1
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Lee J, Dalton RA, Baslé A, Vita N, Dennison C. Important Structural Features of Thiolate-Rich Four-Helix Bundles for Cu(I) Uptake and Removal. Inorg Chem 2023; 62:6617-6628. [PMID: 37057906 PMCID: PMC10155185 DOI: 10.1021/acs.inorgchem.2c04490] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Indexed: 04/15/2023]
Abstract
A family of bacterial copper storage proteins (the Csps) possess thiolate-lined four-helix bundles whose cores can be filled with Cu(I) ions. The majority of Csps are cytosolic (Csp3s), and in vitro studies carried out to date indicate that the Csp3s from Methylosinus trichosporium OB3b (MtCsp3), Bacillus subtilis (BsCsp3), and Streptomyces lividans (SlCsp3) are alike. Bioinformatics have highlighted homologues with potentially different Cu(I)-binding properties from these characterized "classical" Csp3s. Determination herein of the crystal structure of the protein (RkCsp3) from the methanotroph Methylocystis sp. strain Rockwell with Cu(I) bound identifies this as the first studied example of a new subgroup of Csp3s. The most significant structural difference from classical Csp3s is the presence of only two Cu(I) sites at the mouth of the bundle via which Cu(I) ions enter and leave. This is due to the absence of three Cys residues and a His-containing motif, which allow classical Csp3s to bind five to six Cu(I) ions in this region. Regardless, RkCsp3 exhibits rapid Cu(I) binding and the fastest measured Cu(I) removal rate for a Csp3 when using high-affinity ligands as surrogate partners. New experiments on classical Csp3s demonstrate that their His-containing motif is not essential for fast Cu(I) uptake and removal. Other structural features that could be important for these functionally relevant in vitro properties are discussed.
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Affiliation(s)
- Jaeick Lee
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Rosemary A. Dalton
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Arnaud Baslé
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
| | - Nicolas Vita
- Biosciences Institute, Newcastle University, Newcastle
upon Tyne NE2 4HH, U.K.
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2
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Cutsail G, Schott-Verdugo S, Müller L, DeBeer S, Groth G, Gohlke H. Spectroscopic and QM/MM studies of the Cu(I) binding site of the plant ethylene receptor ETR1. Biophys J 2022; 121:3862-3873. [PMID: 36086818 PMCID: PMC9674993 DOI: 10.1016/j.bpj.2022.09.007] [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: 06/15/2022] [Revised: 08/17/2022] [Accepted: 09/06/2022] [Indexed: 11/15/2022] Open
Abstract
Herein, we present, to our knowledge, the first spectroscopic characterization of the Cu(I) active site of the plant ethylene receptor ETR1. The x-ray absorption (XAS) and extended x-ray absorption fine structure (EXAFS) spectroscopies presented here establish that ETR1 has a low-coordinate Cu(I) site. The EXAFS resolves a mixed first coordination sphere of N/O and S scatterers at distances consistent with potential histidine and cysteine residues. This finding agrees with the coordination of residues C65 and H69 to the Cu(I) site, which are critical for ethylene activity and well conserved. Furthermore, the Cu K-edge XAS and EXAFS of ETR1 exhibit spectroscopic changes upon addition of ethylene that are attributed to modifications in the Cu(I) coordination environment, suggestive of ethylene binding. Results from umbrella sampling simulations of the proposed ethylene binding helix of ETR1 at a mixed quantum mechanics/molecular mechanics level agree with the EXAFS fit distance changes upon ethylene binding, particularly in the increase of the distance between H69 and Cu(I), and yield binding energetics comparable with experimental dissociation constants. The observed changes in the copper coordination environment might be the triggering signal for the transmission of the ethylene response.
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Affiliation(s)
- George Cutsail
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany; Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstrasse 7, Essen, Germany
| | - Stephan Schott-Verdugo
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Bioinformatics), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Lena Müller
- Institut für Biochemische Pflanzenphysiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - Georg Groth
- Institut für Biochemische Pflanzenphysiologie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC), Institute of Biological Information Processing (IBI-7: Structural Bioinformatics), and Institute of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, Jülich, Germany; Institut für Pharmazeutische und Medizinische Chemie, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany.
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3
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Novoa-Aponte L, Argüello JM. Unique underlying principles shaping copper homeostasis networks. J Biol Inorg Chem 2022; 27:509-528. [PMID: 35802193 PMCID: PMC9470648 DOI: 10.1007/s00775-022-01947-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 05/27/2022] [Indexed: 12/27/2022]
Abstract
Abstract Copper is essential in cells as a cofactor for key redox enzymes. Bacteria have acquired molecular components that sense, uptake, distribute, and expel copper ensuring that cuproenzymes are metallated and steady-state metal levels are maintained. Toward preventing deleterious reactions, proteins bind copper ions with high affinities and transfer the metal via ligand exchange, warranting that copper ions are always complexed. Consequently, the directional copper distribution within cell compartments and across cell membranes requires specific dynamic interactions and metal exchange between cognate holo-apo protein partners. These metal exchange reactions are determined by thermodynamic and kinetics parameters and influenced by mass action. Then, copper distribution can be conceptualized as a molecular system of singular interacting elements that maintain a physiological copper homeostasis. This review focuses on the impact of copper high-affinity binding and exchange reactions on the homeostatic mechanisms, the conceptual models to describe the cell as a homeostatic system, the various molecule functions that contribute to copper homeostasis, and the alternative system architectures responsible for copper homeostasis in model bacteria. Graphical Abstract ![]()
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Affiliation(s)
- Lorena Novoa-Aponte
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 60 Prescott St, Worcester, MA, 01605, USA.,Genetics and Metabolism Section, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, 20892, USA
| | - José M Argüello
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, 60 Prescott St, Worcester, MA, 01605, USA.
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4
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Wang Y, Hu H, Yuan S, LI Y, Cao K, Sun H, Liu Y. Cuprous Ions can Disrupt Structure and Functions of the RING Finger Domain of RNF11. Inorg Chem Front 2022. [DOI: 10.1039/d2qi00631f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper is an essential element that plays crucial roles in a variety of biological processes, while excessive copper is harmful to cells. RNF11 is a RING finger protein associated with...
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5
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Canonica F, Klose D, Ledermann R, Sauer MM, Abicht HK, Quade N, Gossert AD, Chesnov S, Fischer HM, Jeschke G, Hennecke H, Glockshuber R. Structural basis and mechanism for metallochaperone-assisted assembly of the Cu A center in cytochrome oxidase. SCIENCE ADVANCES 2019; 5:eaaw8478. [PMID: 31392273 PMCID: PMC6669012 DOI: 10.1126/sciadv.aaw8478] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
The mechanisms underlying the biogenesis of the structurally unique, binuclear Cu1.5+•Cu1.5+ redox center (CuA) on subunit II (CoxB) of cytochrome oxidases have been a long-standing mystery. Here, we reconstituted the CoxB•CuA center in vitro from apo-CoxB and the holo-forms of the copper transfer chaperones ScoI and PcuC. A previously unknown, highly stable ScoI•Cu2+•CoxB complex was shown to be rapidly formed as the first intermediate in the pathway. Moreover, our structural data revealed that PcuC has two copper-binding sites, one each for Cu1+ and Cu2+, and that only PcuC•Cu1+•Cu2+ can release CoxB•Cu2+ from the ScoI•Cu2+•CoxB complex. The CoxB•CuA center was then formed quantitatively by transfer of Cu1+ from a second equivalent of PcuC•Cu1+•Cu2+ to CoxB•Cu2+. This metalation pathway is consistent with all available in vivo data and identifies the sources of the Cu ions required for CuA center formation and the order of their delivery to CoxB.
