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Competition for Manganese at the Host-Pathogen Interface. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 142:1-25. [PMID: 27571690 DOI: 10.1016/bs.pmbts.2016.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Transition metals such as manganese are essential nutrients for both pathogen and host. Vertebrates exploit this necessity to combat invading microbes by restricting access to these critical nutrients, a defense known as nutritional immunity. During infection, the host uses several mechanisms to impose manganese limitation. These include removal of manganese from the phagolysosome, sequestration of extracellular manganese, and utilization of other metals to prevent bacterial acquisition of manganese. In order to cause disease, pathogens employ a variety of mechanisms that enable them to adapt to and counter nutritional immunity. These adaptations include, but are likely not limited to, manganese-sensing regulators and high-affinity manganese transporters. Even though successful pathogens can overcome host-imposed manganese starvation, this defense inhibits manganese-dependent processes, reducing the ability of these microbes to cause disease. While the full impact of host-imposed manganese starvation on bacteria is unknown, critical bacterial virulence factors such as superoxide dismutases are inhibited. This chapter will review the factors involved in the competition for manganese at the host-pathogen interface and discuss the impact that limiting the availability of this metal has on invading bacteria.
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Lin H, Andersen GR, Yatime L. Crystal structure of human S100A8 in complex with zinc and calcium. BMC STRUCTURAL BIOLOGY 2016; 16:8. [PMID: 27251136 PMCID: PMC4888247 DOI: 10.1186/s12900-016-0058-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/12/2016] [Indexed: 11/30/2022]
Abstract
Background S100 proteins are a large family of calcium binding proteins present only in vertebrates. They function intra- and extracellularly both as regulators of homeostatic processes and as potent effectors during inflammation. Among these, S100A8 and S100A9 are two major constituents of neutrophils that can assemble into homodimers, heterodimers and higher oligomeric species, including fibrillary structures found in the ageing prostate. Each of these forms assumes specific functions and their formation is dependent on divalent cations, notably calcium and zinc. In particular, zinc appears as a major regulator of S100 protein function in a disease context. Despite this central role, no structural information on how zinc bind to S100A8/S100A9 and regulates their quaternary structure is yet available. Results Here we report two crystallographic structures of calcium and zinc-loaded human S100A8. S100A8 binds two zinc ions per homodimer, through two symmetrical, all-His tetracoordination sites, revealing a classical His-Zn binding mode for the protein. Furthermore, the presence of a (Zn)2-cacodylate complex in our second crystal form induces ligand swapping within the canonical His4 zinc binding motif, thereby creating two new Zn-sites, one of which involves residues from symmetry-related molecules. Finally, we describe the calcium-induced S100A8 tetramer and reveal how zinc stabilizes this tetramer by tightening the dimer-dimer interface. Conclusions Our structures of Zn2+/Ca2+-bound hS100A8 demonstrate that S100A8 is a genuine His-Zn S100 protein. Furthermore, they show how zinc stabilizes S100A8 tetramerization and potentially mediates the formation of novel interdimer interactions. We propose that these zinc-mediated interactions may serve as a basis for the generation of larger oligomers in vivo. Electronic supplementary material The online version of this article (doi:10.1186/s12900-016-0058-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Haili Lin
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Aarhus, Denmark
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Aarhus, Denmark
| | - Laure Yatime
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK-8000, Aarhus, Denmark. .,Present address: DIMNP - UMR5235, University of Montpellier, Place Eugène Bataillon, Bât. 24 cc107, 34095, Montpellier Cedex 5, France.
