1
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Zhang Y, Su D, Dzikovski B, Majer SH, Coleman R, Chandrasekaran S, Fenwick MK, Crane BR, Lancaster KM, Freed JH, Lin H. Dph3 Enables Aerobic Diphthamide Biosynthesis by Donating One Iron Atom to Transform a [3Fe-4S] to a [4Fe-4S] Cluster in Dph1-Dph2. J Am Chem Soc 2021; 143:9314-9319. [PMID: 34154323 PMCID: PMC8251694 DOI: 10.1021/jacs.1c03956] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
All radical S-adenosylmethionine (radical-SAM) enzymes, including the noncanonical radical-SAM enzyme diphthamide biosynthetic enzyme Dph1-Dph2, require at least one [4Fe-4S](Cys)3 cluster for activity. It is well-known in the radical-SAM enzyme community that the [4Fe-4S](Cys)3 cluster is extremely air-sensitive and requires strict anaerobic conditions to reconstitute activity in vitro. Thus, how such enzymes function in vivo in the presence of oxygen in aerobic organisms is an interesting question. Working on yeast Dph1-Dph2, we found that consistent with the known oxygen sensitivity, the [4Fe-4S] cluster is easily degraded into a [3Fe-4S] cluster. Remarkably, the small iron-containing protein Dph3 donates one Fe atom to convert the [3Fe-4S] cluster in Dph1-Dph2 to a functional [4Fe-4S] cluster during the radical-SAM enzyme catalytic cycle. This mechanism to maintain radical-SAM enzyme activity in aerobic environments is likely general, and Dph3-like proteins may exist to keep other radical-SAM enzymes functional in aerobic environments.
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Affiliation(s)
- Yugang Zhang
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Dan Su
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Boris Dzikovski
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Sean H Majer
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Rachael Coleman
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Siddarth Chandrasekaran
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Michael K Fenwick
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Brian R Crane
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Kyle M Lancaster
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Jack H Freed
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.,Howard Hughes Medical Institute, Cornell University, Ithaca, New York 14853, United States
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2
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Boudalis AK. Half-Integer Spin Triangles: Old Dogs, New Tricks. Chemistry 2021; 27:7022-7042. [PMID: 33336864 DOI: 10.1002/chem.202004919] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/14/2020] [Indexed: 11/06/2022]
Abstract
Spin triangles, that is, triangular complexes of half-integer spins, are the oldest molecular nanomagnets (MNMs). Their magnetic properties have been studied long before molecular magnetism was delineated as a research field. This Review presents the history of their study, with references to the parallel development of new experimental investigations and new theoretical ideas used for their interpretation. It then presents an indicative list of spin-triangle families to illustrate their chemical diversity. Finally, it makes reference to recent developments in terms of theoretical ideas and new phenomena, as well as to the relevance of spin triangles to spintronic devices and new physics.
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Affiliation(s)
- Athanassios K Boudalis
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), UMR 7504, Université de Strasbourg, CNRS, 67000, Strasbourg, France.,Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra), Université de Strasbourg, 4 rue Blaise Pascal, CS 90032, 67081, Strasbourg, France
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3
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Luu Trinh MD, Miyazaki D, Ono S, Nomata J, Kono M, Mino H, Niwa T, Okegawa Y, Motohashi K, Taguchi H, Hisabori T, Masuda S. The evolutionary conserved iron-sulfur protein TCR controls P700 oxidation in photosystem I. iScience 2021; 24:102059. [PMID: 33554065 PMCID: PMC7848650 DOI: 10.1016/j.isci.2021.102059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 12/08/2020] [Accepted: 01/08/2021] [Indexed: 11/21/2022] Open
Abstract