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Affiliation(s)
- Fabia Canonica
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Daniel Klose
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | | | - Maximilian M. Sauer
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Helge K. Abicht
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Nick Quade
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Alvar D. Gossert
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Serge Chesnov
- Functional Genomics Center Zurich, University of Zurich/ETH Zurich, Zurich, Switzerland
| | | | - Gunnar Jeschke
- Laboratory of Physical Chemistry, ETH Zurich, Zurich, Switzerland
| | - Hauke Hennecke
- Institute of Microbiology, ETH Zurich, Zurich, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
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6
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Bennett SP, Soriano-Laguna MJ, Bradley JM, Svistunenko DA, Richardson DJ, Gates AJ, Le Brun NE. NosL is a dedicated copper chaperone for assembly of the Cu Z center of nitrous oxide reductase. Chem Sci 2019; 10:4985-4993. [PMID: 31183047 PMCID: PMC6530538 DOI: 10.1039/c9sc01053j] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/01/2019] [Indexed: 11/21/2022] Open
Abstract
Nitrous oxide reductase (N2OR) is the terminal enzyme of the denitrification pathway of soil bacteria that reduces the greenhouse gas nitrous oxide (N2O) to dinitrogen. In addition to a binuclear CuA site that functions in electron transfer, the active site of N2OR features a unique tetranuclear copper cluster bridged by inorganic sulfide, termed CuZ. In copper-limited environments, N2OR fails to function, resulting in truncation of denitrification and rising levels of N2O released by cells to the atmosphere, presenting a major environmental challenge. Here we report studies of nosL from Paracoccus denitrificans, which is part of the nos gene cluster, and encodes a putative copper binding protein. A Paracoccus denitrificans ΔnosL mutant strain had no denitrification phenotype under copper-sufficient conditions but failed to reduce N2O under copper-limited conditions. N2OR isolated from ΔnosL cells was found to be deficient in copper and to exhibit attenuated activity. UV-visible absorbance spectroscopy revealed that bands due to the CuA center were unaffected, while those corresponding to the CuZ center were significantly reduced in intensity. In vitro studies of a soluble form of NosL without its predicted membrane anchor showed that it binds one Cu(i) ion per protein with attomolar affinity, but does not bind Cu(ii). Together, the data demonstrate that NosL is a copper-binding protein specifically required for assembly of the CuZ center of N2OR, and thus represents the first characterised assembly factor for the CuZ active site of this key environmental enzyme, which is globally responsible for the destruction of a potent greenhouse gas.
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Affiliation(s)
- Sophie P Bennett
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Manuel J Soriano-Laguna
- Centre for Molecular and Structural Biochemistry , School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Dimitri A Svistunenko
- School of Biological Sciences , University of Essex , Wivenhoe Park , Colchester CO4 3SQ , UK
| | - David J Richardson
- Centre for Molecular and Structural Biochemistry , School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Andrew J Gates
- Centre for Molecular and Structural Biochemistry , School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK .
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7
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Baslé A, El Ghazouani A, Lee J, Dennison C. Insight into Metal Removal from Peptides that Sequester Copper for Methane Oxidation. Chemistry 2018; 24:4515-4518. [PMID: 29365216 PMCID: PMC5947558 DOI: 10.1002/chem.201706035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Indexed: 01/08/2023]
Abstract
Methanobactins (Mbns) are modified peptides that sequester copper (Cu) methanotrophs use to oxidize methane. Limited structural information is available for this class of natural products, as is an understanding of how cells are able to utilize Mbn-bound Cu. The crystal structure of Methylosinus sporium NR3K CuI -Mbn provides further information about the structural diversity of Mbns and the first insight into their Cu-release mechanism. Nitrogen ligands from oxazolone and pyrazinediol rings chelate CuI along with adjacent coordinating sulfurs from thioamides. In vitro solution data are consistent with a CuI -Mbn monomer as found for previously characterized Mbns. In the crystal structure, the N-terminal region has undergone a conformational change allowing the formation of a CuI2 -Mbn2 dimer with CuI sites bound by chelating units from adjacent chains. Such a structural alteration will facilitate CuI release from Mbns.
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Affiliation(s)
- Arnaud Baslé
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Abdelnasser El Ghazouani
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Jaeick Lee
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
| | - Christopher Dennison
- Institute for Cell and Molecular BiosciencesMedical SchoolNewcastle UniversityNewcastle upon TyneNE2 4HHUK
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8
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Kay KL, Zhou L, Tenori L, Bradley JM, Singleton C, Kihlken MA, Ciofi-Baffoni S, Le Brun NE. Kinetic analysis of copper transfer from a chaperone to its target protein mediated by complex formation. Chem Commun (Camb) 2018; 53:1397-1400. [PMID: 28078344 DOI: 10.1039/c6cc08966f] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Chaperone proteins that traffic copper around the cell minimise its toxicity by maintaining it in a tightly bound form. The transfer of copper from chaperones to target proteins is promoted by complex formation, but the kinetic characteristics of transfer have yet to be demonstrated for any chaperone-target protein pair. Here we report studies of copper transfer between the Atx1-type chaperone CopZ from Bacillus subtilis and the soluble domains of its cognate P-type ATPase transporter, CopAab. Transfer of copper from CopZ to CopAab was found to occur rapidly, with a rate constant at 25 °C of ∼267 s-1, many orders of magnitude higher than that for Cu(i) dissociation from CopZ in the absence of CopAab. The data demonstrate that complex formation between CopZ and CopAab, evidence for which is provided by NMR and electrospray ionisation mass spectrometry, dramatically enhances the rate of Cu(i) dissociation from CopZ.
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Affiliation(s)
- Kristine L Kay
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Liang Zhou
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Leonardo Tenori
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Chloe Singleton
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Margaret A Kihlken
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
| | - Simone Ciofi-Baffoni
- Magnetic Resonance Center CERM and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019, Sesto Fiorentino, Florence, Italy
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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9
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Abstract
Copper is essential for most organisms as a cofactor for key enzymes involved in fundamental processes such as respiration and photosynthesis. However, copper also has toxic effects in cells, which is why eukaryotes and prokaryotes have evolved mechanisms for safe copper handling. A new family of bacterial proteins uses a Cys-rich four-helix bundle to safely store large quantities of Cu(I). The work leading to the discovery of these proteins, their properties and physiological functions, and how their presence potentially impacts the current views of bacterial copper handling and use are discussed in this review.
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Affiliation(s)
- Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom.
| | - Sholto David
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Jaeick Lee
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
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10
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Vita N, Landolfi G, Baslé A, Platsaki S, Lee J, Waldron KJ, Dennison C. Bacterial cytosolic proteins with a high capacity for Cu(I) that protect against copper toxicity. Sci Rep 2016; 6:39065. [PMID: 27991525 PMCID: PMC5171941 DOI: 10.1038/srep39065] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/16/2016] [Indexed: 01/23/2023] Open
Abstract
Bacteria are thought to avoid using the essential metal ion copper in their cytosol due to its toxicity. Herein we characterize Csp3, the cytosolic member of a new family of bacterial copper storage proteins from Methylosinus trichosporium OB3b and Bacillus subtilis. These tetrameric proteins possess a large number of Cys residues that point into the cores of their four-helix bundle monomers. The Csp3 tetramers can bind a maximum of approximately 80 Cu(I) ions, mainly via thiolate groups, with average affinities in the (1–2) × 1017 M−1 range. Cu(I) removal from these Csp3s by higher affinity potential physiological partners and small-molecule ligands is very slow, which is unexpected for a metal-storage protein. In vivo data demonstrate that Csp3s prevent toxicity caused by the presence of excess copper. Furthermore, bacteria expressing Csp3 accumulate copper and are able to safely maintain large quantities of this metal ion in their cytosol. This suggests a requirement for storing copper in this compartment of Csp3-producing bacteria.
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Affiliation(s)
- Nicolas Vita
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Gianpiero Landolfi
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Arnaud Baslé
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Semeli Platsaki
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Jaeick Lee
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Kevin J Waldron
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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11
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Quan X, Uddin R, Heiskanen A, Parmvi M, Nilson K, Donolato M, Hansen MF, Rena G, Boisen A. The copper binding properties of metformin--QCM-D, XPS and nanobead agglomeration. Chem Commun (Camb) 2016; 51:17313-6. [PMID: 26462973 DOI: 10.1039/c5cc04321b] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Study of the copper binding properties of metformin is important for revealing its mechanism of action as a first-line type-2 diabetes drug. A quantitative investigation of interactions between metformin and L-cysteine-copper complexes was performed. The results suggest that metformin could interact with biological copper, which plays a key role in mitochondrial function.
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Affiliation(s)
- Xueling Quan
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Rokon Uddin
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Arto Heiskanen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Mattias Parmvi
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Katharina Nilson
- DTU DANCHIP, Technical University of Denmark, Building 347, Kgs. Lyngby DK-2800, Denmark
| | - Marco Donolato
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Mikkel F Hansen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
| | - Graham Rena
- Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, UK
| | - Anja Boisen
- Department of Micro- and Nanotechnology, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
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12
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Kay KL, Hamilton CJ, Le Brun NE. Mass spectrometry of B. subtilis CopZ: Cu(i)-binding and interactions with bacillithiol. Metallomics 2016; 8:709-19. [DOI: 10.1039/c6mt00036c] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mass spectrometry reveals a high resolution overview of species formed by CopZ and Cu(i), and the effects of the physiological low molecular weight thiol bacillithiol.