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Abstract
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Metal ions and metallocofactors play important
roles in a broad
range of biochemical reactions. Accordingly, it has been estimated
that as much as 25–50% of the proteome uses transition metal
ions to carry out a variety of essential functions. The metal ions
incorporated within metalloproteins fulfill functional roles based
on chemical properties, the diversity of which arises as transition
metals can adopt different redox states and geometries, dictated by
the identity of the metal and the protein environment. The coupling
of a metal ion with an organic framework in metallocofactors, such
as heme and cobalamin, further expands the chemical functionality
of metals in biology. The three-dimensional visualization of metal
ions and complex metallocofactors within a protein scaffold is often
a starting point for enzymology, highlighting the importance of structural
characterization of metalloproteins. Metalloprotein crystallography,
however, presents a number of implicit challenges including correctly
incorporating the relevant metal or metallocofactor, maintaining the
proper environment for the protein to be purified and crystallized
(including providing anaerobic, cold, or aphotic environments), and
being mindful of the possibility of X-ray induced damage to the proteins
or incorporated metal ions. Nevertheless, the incorporated metals
or metallocofactors also present unique advantages in metalloprotein
crystallography. The significant resonance that metals undergo with
X-ray photons at wavelengths used for protein crystallography and
the rich electronic properties of metals, which provide intense and
spectroscopically unique signatures, allow a metalloprotein crystallographer
to use anomalous dispersion to determine phases for structure solution
and to use simultaneous or parallel spectroscopic techniques on single
crystals. These properties, coupled with the improved brightness of
beamlines, the ability to tune the wavelength of the X-ray beam, the
availability of advanced detectors, and the incorporation of spectroscopic
equipment at a number of synchrotron beamlines, have yielded exciting
developments in metalloprotein structure determination. Here we will
present results on the advantageous uses of metals in metalloprotein
crystallography, including using metallocofactors to obtain phasing
information, using K-edge X-ray absorption spectroscopy to identify
metals coordinated in metalloprotein crystals, and using UV–vis
spectroscopy on crystals to probe the enzymatic activity of the crystallized
protein.
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Affiliation(s)
- Sarah E. J. Bowman
- Department
of Chemistry, ‡Department of Biology, and §Howard Hughes Medical Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Jennifer Bridwell-Rabb
- Department
of Chemistry, ‡Department of Biology, and §Howard Hughes Medical Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Catherine L. Drennan
- Department
of Chemistry, ‡Department of Biology, and §Howard Hughes Medical Institute, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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Stephan JR, Nolan EM. Calcium-induced Tetramerization and Zinc Chelation Shield Human Calprotectin from Degradation by Host and Bacterial Extracellular Proteases. Chem Sci 2016; 7:1962-1975. [PMID: 26925211 PMCID: PMC4763987 DOI: 10.1039/c5sc03287c] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 11/17/2015] [Indexed: 12/19/2022] Open
Abstract
Calprotectin (CP, S100A8/S100A9 oligomer, MRP-8/14 oligomer, calgranulins A and B) is a protein component of the innate immune system that contributes to the metal-withholding response by sequestering bioavailable transition metal ions at sites of infection. Human CP employs Ca(II) ions to modulate its quaternary structure, transition metal binding properties, and antimicrobial activity. In this work, we report the discovery that Ca(II)-induced self-association of human CP to afford heterotetramers protects the protein scaffold from degradation by host serine proteases. We present the design and characterization of two new human CP-Ser variants, S100A8(C42S)(I60E)/S100A9(C3S) and S100A8(C42S)(I60K)/S100A9(C3S), that exhibit defective tetramerization properties. Analytical size exclusion chromatography and analytical ultracentrifugation reveal that both variants, hereafter I60E and I60K, persist as heterodimers in the presence of Ca(II) only, and form heterotetramers in the presence of Mn(II) only and both Ca(II) and Mn(II). Coordination to Fe(II) also causes I60E and I60K to form heterotetramers in both the absence and presence of Ca(II). The Ca(II)-bound I60E and I60K heterodimers are readily degraded by trypsin, chymotrypsin and human neutrophil elastase, whereas the Ca(II)-bound CP-Ser heterotetramers and the Ca(II)- and Mn(II)-bound I60E and I60K heterotetramers are resistant to degradation by these host proteases. The staphylococcal extracellular protease GluC cuts the S100A8 subunit of CP-Ser at the C-terminal end of residue 89 to afford a ΔSKHE variant. The GluC cleavage site is in close proximity to the His3Asp metal-binding site, which coordinates Zn(II) with high affinity, and Zn(II) chelation protects the S100A8 subunit from GluC cleavage. Taken together, these results provide new insight into how Ca(II) ions and transition metals modulate the chemistry and biology of CP, and indicate that coordination to divalent cations transforms human CP into a protease-resistant form and enables innate immune function in the hostile conditions of an infection site.