In natural habitats, plants have developed sophisticated regulatory mechanisms to optimize the photosynthetic electron transfer rate at the maximum efficiency and cope with the changing environments. Maintaining proper P700 oxidation at photosystem I (PSI) is the common denominator for most regulatory processes of photosynthetic electron transfers. However, the molecular complexes and cofactors involved in these processes and their function(s) have not been fully clarified. Here, we identified a redox-active chloroplast protein, the triplet-cysteine repeat protein (TCR). TCR shared similar expression profiles with known photosynthetic regulators and contained two triplet-cysteine motifs (CxxxCxxxC). Biochemical analysis indicated that TCR localizes in chloroplasts and has a [3Fe-4S] cluster. Loss of TCR limited the electron sink downstream of PSI during dark-to-light transition. Arabidopsis pgr5-tcr double mutant reduced growth significantly and showed unusual oxidation and reduction of plastoquinone pool. These results indicated that TCR is involved in electron flow(s) downstream of PSI, contributing to P700 oxidation. P700 oxidation at photosystem I is important for regulation of photosynthesis TCR is a redox active chloroplast protein harboring a 3Fe-4S iron-sulfur cluster TCR controls electron flow around photosystem I, contributing to P700 oxidation
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Affiliation(s)
- Mai Duy Luu Trinh
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Daichi Miyazaki
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Sumire Ono
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Jiro Nomata
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Masaru Kono
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hiroyuki Mino
- Division of Materials Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
| | - Tatsuya Niwa
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Yuki Okegawa
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Ken Motohashi
- Department of Frontier Life Sciences, Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan
| | - Hideki Taguchi
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Toru Hisabori
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Shinji Masuda
- Department of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
- Corresponding author
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4
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Shigi N, Horitani M, Miyauchi K, Suzuki T, Kuroki M. An ancient type of MnmA protein is an iron-sulfur cluster-dependent sulfurtransferase for tRNA anticodons. RNA (NEW YORK, N.Y.) 2020; 26:240-250. [PMID: 31801798 PMCID: PMC7025502 DOI: 10.1261/rna.072066.119] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/01/2019] [Indexed: 05/27/2023]
Abstract
Transfer RNA (tRNA) is an adaptor molecule indispensable for assigning amino acids to codons on mRNA during protein synthesis. 2-thiouridine (s2U) derivatives in the anticodons (position 34) of tRNAs for glutamate, glutamine, and lysine are post-transcriptional modifications essential for precise and efficient codon recognition in all organisms. s2U34 is introduced either by (i) bacterial MnmA/eukaryote mitochondrial Mtu1 or (ii) eukaryote cytosolic Ncs6/archaeal NcsA, and the latter enzymes possess iron-sulfur (Fe-S) cluster. Here, we report the identification of novel-type MnmA homologs containing three conserved Cys residues, which could support Fe-S cluster binding and catalysis, in a broad range of bacteria, including thermophiles, Cyanobacteria, Mycobacteria, Actinomyces, Clostridium, and Helicobacter Using EPR spectroscopy, we revealed that Thermus thermophilus MnmA (TtMnmA) contains an oxygen-sensitive [4Fe-4S]-type cluster. Efficient in vitro formation of s2U34 in tRNALys and tRNAGln by holo-TtMnmA occurred only under anaerobic conditions. Mutational analysis of TtMnmA suggested that the Fe-S cluster is coordinated by the three conserved Cys residues (Cys105, Cys108, and Cys200), and is essential for its activity. Evolutionary scenarios for the sulfurtransferases, including the Fe-S cluster containing Ncs6/NcsA s2U thiouridylases and several distantly related sulfurtransferases, are proposed.
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Affiliation(s)
- Naoki Shigi
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Masaki Horitani
- Faculty of Agriculture, Department of Applied Biochemistry and Food Science, Saga University, 1 Honjo-machi, Saga 840-8502, Japan
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Misao Kuroki
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
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5
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Robert J, Parizel N, Turek P, Boudalis AK. Relevance of Dzyaloshinskii–Moriya spectral broadenings in promoting spin decoherence: a comparative pulsed-EPR study of two structurally related iron(iii) and chromium(iii) spin-triangle molecular qubits. Phys Chem Chem Phys 2019; 21:19575-19584. [DOI: 10.1039/c9cp03422f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two related iron(iii) and chromium(iii) spin-triangle molecular qubits show coherent driving of their spins, and decoherence that is not significantly affected by Dzyaloshikskii–Moriya spectral broadenings.