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Affiliation(s)
- Kristine L. Kay
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich, UK
| | | | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich, UK
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13
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Fukuhara T, Kobayashi K, Kanayama Y, Enomoto SI, Kondo T, Tsunekawa N, Nemoto M, Ogasawara N, Inagaki K, Tamura T. Identification and characterization of the zosA gene involved in copper uptake in Bacillus subtilis 168. Biosci Biotechnol Biochem 2015; 80:600-9. [PMID: 26566138 DOI: 10.1080/09168451.2015.1107462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
DL-Penicillamine, a copper-specific metal chelator, remarkably suppressed the growth of Bacillus subtilis 168 when added to a synthetic medium under Cu(2+) limitation. DNA microarray and screening of 2,602 knockout mutants showed that the zosA gene was de-repressed in the presence of 0.1% dl-penicillamine, and that the zosA mutant was sensitive to dl-penicillamine medium. The zosA mutant delayed the growth under Cu-limitation even without the chelator, and the sensitivity to dl-penicillamine was reversed by induction using 0.3 mM IPTG and the Pspac promoter inserted directly upstream of the zosA gene. Furthermore, the zosA mutant showed elevated tolerance of excessive Cu(2+) but not of excessive Zn(2+) added to LB and synthetic media. Homology modeling of the ZosA protein suggested that the protein can fold itself into essential domains for constituting a metal transporting ATPase. Our study suggests that zosA is a candidate gene involved in copper uptake.
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Affiliation(s)
- Takahiro Fukuhara
- a Graduate School of Life and Environmental Science , Okayama University , Okayama , Japan
| | - Kazuo Kobayashi
- b Graduate School of Information Science , Nara Institute of Science & Technology , Ikoma , Japan
| | - Yousuke Kanayama
- c Laboratory of Multiple Molecular Imaging Research , Center for Molecular Imaging Science, RIKEN Kobe Institute , Hyogo , Japan
| | - Shu-ichi Enomoto
- c Laboratory of Multiple Molecular Imaging Research , Center for Molecular Imaging Science, RIKEN Kobe Institute , Hyogo , Japan
| | - Taeko Kondo
- a Graduate School of Life and Environmental Science , Okayama University , Okayama , Japan
| | - Naoki Tsunekawa
- d Institute of Molecular and Cellular Biosciences , The University of Tokyo , Tokyo , Japan
| | - Michiko Nemoto
- a Graduate School of Life and Environmental Science , Okayama University , Okayama , Japan
| | - Naotake Ogasawara
- b Graduate School of Information Science , Nara Institute of Science & Technology , Ikoma , Japan
| | - Kenji Inagaki
- a Graduate School of Life and Environmental Science , Okayama University , Okayama , Japan
| | - Takashi Tamura
- a Graduate School of Life and Environmental Science , Okayama University , Okayama , Japan.,e PRESTO, Japan Science and Technology Agency , Tokyo , Japan
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14
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Mattle D, Zhang L, Sitsel O, Pedersen LT, Moncelli MR, Tadini-Buoninsegni F, Gourdon P, Rees DC, Nissen P, Meloni G. A sulfur-based transport pathway in Cu+-ATPases. EMBO Rep 2015; 16:728-40. [PMID: 25956886 PMCID: PMC4467857 DOI: 10.15252/embr.201439927] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 03/13/2015] [Accepted: 03/31/2015] [Indexed: 11/09/2022] Open
Abstract
Cells regulate copper levels tightly to balance the biogenesis and integrity of copper centers in vital enzymes against toxic levels of copper. PIB -type Cu(+)-ATPases play a central role in copper homeostasis by catalyzing the selective translocation of Cu(+) across cellular membranes. Crystal structures of a copper-free Cu(+)-ATPase are available, but the mechanism of Cu(+) recognition, binding, and translocation remains elusive. Through X-ray absorption spectroscopy, ATPase activity assays, and charge transfer measurements on solid-supported membranes using wild-type and mutant forms of the Legionella pneumophila Cu(+)-ATPase (LpCopA), we identify a sulfur-lined metal transport pathway. Structural analysis indicates that Cu(+) is bound at a high-affinity transmembrane-binding site in a trigonal-planar coordination with the Cys residues of the conserved CPC motif of transmembrane segment 4 (C382 and C384) and the conserved Met residue of transmembrane segment 6 (M717 of the MXXXS motif). These residues are also essential for transport. Additionally, the studies indicate essential roles of other conserved intramembranous polar residues in facilitating copper binding to the high-affinity site and subsequent release through the exit pathway.
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Affiliation(s)
- Daniel Mattle
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Limei Zhang
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Oleg Sitsel
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Lotte Thue Pedersen
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Maria Rosa Moncelli
- Department of Chemistry 'Ugo Schiff', University of Florence, Sesto Fiorentino, Italy
| | | | - Pontus Gourdon
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Douglas C Rees
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
| | - Poul Nissen
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark
| | - Gabriele Meloni
- Centre for Membrane Pumps in Cells and Disease - PUMPkin, Department of Molecular Biology and Genetics, Danish National Research Foundation Aarhus University, Aarhus C, Denmark Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, USA
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15
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Drees SL, Beyer DF, Lenders-Lomscher C, Lübben M. Distinct functions of serial metal-binding domains in the Escherichia coli P1 B -ATPase CopA. Mol Microbiol 2015; 97:423-38. [PMID: 25899340 DOI: 10.1111/mmi.13038] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2015] [Indexed: 12/17/2022]
Abstract
P1 B -ATPases are among the most common resistance factors to metal-induced stress. Belonging to the superfamily of P-type ATPases, they are capable of exporting transition metal ions at the expense of adenosine triphosphate (ATP) hydrolysis. P1 B -ATPases share a conserved structure of three cytoplasmic domains linked by a transmembrane domain. In addition, they possess a unique class of domains located at the N-terminus. In bacteria, these domains are primarily associated with metal binding and either occur individually or as serial copies of each other. Within this study, the roles of the two adjacent metal-binding domains (MBDs) of CopA, the copper export ATPase of Escherichia coli were investigated. From biochemical and physiological data, we deciphered the protein-internal pathway of copper and demonstrate the distal N-terminal MBD to possess a function analogous to the metallochaperones of related prokaryotic copper resistance systems, that is its involvement in the copper transfer to the membrane-integral ion-binding sites of CopA. In contrast, the proximal domain MBD2 has a regulatory role by suppressing the catalytic activity of CopA in absence of copper. Furthermore, we propose a general functional divergence of tandem MBDs in P1 B -ATPases, which is governed by the length of the inter-domain linker.
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Affiliation(s)
- Steffen L Drees
- Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany
| | - Dominik F Beyer
- Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany
| | | | - Mathias Lübben
- Department of Biophysics, Ruhr University Bochum, Universitätsstr. 150, D-44801, Bochum, Germany
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16
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Evolution of a plant-specific copper chaperone family for chloroplast copper homeostasis. Proc Natl Acad Sci U S A 2014; 111:E5480-7. [PMID: 25468978 DOI: 10.1073/pnas.1421545111] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Metallochaperones traffic copper (Cu(+)) from its point of entry at the plasma membrane to its destination. In plants, one destination is the chloroplast, which houses plastocyanin, a Cu-dependent electron transfer protein involved in photosynthesis. We present a previously unidentified Cu(+) chaperone that evolved early in the plant lineage by an alternative-splicing event of the pre-mRNA encoding the chloroplast P-type ATPase in Arabidopsis 1 (PAA1). In several land plants, recent duplication events created a separate chaperone-encoding gene coincident with loss of alternative splicing. The plant-specific Cu(+) chaperone delivers Cu(+) with specificity for PAA1, which is flipped in the envelope relative to prototypical bacterial ATPases, compatible with a role in Cu(+) import into the stroma and consistent with the canonical catalytic mechanism of these enzymes. The ubiquity of the chaperone suggests conservation of this Cu(+)-delivery mechanism and provides a unique snapshot into the evolution of a Cu(+) distribution pathway. We also provide evidence for an interaction between PAA2, the Cu(+)-ATPase in thylakoids, and the Cu(+)-chaperone for Cu/Zn superoxide dismutase (CCS), uncovering a Cu(+) network that has evolved to fine-tune Cu(+) distribution.