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Affiliation(s)
- Jules R. Stephan
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
| | - Elizabeth M. Nolan
- Department of Chemistry , Massachusetts Institute of Technology , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
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55
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Cunden LS, Gaillard A, Nolan EM. Calcium Ions Tune the Zinc-Sequestering Properties and Antimicrobial Activity of Human S100A12. Chem Sci 2016; 7:1338-1348. [PMID: 26913170 PMCID: PMC4762610 DOI: 10.1039/c5sc03655k] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 10/26/2015] [Indexed: 12/15/2022] Open
Abstract
Human S100A12 is a host-defense protein expressed and released by neutrophils that contributes to innate immunity. Apo S100A12 is a 21-kDa antiparallel homodimer that harbors two Ca(II)-binding EF-hand domains per subunit and exhibits two His3Asp motifs for chelating transition metal ions at the homodimer interface. In this work, we present results from metal-binding studies and microbiology assays designed to ascertain whether Ca(II) ions modulate the Zn(II)-binding properties of S100A12 and further evaluate the antimicrobial properties of this protein. Our metal depletion studies reveal that Ca(II) ions enhance the ability of S100A12 to sequester Zn(II) from microbial growth media. We report that human S100A12 has antifungal activity against Candida albicans, C. krusei, C. glabrata and C. tropicalis, all of which cause human disease. This antifungal activity is Ca(II)-dependent and requires the His3Asp metal-binding sites. We expand upon prior studies of the antibacterial activity of S100A12 and report Ca(II)-dependent and strain-selective behavior. S100A12 exhibited in vitro growth inhibitory activity against Listeria monocytogenes. In contrast, S100A12 had negligible effect on the growth of Escherichia coli K-12 and Pseudomonas aeruginosa PAO1. Loss of functional ZnuABC, a high-affinity Zn(II) import system, increased the susceptibility of E. coli and P. aeruginosa to S100A12, indicating that S100A12 deprives these mutant strains of Zn(II). To evaluate the Zn(II)-binding sites of S100A12 in solution, we present studies using Co(II) as a spectroscopic probe and chromophoric small-molecule chelators in Zn(II) competition titrations. We confirm that S100A12 binds Zn(II) with a 2:1 stoichiometry, and our data indicate sub-nanomolar affinity binding. Taken together, these data support a model whereby S100A12 uses Ca(II) ions to tune its Zn(II)-chelating properties and antimicrobial activity.
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Affiliation(s)
- Lisa S. Cunden
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
| | - Aleth Gaillard
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
| | - Elizabeth M. Nolan
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , MA 02139 , USA . ; Fax: +1-617-324-0505 ; Tel: +1-617-452-2495
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56
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Morrow JR. Editorial for the ACS Select Virtual Issue on Emerging Investigators in Bioinorganic Chemistry. Inorg Chem 2015. [DOI: 10.1021/acs.inorgchem.5b02597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Bou-Abdallah F, Giffune TR. The thermodynamics of protein interactions with essential first row transition metals. Biochim Biophys Acta Gen Subj 2015; 1860:879-891. [PMID: 26569121 DOI: 10.1016/j.bbagen.2015.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 10/27/2015] [Accepted: 11/01/2015] [Indexed: 12/16/2022]
Abstract
BACKGROUND The binding of metal ions to proteins is a crucial process required for their catalytic activity, structural stability and/or functional regulation. Isothermal titration calorimetry provides a wealth of fundamental information which when combined with structural data allow for a much deeper understanding of the underlying molecular mechanism. SCOPE OF REVIEW A rigorous understanding of any molecular interaction requires in part an in-depth quantification of its thermodynamic properties. Here, we provide an overview of recent studies that have used ITC to quantify the interaction of essential first row transition metals with relevant proteins and highlight major findings from these thermodynamic studies. GENERAL SIGNIFICANCE The thermodynamic characterization of metal ion-protein interactions is one important step to understanding the role that metal ions play in living systems. Such characterization has important implications not only to elucidating proteins' structure-function relationships and biological properties but also in the biotechnology sector, medicine and drug design particularly since a number of metal ions are involved in several neurodegenerative diseases. MAJOR CONCLUSIONS Isothermal titration calorimetry measurements can provide complete thermodynamic profiles of any molecular interaction through the simultaneous determination of the reaction binding stoichiometry, binding affinity as well as the enthalpic and entropic contributions to the free energy change thus enabling a more in-depth understanding of the nature of these interactions.