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Affiliation(s)
- Jérôme Robert
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra)
- Université de Strasbourg
- F-67081 Strasbourg
- France
- Sorbonne Université
| | - Nathalie Parizel
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra)
- Université de Strasbourg
- F-67081 Strasbourg
- France
| | - Philippe Turek
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra)
- Université de Strasbourg
- F-67081 Strasbourg
- France
| | - Athanassios K. Boudalis
- Institut de Chimie de Strasbourg (UMR 7177, CNRS-Unistra)
- Université de Strasbourg
- F-67081 Strasbourg
- France
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6
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de Pádua RA, Kia AM, Costa-Filho AJ, Wilkinson SR, Nonato MC. Characterisation of the fumarate hydratase repertoire in Trypanosoma cruzi. Int J Biol Macromol 2017; 102:42-51. [DOI: 10.1016/j.ijbiomac.2017.03.099] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 03/17/2017] [Accepted: 03/18/2017] [Indexed: 11/16/2022]
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7
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Shepard EM, Byer AS, Betz JN, Peters JW, Broderick JB. A Redox Active [2Fe-2S] Cluster on the Hydrogenase Maturase HydF. Biochemistry 2016; 55:3514-27. [PMID: 27232385 DOI: 10.1021/acs.biochem.6b00528] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
[FeFe]-hydrogenases are nature's most prolific hydrogen catalysts, excelling at facilely interconverting H2 and protons. The catalytic core common to all [FeFe]-hydrogenases is a complex metallocofactor, referred to as the H-cluster, which is composed of a standard [4Fe-4S] cluster linked through a bridging thiolate to a 2Fe subcluster harboring dithiomethylamine, carbon monoxide, and cyanide ligands. This 2Fe subcluster is synthesized and inserted into [FeFe]-hydrogenase by three maturase enzymes denoted HydE, HydF, and HydG. HydE and HydG are radical S-adenosylmethionine enzymes and synthesize the nonprotein ligands of the H-cluster. HydF is a GTPase that functions as a scaffold or carrier for 2Fe subcluster production. Herein, we utilize UV-visible, circular dichroism, and electron paramagnetic resonance spectroscopic studies to establish the existence of redox active [4Fe-4S] and [2Fe-2S] clusters bound to HydF. We have used spectroelectrochemical titrations to assign iron-sulfur cluster midpoint potentials, have shown that HydF purifies with a reduced [2Fe-2S] cluster in the absence of exogenous reducing agents, and have tracked iron-sulfur cluster spectroscopic changes with quaternary structural perturbations. Our results provide an important foundation for understanding the maturation process by defining the iron-sulfur cluster content of HydF prior to its interaction with HydE and HydG. We speculate that the [2Fe-2S] cluster of HydF either acts as a placeholder for HydG-derived Fe(CO)2CN species or serves as a scaffold for 2Fe subcluster assembly.
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Affiliation(s)
- Eric M Shepard
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Amanda S Byer
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Jeremiah N Betz
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - John W Peters
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
| | - Joan B Broderick
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59717, United States
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8
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Chrisman MA, Baum RR, Grabo JE, Krause JA, Tierney DL, Baldwin MJ. Structure, spectroscopy, stability, and bridge exchange in the M3O4 incomplete-cubane complexes, [M(III)3(Sal-AHA)3(μ-OR)]− (M = Fe, Ga). Polyhedron 2015. [DOI: 10.1016/j.poly.2015.07.069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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9
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Biochemical similarities and differences between the catalytic [4Fe-4S] cluster containing fumarases FumA and FumB from Escherichia coli. PLoS One 2013; 8:e55549. [PMID: 23405168 PMCID: PMC3565967 DOI: 10.1371/journal.pone.0055549] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 01/02/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The highly homologous [4Fe-4S] containing fumarases FumA and FumB, sharing 90% amino acid sequence identity, from Escherichia coli are differentially regulated, which suggests a difference in their physiological function. The ratio of FumB over FumA expression levels increases by one to two orders of magnitude upon change from aerobic to anaerobic growth conditions. METHODOLOGY/PRINCIPAL FINDINGS To understand this difference in terms of structure-function relations, catalytic and thermodynamic properties were determined for the two enzymes obtained from homologous overexpression systems. FumA and FumB are essentially identical in their Michaelis-Menten kinetics of the reversible fumarate to L-malate conversion; however, FumB has a significantly greater catalytic efficiency for the conversion of D-tartrate to oxaloacetate consistent with the requirement of the fumB gene for growth on D-tartrate. Reduction potentials of the [4Fe-4S](2+) Lewis acid active centre were determined in mediated bulk titrations in the presence of added substrate and were found to be approximately -290 mV for both FumA and FumB. CONCLUSIONS/SIGNIFICANCE This study contradicts previously published claims that FumA and FumB exhibit different catalytic preferences for the natural substrates L-malate and fumarate. FumA and FumB differ significantly only in the catalytic efficiency for the conversion of D-tartrate, a supposedly non-natural substrate. The reduction potential of the substrate-bound [4Fe-4S] active centre is, contrary to previously reported values, close to the cellular redox potential.