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17
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Chaplin AK, Tan BG, Vijgenboom E, Worrall JAR. Copper trafficking in the CsoR regulon of Streptomyces lividans. Metallomics 2014; 7:145-55. [PMID: 25409712 DOI: 10.1039/c4mt00250d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In the actinobacterium Streptomyces lividans copper homeostasis is controlled through the action of the metalloregulator CsoR. Under copper stress, cuprous ions bind to apo-CsoR resulting in the transcriptional derepression of genes encoding for copper efflux systems involving CopZ-like copper chaperones and CopA-like P-type ATPases. Whether CsoR obtains copper via a protein-protein mediated trafficking mechanism is unknown. In this study we have characterised the copper trafficking properties of two S. lividans CopZ proteins (SLI_1317 and SLI_3079) under the transcriptional control of a CsoR (SLI_4375). Our findings indicate that both CopZ-proteins have cysteine residues in the Cu(i) binding MX1CX2X3C motif with acid-base properties that are modulated for a high cuprous ion affinity and favourable Cu(i)-exchange with a target. Using electrophoretic mobility shift assays transfer of Cu(i) is shown to occur in a unidirectional manner from the CopZ to the CsoR. This transfer proceeds via a shallow thermodynamic affinity gradient and is also kinetically favoured through the modulation of the acid-base properties of the cysteine residues in the Cys2His cuprous ion binding motif of CsoR. Using RNA-seq coupled with the mechanistic insights of Cu(i) transfer between CopZ and CsoR in vitro, we propose a copper trafficking pathway for the CsoR regulon that initially involves the buffering of cytosolic copper by three CopZ chaperones followed by transfer of Cu(i) to CsoR to illicit a transcriptional response.
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Affiliation(s)
- Amanda K Chaplin
- School of Biological Science, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK.
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18
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Marques SS, Magalhães LM, Tóth IV, Segundo MA. Insights on antioxidant assays for biological samples based on the reduction of copper complexes-the importance of analytical conditions. Int J Mol Sci 2014; 15:11387-402. [PMID: 24968275 PMCID: PMC4139788 DOI: 10.3390/ijms150711387] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 12/20/2022] Open
Abstract
Total antioxidant capacity assays are recognized as instrumental to establish antioxidant status of biological samples, however the varying experimental conditions result in conclusions that may not be transposable to other settings. After selection of the complexing agent, reagent addition order, buffer type and concentration, copper reducing assays were adapted to a high-throughput scheme and validated using model biological antioxidant compounds of ascorbic acid, Trolox (a soluble analogue of vitamin E), uric acid and glutathione. A critical comparison was made based on real samples including NIST-909c human serum certified sample, and five study samples. The validated method provided linear range up to 100 µM Trolox, (limit of detection 2.3 µM; limit of quantification 7.7 µM) with recovery results above 85% and precision <5%. The validated developed method with an increased sensitivity is a sound choice for assessment of TAC in serum samples.
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Affiliation(s)
- Sara S Marques
- REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - Luís M Magalhães
- REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - Ildikó V Tóth
- REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - Marcela A Segundo
- REQUIMTE, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
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19
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Puno MR, Patel NA, Møller SG, Robinson CV, Moody PCE, Odell M. Structure of Cu(I)-bound DJ-1 reveals a biscysteinate metal binding site at the homodimer interface: insights into mutational inactivation of DJ-1 in Parkinsonism. J Am Chem Soc 2013; 135:15974-7. [PMID: 24144264 DOI: 10.1021/ja406010m] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The Parkinsonism-associated protein DJ-1 has been suggested to activate the Cu-Zn superoxide dismutase (SOD1) by providing its copper cofactor. The structural and chemical means by which DJ-1 could support this function is unknown. In this study, we characterize the molecular interaction of DJ-1 with Cu(I). Mass spectrometric analysis indicates binding of one Cu(I) ion per DJ-1 homodimer. The crystal structure of DJ-1 bound to Cu(I) confirms metal coordination through a docking accessible biscysteinate site formed by juxtaposed cysteine residues at the homodimer interface. Spectroscopy in crystallo validates the identity and oxidation state of the bound metal. The measured subfemtomolar dissociation constant (Kd = 6.41 × 10(-16) M) of DJ-1 for Cu(I) supports the physiological retention of the metal ion. Our results highlight the requirement of a stable homodimer for copper binding by DJ-1. Parkinsonism-linked mutations that weaken homodimer interactions will compromise this capability.
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Affiliation(s)
- M Rhyan Puno
- Department of Molecular and Applied Biosciences, University of Westminster , 115 New Cavendish Street, London W1W 6UW, United Kingdom
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20
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Du X, Li H, Wang X, Liu Q, Ni J, Sun H. Kinetics and thermodynamics of metal binding to the N-terminus of a human copper transporter, hCTR1. Chem Commun (Camb) 2013; 49:9134-6. [PMID: 23962988 DOI: 10.1039/c3cc45360j] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The N-terminus of hCTR1 was demonstrated to bind three Cu(+) ions tightly (log K = 14.92) and reversibly via its Met-rich motifs. Ag(+) binds to the protein with the same stoichiometry but much lower affinities than Cu(+). The protein also coordinates two Cu(2+) ions through its ATCUN motif and His-rich motif with lower affinity. This study provides an insight into the selectivity of the transporter.
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Affiliation(s)
- Xiubo Du
- Department of Chemistry, The University of Hong Kong, Hong Kong, China.
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21
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Abstract
Biological trace metals are needed in small quantities, but used by all living organisms. They are employed in key cellular functions in a variety of biological processes, resulting in the various degree of dependence of organisms on metals. Most effort in the field has been placed on experimental studies of metal utilization pathways and metal-dependent proteins. On the other hand, systemic level analyses of metalloproteomes (or metallomes) have been limited for most metals. In this chapter, we focus on the recent advances in comparative genomics, which provides many insights into evolution and function of metal utilization. These studies suggested that iron and zinc are widely used in biology (presumably by all organisms), whereas some other metals such as copper, molybdenum, nickel, and cobalt, show scattered occurrence in various groups of organisms. For these metals, most user proteins are well characterized and their dependence on a specific element is evolutionarily conserved. We also discuss evolutionary dynamics of the dependence of user proteins on different metals. Overall, comparative genomics analysis of metallomes provides a foundation for the systemic level understanding of metal utilization as well as for investigating the general features, functions, and evolutionary dynamics of metal use in the three domains of life.
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22
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Allen S, Badarau A, Dennison C. The influence of protein folding on the copper affinities of trafficking and target sites. Dalton Trans 2012; 42:3233-9. [PMID: 23169585 DOI: 10.1039/c2dt32166a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The relative influence of protein unfolding on the Cu(I) affinity of trafficking and target sites for copper has been determined. For the copper metallochaperone Atx1 from Synechocystis PCC 6803 (a cyanobacterium), Saccharomyces cerevisiae and humans unfolding in urea results in a decrease in the Cu(I) affinity from (4-5) × 10(17) M(-1) to (1-3) × 10(16) M(-1) at pH 7. The affinities of the unfolded Atx1s are similar to those for CXXC-containing peptides. Partial unfolding, due to the loop 5 His61Lys mutation in Synechocystis Atx1, gives rise to a more limited decrease in Cu(I) affinity. For the copper target protein plastocyanin from Synechocystis, chemical unfolding results in the Cu(I) affinity decreasing by 5-orders of magnitude. This differential influence of protein unfolding on Cu(I) affinity is due to a more complex copper site structure in the target protein, including numerous interactions of non-coordinating residues with ligating amino acids. This second-coordination sphere is much simpler in the Atx1s with the main interaction provided by the loop 5 residue that tunes the Cu(I) affinity by altering the pK(a) of the C-terminal Cys ligand of the CXXC motif. This interaction and others are absent in the unfolded Atx1s and the two Cys ligands have pK(a) values reminiscent of free thiols (>8) resulting in lowered Cu(I) affinities at pH 7. Residues close to the active site of the thiol-disulfide oxidoreductase thioredoxin appear to lower the Cu(I) affinity of its CXXC motif to 3.1 × 10(15) M(-1) at pH 7, presumably to prevent copper binding in vivo. The structure of a copper site, including the number and relative position of ligands in the primary structure and the complexity of the second-coordination sphere, results in dramatically different effects of unfolding on Cu(I) affinity that has important implications for copper homeostasis.
