J. Farber
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Julie D. Forman-Kay
- Molecular Structure and Function Program, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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28
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Volkers G, Damas JM, Palm GJ, Panjikar S, Soares CM, Hinrichs W. Putative dioxygen-binding sites and recognition of tigecycline and minocycline in the tetracycline-degrading monooxygenase TetX. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2013; 69:1758-67. [PMID: 23999299 DOI: 10.1107/s0907444913013802] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 05/19/2013] [Indexed: 12/28/2022]
Abstract
Expression of the aromatic hydroxylase TetX under aerobic conditions confers bacterial resistance against tetracycline antibiotics. Hydroxylation inactivates and degrades tetracyclines, preventing inhibition of the prokaryotic ribosome. X-ray crystal structure analyses of TetX in complex with the second-generation and third-generation tetracyclines minocycline and tigecycline at 2.18 and 2.30 Å resolution, respectively, explain why both clinically potent antibiotics are suitable substrates. Both tetracyclines bind in a large tunnel-shaped active site in close contact to the cofactor FAD, pre-oriented for regioselective hydroxylation to 11a-hydroxytetracyclines. The characteristic bulky 9-tert-butylglycylamido substituent of tigecycline is solvent-exposed and does not interfere with TetX binding. In the TetX-minocycline complex a second binding site for a minocycline dimer is observed close to the active-site entrance. The pocket is formed by the crystal packing arrangement on the surface of two neighbouring TetX monomers. Crystal structure analysis at 2.73 Å resolution of xenon-pressurized TetX identified two adjacent Xe-binding sites. These putative dioxygen-binding cavities are located in the substrate-binding domain next to the active site. Molecular-dynamics simulations were performed in order to characterize dioxygen-diffusion pathways to FADH2 at the active site.
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Affiliation(s)
- Gesa Volkers
- Department of Molecular Structural Biology, Institute for Biochemistry, University of Greifswald, Felix-Hausdorff-Strasse 4, Greifswald, Germany
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29
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Ma J, Biggin PC. Substrate versus inhibitor dynamics of P-glycoprotein. Proteins 2013; 81:1653-68. [PMID: 23670856 DOI: 10.1002/prot.24324] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 03/24/2013] [Accepted: 04/19/2013] [Indexed: 12/20/2022]
Abstract
By far the most studied multidrug resistance protein is P-glycoprotein. Despite recent structural data, key questions about its function remain. P-glycoprotein (P-gp) is flexible and undergoes large conformational changes as part of its function and in this respect, details not only of the export cycle, but also the recognition stage are currently lacking. Given the flexibility, molecular dynamics (MD) simulations provide an ideal tool to examine this aspect in detail. We have performed MD simulations to examine the behaviour of P-gp. In agreement with previous reports, we found that P-gp undergoes large conformational changes which tended to result in the nucleotide-binding domains coming closer together. In all simulations, the approach of the NBDs was asymmetrical in agreement with previous observations for other ABC transporter proteins. To validate the simulations, we make extensive comparison to previous cross-linking data. Our results show very good agreement with the available data. We then went on to compare the influence of inhibitor compounds bound with simulations of a substrate (daunorubicin) bound. Our results suggest that inhibitors may work by keeping the NBDs apart, thus preventing ATP-hydrolysis. On the other hand, repeat simulations of daunorubicin (substrate) in one particular binding pose suggest that the approach of the NBDs is not impaired and that the structure would be still be competent to perform ATP hydrolysis, thus providing a model for inhibition or substrate transport. Finally we compare the latter to earlier QSAR data to provide a model for the first part of substrate transport within P-gp.
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Affiliation(s)
- Jerome Ma
- Department of Biochemistry, Structural Bioinformatics and Computational Biochemistry, University of Oxford, Oxford, OX1 3QU, United Kingdom
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30
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In silico model for P-glycoprotein substrate prediction: insights from molecular dynamics and in vitro studies. J Comput Aided Mol Des 2013; 27:347-63. [DOI: 10.1007/s10822-013-9650-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 04/16/2013] [Indexed: 11/25/2022]
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31
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Shaikh S, Li J, Enkavi G, Wen PC, Huang Z, Tajkhorshid E. Visualizing functional motions of membrane transporters with molecular dynamics simulations. Biochemistry 2013; 52:569-87. [PMID: 23298176 PMCID: PMC3560430 DOI: 10.1021/bi301086x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 12/21/2012] [Indexed: 01/08/2023]
Abstract
Computational modeling and molecular simulation techniques have become an integral part of modern molecular research. Various areas of molecular sciences continue to benefit from, indeed rely on, the unparalleled spatial and temporal resolutions offered by these technologies, to provide a more complete picture of the molecular problems at hand. Because of the continuous development of more efficient algorithms harvesting ever-expanding computational resources, and the emergence of more advanced and novel theories and methodologies, the scope of computational studies has expanded significantly over the past decade, now including much larger molecular systems and far more complex molecular phenomena. Among the various computer modeling techniques, the application of molecular dynamics (MD) simulation and related techniques has particularly drawn attention in biomolecular research, because of the ability of the method to describe the dynamical nature of the molecular systems and thereby to provide a more realistic representation, which is often needed for understanding fundamental molecular properties. The method has proven to be remarkably successful in capturing molecular events and structural transitions highly relevant to the function and/or physicochemical properties of biomolecular systems. Herein, after a brief introduction to the method of MD, we use a number of membrane transport proteins studied in our laboratory as examples to showcase the scope and applicability of the method and its power in characterizing molecular motions of various magnitudes and time scales that are involved in the function of this important class of membrane proteins.