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Affiliation(s)
- Fadi Bou-Abdallah
- State University of New York at Potsdam, Potsdam, NY 13676, United States.
| | - Thomas R Giffune
- State University of New York at Potsdam, Potsdam, NY 13676, United States
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58
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Nakashige TG, Zhang B, Krebs C, Nolan EM. Human calprotectin is an iron-sequestering host-defense protein. Nat Chem Biol 2015; 11:765-71. [PMID: 26302479 PMCID: PMC4575267 DOI: 10.1038/nchembio.1891] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 07/01/2015] [Indexed: 01/04/2023]
Abstract
Human calprotectin (CP) is a metal-chelating antimicrobial protein of the innate immune response. The current working model states that CP sequesters manganese and zinc from pathogens. We report the discovery that CP chelates iron and deprives bacteria of this essential nutrient. Elemental analysis of CP-treated growth medium establishes that CP reduces the concentrations of manganese, iron and zinc. Microbial growth studies reveal that iron depletion by CP contributes to the growth inhibition of bacterial pathogens. Biochemical investigations demonstrate that CP coordinates Fe(II) at an unusual hexahistidine motif, and the Mössbauer spectrum of (57)Fe(II)-bound CP is consistent with coordination of high-spin Fe(II) at this site (δ = 1.20 mm/s, ΔEQ = 1.78 mm/s). In the presence of Ca(II), CP turns on its iron-sequestering function and exhibits subpicomolar affinity for Fe(II). Our findings expand the biological coordination chemistry of iron and support a previously unappreciated role for CP in mammalian iron homeostasis.
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Affiliation(s)
- Toshiki G. Nakashige
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Bo Zhang
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
| | - Carsten Krebs
- Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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59
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Tao L, Stich TA, Butterfield CN, Romano CA, Spiro TG, Tebo BM, Casey WH, Britt RD. Mn(II) Binding and Subsequent Oxidation by the Multicopper Oxidase MnxG Investigated by Electron Paramagnetic Resonance Spectroscopy. J Am Chem Soc 2015; 137:10563-75. [DOI: 10.1021/jacs.5b04331] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | | | - Cristina N. Butterfield
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Christine A. Romano
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Thomas G. Spiro
- Department
of Chemistry, University of Washington, Box 351700, Seattle, Washington 98195, United States
| | - Bradley M. Tebo
- Division of Environmental and Biomolecular Systems, Institute of Environmental Health, Oregon Health & Science University, Portland, Oregon 97239, United States
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Zackular JP, Chazin WJ, Skaar EP. Nutritional Immunity: S100 Proteins at the Host-Pathogen Interface. J Biol Chem 2015; 290:18991-8. [PMID: 26055713 DOI: 10.1074/jbc.r115.645085] [Citation(s) in RCA: 170] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The S100 family of EF-hand calcium (Ca(2+))-binding proteins is essential for a wide range of cellular functions. During infection, certain S100 proteins act as damage-associated molecular patterns (DAMPs) and interact with pattern recognition receptors to modulate inflammatory responses. In addition, these inflammatory S100 proteins have potent antimicrobial properties and are essential components of the immune response to invading pathogens. In this review, we focus on S100 proteins that exhibit antimicrobial properties through the process of metal limitation, termed nutritional immunity, and discuss several recent advances in our understanding of S100 protein-mediated metal sequestration at the site of infection.
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Affiliation(s)
- Joseph P Zackular
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and
| | - Walter J Chazin
- the Departments of Biochemistry and Chemistry, and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37232
| | - Eric P Skaar
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 and
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61
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Alies B, Wiener JD, Franz KJ. A prochelator peptide designed to use heterometallic cooperativity to enhance metal ion affinity. Chem Sci 2015; 6:3606-3610. [PMID: 29511523 PMCID: PMC5659173 DOI: 10.1039/c5sc00602c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 04/22/2015] [Indexed: 12/27/2022] Open
Abstract
A peptide has been designed so that its chelating affinity for one type of metal ion regulates its affinity for a second, different type of metal ion. The prochelator peptide (PCP), which is a fusion of motifs evocative of calcium loops and zinc fingers, forms a 1 : 2 Zn : peptide complex at pH 7.4 that increases its affinity for Zn2+ ∼3-fold in the presence of Tb3+ (log β2 from 13.8 to 14.3), while the 1 : 1 luminescent complex with Tb3+ is brighter, longer lived, and 20-fold tighter in the presence of Zn2+ (log K from 6.2 to 7.5). This unique example of cooperative, heterometallic allostery in a biologically compatible construct suggests the possibility of designing conditionally active metal-binding agents that could respond to dynamic changes in cellular metal status.
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Affiliation(s)
- Bruno Alies
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , USA .
| | - Jacob D Wiener
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , USA .
| | - Katherine J Franz
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , USA .
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