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Affiliation(s)
- Stephen Allen
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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23
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Serventi F, Youard ZA, Murset V, Huwiler S, Bühler D, Richter M, Luchsinger R, Fischer HM, Brogioli R, Niederer M, Hennecke H. Copper starvation-inducible protein for cytochrome oxidase biogenesis in Bradyrhizobium japonicum. J Biol Chem 2012; 287:38812-23. [PMID: 23012364 DOI: 10.1074/jbc.m112.406173] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microarray analysis of Bradyrhizobium japonicum grown under copper limitation uncovered five genes named pcuABCDE, which are co-transcribed and co-regulated as an operon. The predicted gene products are periplasmic proteins (PcuA, PcuC, and PcuD), a TonB-dependent outer membrane receptor (PcuB), and a cytoplasmic membrane-integral protein (PcuE). Homologs of PcuC and PcuE had been discovered in other bacteria, namely PCu(A)C and YcnJ, where they play a role in cytochrome oxidase biogenesis and copper transport, respectively. Deletion of the pcuABCDE operon led to a pleiotropic phenotype, including defects in the aa(3)-type cytochrome oxidase, symbiotic nitrogen fixation, and anoxic nitrate respiration. Complementation analyses revealed that, under our assay conditions, the tested functions depended only on the pcuC gene and not on pcuA, pcuB, pcuD, or pcuE. The B. japonicum genome harbors a second pcuC-like gene (blr7088), which, however, did not functionally replace the mutated pcuC. The PcuC protein was overexpressed in Escherichia coli, purified to homogeneity, and shown to bind Cu(I) with high affinity in a 1:1 stoichiometry. The replacement of His(79), Met(90), His(113), and Met(115) by alanine perturbed copper binding. This corroborates the previously purported role of this protein as a periplasmic copper chaperone for the formation of the Cu(A) center on the aa(3)-type cytochrome oxidase. In addition, we provide evidence that PcuC and the copper chaperone ScoI are important for the symbiotically essential, Cu(A)-free cbb(3)-type cytochrome oxidase specifically in endosymbiotic bacteroids of soybean root nodules, which could explain the symbiosis-defective phenotype of the pcuC and scoI mutants.
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Affiliation(s)
- Fabio Serventi
- Institute of Microbiology, Eidgenössische Technische Hochschule Zürich (ETH Zürich), Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
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24
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Prokaryotic assembly factors for the attachment of flavin to complex II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1827:637-47. [PMID: 22985599 DOI: 10.1016/j.bbabio.2012.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 09/05/2012] [Accepted: 09/07/2012] [Indexed: 01/01/2023]
Abstract
Complex II (also known as Succinate dehydrogenase or Succinate-ubiquinone oxidoreductase) is an important respiratory enzyme that participates in both the tricarboxylic acid cycle and electron transport chain. Complex II consists of four subunits including a catalytic flavoprotein (SdhA), an iron-sulphur subunit (SdhB) and two hydrophobic membrane anchors (SdhC and SdhD). Complex II also contains a number of redox cofactors including haem, Fe-S clusters and FAD, which mediate electron transfer from succinate oxidation to the reduction of the mobile electron carrier ubiquinone. The flavin cofactor FAD is an important redox cofactor found in many proteins that participate in oxidation/reduction reactions. FAD is predominantly bound non-covalently to flavoproteins, with only a small percentage of flavoproteins, such as complex II, binding FAD covalently. Aside from a few examples, the mechanisms of flavin attachment have been a relatively unexplored area. This review will discuss the FAD cofactor and the mechanisms used by flavoproteins to covalently bind FAD. Particular focus is placed on the attachment of FAD to complex II with an emphasis on SdhE (a DUF339/SDH5 protein previously termed YgfY), the first protein identified as an assembly factor for FAD attachment to flavoproteins in prokaryotes. The molecular details of SdhE-dependent flavinylation of complex II are discussed and comparisons are made to known cofactor chaperones. Furthermore, an evolutionary hypothesis is proposed to explain the distribution of SdhE homologues in bacterial and eukaryotic species. Mechanisms for regulating SdhE function and how this may be linked to complex II function in different bacterial species are also discussed. This article is part of a Special Issue entitled: Respiratory complex II: Role in cellular physiology and disease.
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25
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Direct and indirect regulation of the ycnKJI operon involved in copper uptake through two transcriptional repressors, YcnK and CsoR, in Bacillus subtilis. J Bacteriol 2012; 194:5675-87. [PMID: 22904286 DOI: 10.1128/jb.00919-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Northern blot and primer extension analyses revealed that the ycnKJI operon and the ycnL gene of Bacillus subtilis are transcribed from adjacent promoters that are divergently oriented. The ycnK and ycnJ genes encode a DeoR-type transcriptional regulator and a membrane protein involved in copper uptake, respectively. DNA binding experiments showed that the YcnK protein specifically binds to the ycnK-ycnL intergenic region, including a 16-bp direct repeat that is essential for the high binding affinity of YcnK, and that a copper-specific chelator significantly inhibits YcnK's DNA binding. lacZ reporter analysis showed that the ycnK promoter is induced by copper limitation or ycnK disruption. These results are consistent with YcnK functioning as a copper-responsive repressor that derepresses ycnKJI expression under copper limitation. On the other hand, the ycnL promoter was hardly induced by copper limitation, but ycnK disruption resulted in a slight induction of the ycnL promoter, suggesting that YcnK also represses ycnL weakly. Moreover, while the CsoR protein did not bind to the ycnK-ycnL intergenic region, lacZ reporter analysis demonstrated that csoR disruption induces the ycnK promoter only in the presence of intact ycnK and copZA genes. Since the copZA operon is involved in copper export and repressed by CsoR, it appears that the constitutive copZA expression brought by csoR disruption causes intracellular copper depletion, which releases the repression of the ycnKJI operon by YcnK.
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Variations in methanobactin structure influences copper utilization by methane-oxidizing bacteria. Proc Natl Acad Sci U S A 2012; 109:8400-4. [PMID: 22582172 DOI: 10.1073/pnas.1112921109] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Methane-oxidizing bacteria are nature's primary biological mechanism for suppressing atmospheric levels of the second-most important greenhouse gas via methane monooxygenases (MMOs). The copper-containing particulate enzyme is the most widespread and efficient MMO. Under low-copper conditions methane-oxidizing bacteria secrete the small copper-binding peptide methanobactin (mbtin) to acquire copper, but how variations in the structures of mbtins influence copper metabolism and species selection are unknown. Methanobactins have been isolated from Methylocystis strains M and hirsuta CSC1, organisms that can switch to using an iron-containing soluble MMO when copper is limiting, and the nonswitchover Methylocystis rosea. These mbtins are shorter, and have different amino acid compositions, than the characterized mbtin from Methylosinus trichosporium OB3b. A coordinating pyrazinedione ring in the Methylocystis mbtins has little influence on the Cu(I) site structure. The Methylocystis mbtins have a sulfate group that helps stabilize the Cu(I) forms, resulting in affinities of approximately 10(21) M(-1). The Cu(II) affinities vary over three orders of magnitude with reduction potentials covering approximately 250 mV, which may dictate the mechanism of intracellular copper release. Copper uptake and the switchover from using the iron-containing soluble MMO to the copper-containing particulate enzyme is faster when mediated by the native mbtin, suggesting that the amino acid sequence is important for the interaction of mbtins with receptors. The differences in structures and properties of mbtins, and their influence on copper utilization by methane-oxidizing bacteria, have important implications for the ecology and global function of these environmentally vital organisms.