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10
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Ossa D, Oliveira R, Murakami M, Vicentini R, Costa-Filho A, Alexandrino F, Ottoboni L, Garcia O. Expression, purification and spectroscopic analysis of an HdrC: An iron–sulfur cluster-containing protein from Acidithiobacillus ferrooxidans. Process Biochem 2011. [DOI: 10.1016/j.procbio.2011.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Sanakis Y, Pissas M, Krzystek J, Telser J, Raptis RG. Spin relaxation in a ferromagnetically coupled triangular Cu3 complex. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.05.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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12
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van Vugt-Lussenburg BMA, van der Weel L, Hagen WR, Hagedoorn PL. Identification of two [4Fe-4S]-cluster-containing hydro-lyases from Pyrococcus furiosus. MICROBIOLOGY-SGM 2009; 155:3015-3020. [PMID: 19520720 DOI: 10.1099/mic.0.030320-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The hyperthermophilic archaeon Pyrococcus furiosus is a strict anaerobe. It is therefore not expected to use the oxidative tricarboxylic acid (TCA) cycle for energy transduction. Nonetheless, its genome encodes more putative TCA cycle enzymes than the closely related Pyrococcus horikoshii and Pyrococcus abyssi, including an aconitase (PF0201). Furthermore, a two-subunit fumarase (PF1755 and PF1754) is encoded on the Pyr. furiosus genome. In the present study, these three genes were heterologously overexpressed in Escherichia coli to enable characterization of the enzymes. PF1755 and PF1754 were shown to form a [4Fe-4S]-cluster-containing heterodimeric enzyme, able to catalyse the reversible hydratation of fumarate. The aconitase PF0201 also contained an Fe-S cluster, and catalysed the conversion from citrate to isocitrate. The fumarase belongs to the class of two-subunit, [4Fe-4S]-cluster-containing fumarate hydratases exemplified by MmcBC from Pelotomaculum thermopropionicum; the aconitase belongs to the aconitase A family. Aconitase probably plays a role in amino acid synthesis when the organism grows on carbohydrates. However, the function of the seemingly metabolically isolated fumarase in Pyr. furiosus has yet to be established.
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Affiliation(s)
| | - Laura van der Weel
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Wilfred R Hagen
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
| | - Peter-Leon Hagedoorn
- Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands
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13
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Mitrikas G, Sanakis Y, Raptopoulou CP, Kordas G, Papavassiliou G. Electron spin–lattice and spin–spin relaxation study of a trinuclear iron(iii) complex and its relevance in quantum computing. Phys Chem Chem Phys 2008; 10:743-8. [DOI: 10.1039/b711056a] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Jensen KP. Computational studies of modified [Fe3S4] clusters: Why iron is optimal. J Inorg Biochem 2008; 102:87-100. [PMID: 17723245 DOI: 10.1016/j.jinorgbio.2007.07.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2007] [Revised: 07/08/2007] [Accepted: 07/17/2007] [Indexed: 10/23/2022]
Abstract
This work reports density functional computations of metal-substituted models of biological [Fe3S4] clusters in oxidation states [MFe2S4](+/0/-1) (M=Mn, Fe, Co, Ni, Cu, Zn, and Mo). Geometry optimization with a dielectric screening model is shown to provide a substantial improvement in structure, compared to earlier used standard procedures. The error for average Fe-S bonds decreased from 0.038A to 0.016A with this procedure. Four density functionals were compared, B3LYP, BP86, TPSS, and TPSSh. B3LYP and to a lesser extent TPSSh energies were inconsistent with experiment for the oxidized [Fe3S4]+ cluster. BP86 (and to a slightly lesser extent TPSS) was within expected theoretical and experimental uncertainties for all oxidation states, the only qualitative error being 5kJ/mol in favor of the M(S)=3/2 configuration for the [Fe3S4]+ cluster, so BP86 was used for quantitative results. Computed reorganization energies and reduction potentials point directly towards the [Fe3S4] cluster as the superior choice of electron carrier, with the [ZnFe2S4] cluster a close second. In addition, partially and fully Mo-substituted clusters were investigated and found to have very low reorganization energies but too negative reduction potentials. The results provide a direct rationale why any substitution weakens the cluster as an electron carrier, and thus why the [Fe3S4] composition is optimal in the biological clusters.