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Affiliation(s)
- Saher
A. Shaikh
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Jing Li
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Giray Enkavi
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Po-Chao Wen
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Zhijian Huang
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
| | - Emad Tajkhorshid
- Department of Biochemistry, Beckman Institute for Advanced
Science and Technology, and Center for Biophysics and Computational
Biology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
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32
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Kolaczkowski M, Sroda-Pomianek K, Kolaczkowska A, Michalak K. A conserved interdomain communication pathway of pseudosymmetrically distributed residues affects substrate specificity of the fungal multidrug transporter Cdr1p. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:479-90. [PMID: 23122779 DOI: 10.1016/j.bbamem.2012.10.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 09/19/2012] [Accepted: 10/21/2012] [Indexed: 11/19/2022]
Abstract
Understanding the communication pathways between remote sites in proteins is of key importance for understanding their function and mechanism of action. These remain largely unexplored among the pleiotropic drug resistance (PDR) representatives of the ubiquitous superfamily of ATP-binding cassette (ABC) transporters. To identify functionally coupled residues important for the polyspecific transport by the fungal ABC multidrug transporter Cdr1p a new selection strategy, towards increased resistance to a preferred substrate of the homologous Snq2p, was applied to a library of randomly generated mutants. The single amino acid substitutions, located pseudosymmetrically in each domain of the internally duplicated protein: the H-loop of the N-terminal nucleotide binding domain (NBD1) (C363R) and in the C-terminal NBD2 region preceding Walker A (V885G). The central regions of the first transmembrane helices 1 and 7 of both transmembrane domains were also affected by the G521S/D and A1208V substitutions respectively. Although the mutants were expressed at a similar level and located correctly to the plasma membrane, they selectively affected transport of multiple drugs, including azole antifungals. The synergistic effects of combined mutations on drug resistance, drug dependent ATPase activity and transport support the view inferred from the statistical coupling analysis (SCA) of aminoacid coevolution and mutational analysis of other ABC transporter families that these residues are an important part of the conserved, allosterically coupled interdomain communication network. Our results shed new light on the communication between the pseudosymmetrically arranged domains in a fungal PDR ABC transporter and reveal its profound influence on substrate specificity.
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Affiliation(s)
- Marcin Kolaczkowski
- Department of Biophysics, Wroclaw Medical University, PL-50-368 Wroclaw, Poland.
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33
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George AM, Jones PM. Perspectives on the structure-function of ABC transporters: the Switch and Constant Contact models. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 109:95-107. [PMID: 22765920 DOI: 10.1016/j.pbiomolbio.2012.06.003] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 06/14/2012] [Indexed: 12/20/2022]
Abstract
ABC transporters constitute one of the largest protein families across the kingdoms of archaea, eubacteria and eukarya. They couple ATP hydrolysis to vectorial translocation of diverse substrates across membranes. The ABC transporter architecture comprises two transmembrane domains and two cytosolic ATP-binding cassettes. During 2002-2012, nine prokaryotic ABC transporter structures and two eukaryotic structures have been solved to medium resolution. Despite a wealth of biochemical, biophysical, and structural data, fundamental questions remain regarding the coupling of ATP hydrolysis to unidirectional substrate translocation, and the mechanistic suite of steps involved. The mechanics of the ATP cassette dimer is defined most popularly by the 'Switch Model', which proposes that hydrolysis in each protomer is sequential, and that as the sites are freed of nucleotide, the protomers lose contact across a large solvent-filled gap of 20-30 Å; as captured in several X-ray solved structures. Our 'Constant Contact' model for the operational mechanics of ATP binding and hydrolysis in the ATP-binding cassettes is derived from the 'alternating sites' model, proposed in 1995, and which requires an intrinsic asymmetry in the ATP sites, but does not require the partner protomers to lose contact. Thus one of the most debated issues regarding the function of ABC transporters is whether the cooperative mechanics of ATP hydrolysis requires the ATP cassettes to separate or remain in constant contact and this dilemma is discussed at length in this review.
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Affiliation(s)
- Anthony M George
- School of Medical and Molecular Biosciences, University of Technology Sydney, P.O. Box 123, Broadway, NSW 2007, Australia.
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34
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Ferreira RJ, Ferreira MJU, dos Santos DJVA. Insights on P-Glycoprotein’s Efflux Mechanism Obtained by Molecular Dynamics Simulations. J Chem Theory Comput 2012; 8:1853-64. [DOI: 10.1021/ct300083m] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Ricardo J. Ferreira
- Research Institute for
Medicine and Pharmaceutical
Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av.
Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Maria-José U. Ferreira
- Research Institute for
Medicine and Pharmaceutical
Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av.
Prof. Gama Pinto, 1649-003 Lisbon, Portugal
| | - Daniel J. V. A. dos Santos
- Research Institute for
Medicine and Pharmaceutical
Sciences (iMed.UL), Faculty of Pharmacy, University of Lisbon, Av.
Prof. Gama Pinto, 1649-003 Lisbon, Portugal
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35
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Inter-domain communication mechanisms in an ABC importer: a molecular dynamics study of the MalFGK2E complex. PLoS Comput Biol 2011; 7:e1002128. [PMID: 21829343 PMCID: PMC3150292 DOI: 10.1371/journal.pcbi.1002128] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 06/07/2011] [Indexed: 12/22/2022] Open
Abstract
ATP-Binding Cassette transporters are ubiquitous membrane proteins that convert the energy from ATP-binding and hydrolysis into conformational changes of the transmembrane region to allow the translocation of substrates against their concentration gradient. Despite the large amount of structural and biochemical data available for this family, it is still not clear how the energy obtained from ATP hydrolysis in the ATPase domains is “transmitted” to the transmembrane domains. In this work, we focus our attention on the consequences of hydrolysis and inorganic phosphate exit in the maltose uptake system (MalFGK2E) from Escherichia coli. The prime goal is to identify and map the structural changes occurring during an ATP-hydrolytic cycle. For that, we use extensive molecular dynamics simulations to study three potential intermediate states (with 10 replicates each): an ATP-bound, an ADP plus inorganic phosphate-bound and an ADP-bound state. Our results show that the residues presenting major rearrangements are located in the A-loop, in the helical sub-domain, and in the “EAA motif” (especially in the “coupling helices” region). Additionally, in one of the simulations with ADP we were able to observe the opening of the NBD dimer accompanied by the dissociation of ADP from the ABC signature motif, but not from its corresponding P-loop motif. This work, together with several other MD studies, suggests a common communication mechanism both for importers and exporters, in which ATP-hydrolysis induces conformational changes in the helical sub-domain region, in turn transferred to the transmembrane domains via the “coupling helices”. ABC transporters are membrane proteins that couple ATP binding and hydrolysis with the active transport of substrates across membranes. These transporters form one of the largest families of membrane proteins and they can be found in all phyla of life. Moreover, some members of this family are involved in several genetic diseases (such as cystic fibrosis) and in multidrug resistance in bacteria, fungi and mammals. In this work, we use molecular dynamics simulations to study conformational changes due to ATP hydrolysis in an ABC transporter responsible for maltose uptake in E. coli. These conformational changes arising from one side of the protein (NBDs – Nucleotide Binding domains) where ATP binds, are propagated across the protein to more distant regions. Additionally, we can observe an NBD dimer interface dissociation event upon inorganic phosphate exit. These simulations together with other theoretical studies suggest that there is a general inter-domain communication mechanism common to importers and exporters.
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36
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Gyimesi G, Ramachandran S, Kota P, Dokholyan NV, Sarkadi B, Hegedus T. ATP hydrolysis at one of the two sites in ABC transporters initiates transport related conformational transitions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2954-64. [PMID: 21840296 DOI: 10.1016/j.bbamem.2011.07.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 06/23/2011] [Accepted: 07/25/2011] [Indexed: 12/23/2022]
Abstract
ABC transporters play important roles in all types of organisms by participating in physiological and pathological processes. In order to modulate the function of ABC transporters, detailed knowledge regarding their structure and dynamics is necessary. Available structures of ABC proteins indicate three major conformations, a nucleotide-bound "bottom-closed" state with the two nucleotide binding domains (NBDs) tightly closed, and two nucleotide-free conformations, the "bottom-closed" and the "bottom-open", which differ in the extent of separation of the NBDs. However, it remains a question how the widely open conformation should be interpreted, and whether hydrolysis at one of the sites can drive conformational transitions while the NBDs remain in contact. To extend our knowledge, we have investigated the dynamic properties of the Sav1866 transporter using molecular dynamics (MD) simulations. We demonstrate that the replacement of one ATP by ADP alters the correlated motion patterns of the NBDs and the transmembrane domains (TMD). The results suggest that the hydrolysis of a single nucleotide could lead to extracellular closure, driving the transport cycle. Essential dynamics analysis of simulations suggests that single nucleotide hydrolysis can drive the system toward a "bottom-closed" apo conformation similar to that observed in the structure of the MsbA transporter. We also found significant structural instability of the "bottom-open" form of the transporters in simulations. Our results suggest that ATP hydrolysis at one of the sites promotes transport related conformational changes leading to the "bottom-closed" apo conformation, which could thus be physiologically more relevant for describing the structure of the apo state.
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Affiliation(s)
- Gergely Gyimesi
- Membrane Research Group, Hungarian Academy of Sciences, Budapest, Hungary
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