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27
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Click TH, Ponomarev SY, Kaminski GA. Importance of electrostatic polarizability in calculating cysteine acidity constants and copper(I) binding energy of Bacillus subtilis CopZ. J Comput Chem 2012; 33:1142-51. [PMID: 22370900 DOI: 10.1002/jcc.22944] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 12/13/2011] [Accepted: 01/08/2012] [Indexed: 11/09/2022]
Abstract
CopZ is a copper chaperone from Bacillus subtilis. It is an important part of Cu(I) trafficking. We have calculated pK(a) values for the CXXC motif of this protein, which is responsible for the Cu(I) binding, and the Cu(I) binding constants. Polarizable and fixed-charges formalisms were used, and solvation parameters for the both models have been refitted. We had to partially redevelop parameters for the protonated and deprotonated cysteine residues. We have discovered that the polarizable force field (PFF) is qualitatively superior and allows a uniformly better level of energetic results. The PFF pK(a) values for cysteine are within about 0.8-2.8 pH units of the experimental data, while the fixed-charges OPLS formalism yields errors of up to tens of units. The PFF magnitude of the copper binding energy is about 10 kcal/mol or 50% higher than the experimental value, while the using the refitted OPLS parameters leads to an overall positive binding energy, thus predicting no thermodynamically stable complex. At the same time, the agreement of the polarizable S···Cu(I) distances with the experimental results is within 0.08 Å range, and the nonpolarizable calculations lead to an error of about 0.4 Å. Moreover, the accuracy of the PFF has been achieved without any explicit fitting to either pK(a) or CopZ···Cu(I) binding energies. We believe that this makes our polarizable technique a choice method in reproducing protein-copper binding and further supports the notion that explicit treatment of electrostatic polarization is crucial in many biologically relevant studies, especially ion binding and transport.
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Affiliation(s)
- Timothy H Click
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609, USA
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28
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Allen S, Badarau A, Dennison C. Cu(I) affinities of the domain 1 and 3 sites in the human metallochaperone for Cu,Zn-superoxide dismutase. Biochemistry 2012; 51:1439-48. [PMID: 22320662 DOI: 10.1021/bi201370r] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The delivery of copper by the human metallochaperone CCS is a key step in the activation of Cu,Zn-superoxide dismutase (SOD1). CCS is a three-domain protein with Cu(I)-binding CXXC and CXC motifs in domains 1 and 3, respectively. A detailed analysis of the binding of copper to CCS, including variants in which the Cys residues from domains 1 and 3 have been mutated to Ser, and also using separate domain 1 and 3 constructs, demonstrates that CCS is able to bind 1 equiv of Cu(I) in both of these domains. The Cu(I) affinity of domain 1 is approximately 5 × 10(17) M(-1) at pH 7.5, while that of domain 3 is at least 1 order of magnitude weaker. The CXXC site will therefore be preferentially loaded with Cu(I), suggesting that domain 1 plays a role in the acquisition of the metal. The delivery of copper to the target occurs via domain 3 whose structural flexibility and ability to be transiently metalated during copper delivery appear to be more important than the Cu(I) affinity of its CXC motif. The Cu(I) affinity of domain 1 of CCS is comparable to that of HAH1, another cytosolic copper metallochaperone. CCS and HAH1 readily exchange Cu(I), providing a mechanism whereby cross-talk can occur between copper trafficking pathways.
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Affiliation(s)
- Stephen Allen
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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Coordination chemistry of copper proteins: How nature handles a toxic cargo for essential function. J Inorg Biochem 2012; 107:129-43. [DOI: 10.1016/j.jinorgbio.2011.11.024] [Citation(s) in RCA: 232] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/25/2011] [Accepted: 11/15/2011] [Indexed: 01/16/2023]
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30
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Zhou L, Singleton C, Le Brun NE. CopAb, the second N-terminal soluble domain of Bacillus subtilis CopA, dominates the Cu(i)-binding properties of CopAab. Dalton Trans 2012; 41:5939-48. [DOI: 10.1039/c2dt30126a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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31
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Zhou L, Singleton C, Hecht O, Moore GR, Le Brun NE. Cu(I)- and proton-binding properties of the first N-terminal soluble domain of Bacillus subtilis CopA. FEBS J 2011; 279:285-98. [DOI: 10.1111/j.1742-4658.2011.08422.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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32
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Badarau A, Dennison C. Thermodynamics of copper and zinc distribution in the cyanobacterium Synechocystis PCC 6803. Proc Natl Acad Sci U S A 2011; 108:13007-12. [PMID: 21778408 PMCID: PMC3156197 DOI: 10.1073/pnas.1101448108] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Copper is supplied to plastocyanin for photosynthesis and cytochrome c oxidase for respiration in the thylakoids of Synechocystis PCC 6803 by the membrane-bound P-type ATPases CtaA and PacS, and the metallochaperone Atx1. We have determined the Cu(I) affinities of all of the soluble proteins and domains in this pathway. The Cu(I) affinities of the trafficking proteins range from 5 × 10(16) to 5 × 10(17) M(-1) at pH 7.0, consistent with values for homologues. Unusually, Atx1 binds Cu(I) significantly tighter than the metal-binding domains (MBDs) of CtaA and PacS (CtaA(N) and PacS(N)), and equilibrium copper exchange constants of approximately 0.2 are obtained for transfer to the MBDs. Dimerization of Atx1 increases the affinity for Cu(I), but the loop 5 His61 residue has little influence. The MBD of the zinc exporter ZiaA (ZiaA(N)) exhibits an almost identical Cu(I) affinity, and Cu(I) exchange with Atx1, as CtaA(N) and PacS(N), and the relative stabilities of the complexes must enable the metallochaperone to distinguish between the MBDs. The binding of potentially competing zinc to the trafficking proteins has been studied. ZiaA(N) has the highest Zn(II) affinity and thermodynamics could be important for zinc removal from the cell. Plastocyanin has a Cu(I) affinity of 2.6 × 10(17) M(-1), 15-fold tighter than that of the Cu(A) site of cytochrome c oxidase, highlighting the need for specific mechanisms to ensure copper delivery to both of these targets. The narrow range of Cu(I) affinities for the cytoplasmic copper proteins in Synechocystis will facilitate relocation when copper is limiting.
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Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom
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33
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Banci L, Bertini I, Cefaro C, Ciofi-Baffoni S, Gallo A. Functional role of two interhelical disulfide bonds in human Cox17 protein from a structural perspective. J Biol Chem 2011; 286:34382-90. [PMID: 21816817 DOI: 10.1074/jbc.m111.246223] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human Cox17 is the mitochondrial copper chaperone responsible for supplying copper ions, through the assistance of Sco1, Sco2, and Cox11, to cytochrome c oxidase, the terminal enzyme of the mitochondrial energy-transducing respiratory chain. It consists of a coiled coil-helix-coiled coil-helix domain stabilized by two disulfide bonds and binds one copper(I) ion through a Cys-Cys motif. Here, the structures and the backbone mobilities of two Cox17 mutated forms with only one interhelical disulfide bond have been analyzed. It appears that the inner disulfide bond (formed by Cys-36 and Cys-45) stabilizes interhelical hydrophobic interactions, providing a structure with essentially the same structural dynamic properties of the mature Cox17 state. On the contrary, the external disulfide bond (formed by Cys-26 and Cys-55) generates a conformationally flexible α-helical protein, indicating that it is not able to stabilize interhelical packing contacts, but is important for structurally organizing the copper-binding site region.
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Affiliation(s)
- Lucia Banci
- Magnetic Resonance Center Centro Risonanze Magnetiche and Department of Chemistry, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Florence, Italy
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34
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Ponomarev SY, Click TH, Kaminski GA. Electrostatic polarization is crucial in reproducing Cu(I) interaction energies and hydration. J Phys Chem B 2011; 115:10079-85. [PMID: 21761909 DOI: 10.1021/jp2051933] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have explored the suitability of fixed-charges and polarizable force fields for modeling interactions of the monovalent Cu(I) ion. Parameters for this ion have been tested and refitted within the fixed-charges OPLS-AA and polarizable force field (PFF) frameworks. While this ion plays an important role in many protein interactions, the attention to it in developing empirical force fields is limited. Our PFF parameters for the copper ion worked very well for the Cu(I) interactions with water, while both the original OPLS2005 and our refitted OPLS versions moderately underestimated the copper-water interaction energy. However, the greatest problem in using the nonpolarizable fixed-charges OPLS force field was observed while calculating interaction energies and distances for Cu(I)-benzene complexes. The OPLS2005 model underestimates the interaction energy by a factor of 4. Refitting the OPLS parameters reduced this underestimation to a factor of 2.2-2.4, but only at a cost of distorting the complex geometry. At the same time, the polarizable calculations had an error of about 4%. Moreover, we then used the PFF and nonpolarizable refitted OPLS models for finding free energy of hydration for copper ion via molecular dynamics simulations. While the OPLS calculations lead to a 22% error in the solvation energy, the PFF result was off by only 1.8%. This was achieved with no refitting of the parameters but simply by employing the model developed for the Cu(I) interaction with a single water molecule. We believe that the presented results not only lead to a conclusion about a qualitatively greater suitability of polarizable force fields for simulating molecular interactions with ions but also attest to the excellent level of transferability of PFF parameters.
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Affiliation(s)
- Sergei Y Ponomarev
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
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35
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Schmidt A, Hagen M, Schütze E, Schmidt A, Kothe E. In silico prediction of potential metallothioneins and metallohistins in actinobacteria. J Basic Microbiol 2011; 50:562-9. [PMID: 21077111 DOI: 10.1002/jobm.201000055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Metallothioneins and metallohistins are short peptides with a high cysteine and/or histidine content able to coordinate metals intracellularly, thereby increasing the tolerance against elevated concentrations of metals. Because of their features, they can be detected by in silico prediction from proteomes annotated from sequenced genomes. Here, we analyzed 73 sequenced actinobacterial genomes for peptides (≤ 100 amino acids) with a high content of cysteine and histidine (≥ 15%) and identified 103 putative metallothioneins and metallohistins. For 45 of these peptides, we found similarities to metal binding protein domains, including zinc fingers, heavy metal transporters or eukaryotic metallothioneins, which can serve as proof-of-principle in underscoring a potential function as metal binding peptides. An evolutionary origin from metal containing domains of enzymes is discussed and metallohistins not containing cysteine are described for the first time for bacteria.
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Affiliation(s)
- Andre Schmidt
- Microbial Phytopathology, Institute of Microbiology, Faculty of Biology and Pharmacy, Friedrich-Schiller-University, Jena, Germany
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36
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Badarau A, Dennison C. Copper Trafficking Mechanism of CXXC-Containing Domains: Insight from the pH-Dependence of Their Cu(I) Affinities. J Am Chem Soc 2011; 133:2983-8. [DOI: 10.1021/ja1091547] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical
School, Newcastle University, Newcastle
upon Tyne, NE2 4HH, U.K
| | - Christopher Dennison
- Institute for Cell and Molecular Biosciences, Medical
School, Newcastle University, Newcastle
upon Tyne, NE2 4HH, U.K
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37
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Xiao Z, Brose J, Schimo S, Ackland SM, La Fontaine S, Wedd AG. Unification of the copper(I) binding affinities of the metallo-chaperones Atx1, Atox1, and related proteins: detection probes and affinity standards. J Biol Chem 2011; 286:11047-55. [PMID: 21258123 DOI: 10.1074/jbc.m110.213074] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Literature estimates of metal-protein affinities are widely scattered for many systems, as highlighted by the class of metallo-chaperone proteins, which includes human Atox1. The discrepancies may be attributed to unreliable detection probes and/or inconsistent affinity standards. In this study, application of the four Cu(I) ligand probes bicinchoninate, bathocuproine disulfonate, dithiothreitol (Dtt), and glutathione (GSH) is reviewed, and their Cu(I) affinities are re-estimated and unified. Excess bicinchoninate or bathocuproine disulfonate reacts with Cu(I) to yield distinct 1:2 chromatophoric complexes [Cu(I)L(2)](3-) with formation constants β(2) = 10(17.2) and 10(19.8) m(-2), respectively. These constants do not depend on proton concentration for pH ≥7.0. Consequently, they are a pair of complementary and stable probes capable of detecting free Cu(+) concentrations from 10(-12) to 10(-19) m. Dtt binds Cu(I) with K(D) ∼10(-15) m at pH 7, but it is air-sensitive, and its Cu(I) affinity varies with pH. The Cu(I) binding properties of Atox1 and related proteins (including the fifth and sixth domains at the N terminus of the Wilson protein ATP7B) were assessed with these probes. The results demonstrate the following: (i) their use permits the stoichiometry of high affinity Cu(I) binding and the individual quantitative affinities (K(D) values) to be determined reliably via noncompetitive and competitive reactions, respectively; (ii) the scattered literature values are unified by using reliable probes on a unified scale; and (iii) Atox1-type proteins bind Cu(I) with sub-femtomolar affinities, consistent with tight control of labile Cu(+) concentrations in living cells.
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Affiliation(s)
- Zhiguang Xiao
- School of Chemistry and Bio21 Institute, University of Melbourne, Victoria, Australia.
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38
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Rubino JT, Chenkin MP, Keller M, Riggs-Gelasco P, Franz KJ. A comparison of methionine, histidine and cysteine in copper(I)-binding peptides reveals differences relevant to copper uptake by organisms in diverse environments. Metallomics 2010; 3:61-73. [PMID: 21305075 DOI: 10.1039/c0mt00044b] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The N-terminal, extracellular regions of eukaryotic high affinity copper transport (Ctr) proteins vary in composition of the Cu(i) binding amino acids: methionine, histidine, and cysteine. To examine why certain amino acids are exploited over others in Ctrs from different organisms, the relative Cu(i) binding affinity and the dependence of binding on pH were examined for 3 peptides of the sequence MG(2)XG(2)MK, where X is either Met, His, or Cys. Cu(i) affinity was examined using an ascorbic acid oxidation assay, an electrospray ionization mass spectrometry technique, and spectrophotometric titration with a competitive Cu(i) chelator. The relative affinities of the peptides with Cu(i) reveal a trend whereby Cys > His > Met at pH 7.4 and Cys > Met > His at pH 4.5. Ligand geometry and metric parameters were determined with X-ray absorption spectroscopy. Susceptibility of the peptides to oxidation by hydrogen peroxide and copper-catalyzed oxidative conditions was evaluated by mass spectrometry. These results support hypotheses as to why certain Cu(i) binding amino acids are preferred over others in proteins expressed at different pH and exposed to oxidative environments. The results also have implications for interpreting site-directed mutagenesis studies aimed at identifying copper binding amino acids in copper trafficking proteins.
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Affiliation(s)
- Jeffrey T Rubino
- Department of Chemistry, Duke University, P.O. Box 90346, Durham, NC 27708-0346, USA
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39
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Badarau A, Firbank SJ, McCarthy AA, Banfield MJ, Dennison C. Visualizing the metal-binding versatility of copper trafficking sites . Biochemistry 2010; 49:7798-810. [PMID: 20726513 DOI: 10.1021/bi101064w] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular systems have evolved to permit the safe delivery of copper. Despite extensive studies, many copper site structures involved in copper homeostasis, even for the well-studied metallochaperone Atx1, remain unresolved. Cyanobacteria import copper to their thylakoid compartments for use in photosynthesis and respiration and possess an Atx1 that we show can adopt multiple oligomeric states when metalated, capable of binding up to four copper ions. Two-copper- and four-copper-loaded dimers exist in solution at low micromolar concentrations, and head-to-head and side-to-side arrangements, respectively, can be crystallized, with the latter binding a [Cu(4){mu(2)-S(gamma)(Cys)}(4)Cl(2)](2-) cluster. The His61Tyr mutation on loop 5 weakens head-to-head dimerization, yet a side-to-side dimer binding a similar cluster as in the wild-type protein, but with phenolate coordination, is present. The cognate metal-binding domains (MBDs) of the P-type ATPases CtaA and PacS, which are proposed to donate copper to and accept copper from Atx1, respectively, are monomeric in the presence of copper. The structure of the MBD of Cu(I)-PacS shows a crystallographic trimer arrangement around a [Cu(3){mu(2)-S(gamma)(Cys)}(3){S(gamma)(Cys)}(3)](2-) cluster that is very similar to that found for an alternate form of the His61Tyr Atx1 mutant. Copper transfer from the MBD of CtaA to Atx1 is favorable, but delivery from Atx1 to the MBD of PacS is strongly dependent upon the dimeric form of Atx1. A copper-induced switch in Atx1 dimer structure may have a regulatory role with cluster formation helping to buffer copper.
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Affiliation(s)
- Adriana Badarau
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
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40
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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41
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Abstract
A key property of metallo-proteins and -enzymes is the affinity of metal ion M for protein ligand P as defined by the dissociation constant KD = [M][P]/[MP]. Its accurate determination is essential for a quantitative understanding of metal selection and speciation. However, the surfaces of proteins are defined by the sidechains of amino acids and so abound in good metal ligands (e.g., imidazole of histidine,thiol of cysteine, carboxylate of aspartic and glutamic acids, etc.). Consequently, adventitious binding of metal ions to protein surfaces is common with KD values > or = 10(-6) M. On the other hand, transport proteins responsible for 'chaperoning' essential metals to their cellular destinations appear to bind the metal ions selectively (KD < 10(-7) M, both for speciation and to minimise the toxic effects of 'free' metal ions. These ions are normally bound with still higher affinities at their ultimate destinations (the active sites of metallo-proteins and -enzymes). This review surveys possible approaches to estimation of these dissociation constants and pinpoints the various problems associated with each approach.
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Affiliation(s)
- Zhiguang Xiao
- University of Melbourne, Parkville, Victoria, Australia.
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42
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Robinson NJ, Winge DR. Copper metallochaperones. Annu Rev Biochem 2010. [PMID: 20205585 DOI: 10.1146/annurev-biochem-030409-143539]+[] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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43
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Abstract
The current state of knowledge on how copper metallochaperones support the maturation of cuproproteins is reviewed. Copper is needed within mitochondria to supply the Cu(A) and intramembrane Cu(B) sites of cytochrome oxidase, within the trans-Golgi network to supply secreted cuproproteins and within the cytosol to supply superoxide dismutase 1 (Sod1). Subpopulations of copper-zinc superoxide dismutase also localize to mitochondria, the secretory system, the nucleus and, in plants, the chloroplast, which also requires copper for plastocyanin. Prokaryotic cuproproteins are found in the cell membrane and in the periplasm of gram-negative bacteria. Cu(I) and Cu(II) form tight complexes with organic molecules and drive redox chemistry, which unrestrained would be destructive. Copper metallochaperones assist copper in reaching vital destinations without inflicting damage or becoming trapped in adventitious binding sites. Copper ions are specifically released from copper metallochaperones upon contact with their cognate cuproproteins and metal transfer is thought to proceed by ligand substitution.
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Affiliation(s)
- Nigel J Robinson
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, NE2 4HH, United Kingdom.
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44
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Djoko KY, Chong LX, Wedd AG, Xiao Z. Reaction Mechanisms of the Multicopper Oxidase CueO from Escherichia coli Support Its Functional Role as a Cuprous Oxidase. J Am Chem Soc 2010; 132:2005-15. [DOI: 10.1021/ja9091903] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karrera Y. Djoko
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Lee Xin Chong
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Anthony G. Wedd
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Zhiguang Xiao
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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45
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Mechanistic insights into Cu(I) cluster transfer between the chaperone CopZ and its cognate Cu(I)-transporting P-type ATPase, CopA. Biochem J 2009; 424:347-56. [PMID: 19751213 DOI: 10.1042/bj20091079] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Multinuclear Cu(I) clusters are common in nature, but little is known about their formation or transfer between proteins. CopZ and CopA from Bacillus subtilis, which are involved in a copper-efflux pathway, both readily accommodate multinuclear Cu(I) clusters. Using the luminescence properties of a multinuclear Cu(I)-bound form of the two N-terminal soluble domains of CopA (CopAab) we have investigated the thermodynamic and kinetic properties of cluster formation and loss. We demonstrate that Cu(I)-bound forms of dimeric CopZ containing more than one Cu(I) per CopZ monomer can transfer Cu(I) to apo-CopAab, leading to the formation of luminescent dimeric CopAab. Kinetic studies demonstrated that transfer is a first-order process and that the rate-determining steps for transfer from CopZ to CopAab and vice versa are different processes. The rate of formation of luminescent CopAab via transfer of Cu(I) from CopZ was more rapid than that observed when Cu(I) was added 'directly' from solution or in complex with a cysteine variant of CopZ, indicating that transfer occurs via a transient protein-protein complex. Such a complex would probably require the interaction of at least one domain of CopAab with the CopZ dimer. Insight into how such a complex might form is provided by the high resolution crystal structure of Cu3(CopZ)3, a thus far unique trimeric form of CopZ containing a trinuclear Cu(I) cluster. Modelling studies showed that one of the CopZ monomers can be substituted for either domain of CopAab, resulting in a heterotrimer, thus providing a model for a 'trapped' copper exchange complex.
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46
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Zimmermann M, Clarke O, Gulbis JM, Keizer DW, Jarvis RS, Cobbett CS, Hinds MG, Xiao Z, Wedd AG. Metal Binding Affinities of Arabidopsis Zinc and Copper Transporters: Selectivities Match the Relative, but Not the Absolute, Affinities of their Amino-Terminal Domains,. Biochemistry 2009; 48:11640-54. [DOI: 10.1021/bi901573b] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Oliver Clarke
- Department of Medical Biology
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Jacqui M. Gulbis
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | | | | | | | - Mark G. Hinds
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Zhiguang Xiao
- School of Chemistry
- Bio21 Molecular Science and Biotechnology Institute
| | - Anthony G. Wedd
- School of Chemistry
- Bio21 Molecular Science and Biotechnology Institute
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47
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Chong LX, Ash MR, Maher MJ, Hinds MG, Xiao Z, Wedd AG. Unprecedented binding cooperativity between Cu(I) and Cu(II) in the copper resistance protein CopK from Cupriavidus metallidurans CH34: implications from structural studies by NMR spectroscopy and X-ray crystallography. J Am Chem Soc 2009; 131:3549-64. [PMID: 19236095 DOI: 10.1021/ja807354z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The bacterium Cupriavidus metallidurans CH34 is resistant to high environmental concentrations of many metal ions, including copper. This ability arises primarily from the presence of a large plasmid pMOL30 which includes a cluster of 19 cop genes that respond to copper. One of the protein products CopK is induced at high levels and is expressed to the periplasm as a small soluble protein (8.3 kDa). Apo-CopK associates in solution to form a dimer (K(D) approximately 10(-5) M) whose structure was defined by NMR and X-ray crystallography. The individual molecules feature two antiparallel beta-sheets arranged in a sandwich-like structure and interact through C-terminal beta-strands. It binds Cu(II) with low affinity (K(D)(Cu(II)) > 10(-6) M) but Cu(I) with high affinity (K(D)(Cu(I)) = 2 x 10(-11) M). Cu(I)-CopK was also a dimer in the solid state and featured a distorted tetrahedral site Cu(I)(S-Met)(3)(NCS). The isothiocyanato ligand originated from the crystallization solution. Binding of Cu(I) or Ag(I), but not of Cu(II), favored the monomeric form in solution. While Ag(I)-CopK was stable as isolated, Cu(I)-CopK was moderately air-sensitive due to a strong binding cooperativity between Cu(I) and Cu(II). This was documented by determination of the Cu(I) and Cu(II) binding affinities in the presence of the other ion: K(D)(Cu(I)) = 2 x 10(-13) M and K(D)(Cu(II)) = 3 x 10(-12) M, that is, binding of Cu(II) increased the affinity for Cu(I) by a factor of approximately 10(2) and binding of Cu(I) increased the affinity for Cu(II) by a factor of at least 10(6). Stable forms of both Cu(I)Cu(II)-CopK and Ag(I)Cu(II)-CopK were isolated readily. Consistent with this unprecedented copper binding chemistry, NMR spectroscopy detected three distinct forms: apo-CopK, Cu(I)-CopK and Cu(I)Cu(II)-CopK that do not exchange on the NMR time scale. This information provides a valuable guide to the role of CopK in copper resistance.
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Affiliation(s)
- Lee Xin Chong
- School of Chemistry and, Biomolecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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48
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Zhang Y, Gladyshev VN. Comparative Genomics of Trace Elements: Emerging Dynamic View of Trace Element Utilization and Function. Chem Rev 2009; 109:4828-61. [DOI: 10.1021/cr800557s] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Yan Zhang
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
| | - Vadim N. Gladyshev
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664
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49
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Rodriguez-Granillo A, Wittung-Stafshede P. Tuning of Copper-Loop Flexibility in Bacillus subtilis CopZ Copper Chaperone: Role of Conserved Residues. J Phys Chem B 2009; 113:1919-32. [DOI: 10.1021/jp807594q] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Agustina Rodriguez-Granillo
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251, and Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
| | - Pernilla Wittung-Stafshede
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251, and Department of Chemistry, Umeå University, 901 87 Umeå, Sweden
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Singleton C, Le Brun NE. The N-terminal soluble domains of Bacillus subtilis CopA exhibit a high affinity and capacity for Cu(i) ions. Dalton Trans 2009:688-96. [DOI: 10.1039/b810412c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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