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Affiliation(s)
- Kasper P Jensen
- Technical University of Denmark, Department of Chemistry, Building 207, 2800 Kgs. Lyngby, DK, Denmark.
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15
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Elsaesser C, Brecht M, Bittl R. Treatment of spin-coupled metal-centres in pulsed electron-electron double-resonance experiments. Biochem Soc Trans 2005; 33:15-9. [PMID: 15667252 DOI: 10.1042/bst0330015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In applications of ELDOR (electron-electron double-resonance) spectroscopy to metal centres, significant g-anisotropy and spin-coupling within multinuclear clusters have to be considered. We show the difficulties and the advantages arising from these effects.
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Affiliation(s)
- C Elsaesser
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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16
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Kulik LV, Lubitz W, Messinger J. Electron Spin−Lattice Relaxation of the S0 State of the Oxygen-Evolving Complex in Photosystem II and of Dinuclear Manganese Model Complexes. Biochemistry 2005; 44:9368-74. [PMID: 15982003 DOI: 10.1021/bi050411y] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The temperature dependence of the electron spin-lattice relaxation time T1 was measured for the S0 state of the oxygen-evolving complex (OEC) in photosystem II and for two dinuclear manganese model complexes by pulse EPR using the inversion-recovery method. For [Mn(III)Mn(IV)(mu-O)2 bipy4]ClO4, the Raman relaxation process dominates at temperatures below 50 K. In contrast, Orbach type relaxation was found for [Mn(II)Mn(III)(mu-OH)(mu-piv)2(Me3 tacn)2](ClO4)2 between 4.3 and 9 K. For the latter complex, an energy separation of 24.7-28.0 cm(-1) between the ground and the first excited electronic state was determined. In the S0 state of photosystem II, the T1 relaxation times were measured in the range of 4.3-6.5 K. A comparison with the relaxation data (rate and pre-exponential factor) of the two model complexes and of the S2 state of photosystem II indicates that the Orbach relaxation process is dominant for the S0 state and that its first excited state lies 21.7 +/- 0.4 cm(-1) above its ground state. The results are discussed with respect to the structure of the OEC in photosystem II.
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Affiliation(s)
- L V Kulik
- Max Planck Institute for Bioinorganic Chemistry, 45470 Mülheim/Ruhr, Germany
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17
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Calvo R, Isaacson RA, Abresch EC, Okamura MY, Feher G. Spin-lattice relaxation of coupled metal-radical spin-dimers in proteins: application to Fe(2+)-cofactor (Q(A)(-.), Q(B)(-.), phi(-.)) dimers in reaction centers from photosynthetic bacteria. Biophys J 2002; 83:2440-56. [PMID: 12414679 PMCID: PMC1302331 DOI: 10.1016/s0006-3495(02)75256-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The spin-lattice relaxation times (T(1)) for the reduced quinone acceptors Q(A)(-.) and Q(B)(-.), and the intermediate pheophytin acceptor phi(-.), were measured in native photosynthetic reaction centers (RC) containing a high spin Fe(2+) (S = 2) and in RCs in which Fe(2+) was replaced by diamagnetic Zn(2+). From these data, the contribution of the Fe(2+) to the spin-lattice relaxation of the cofactors was determined. To relate the spin-lattice relaxation rate to the spin-spin interaction between the Fe(2+) and the cofactors, we developed a spin-dimer model that takes into account the zero field splitting and the rhombicity of the Fe(2+) ion. The relaxation mechanism of the spin-dimer involves a two-phonon process that couples the fast relaxing Fe(2+) spin to the cofactor spin. The process is analogous to the one proposed by R. Orbach (Proc. R. Soc. A. (Lond.). 264:458-484) for rare earth ions. The spin-spin interactions are, in general, composed of exchange and dipolar contributions. For the spin dimers studied in this work the exchange interaction, J(o), is predominant. The values of J(o) for Q(A)(-.)Fe(2+), Q(B)(-.)Fe(2+), and phi(-.)Fe(2+) were determined to be (in kelvin) -0.58, -0.92, and -1.3 x 10(-3), respectively. The |J(o)| of the various cofactors (obtained in this work and those of others) could be fitted with the relation exp(-beta(J)d), where d is the distance between cofactor spins and beta(J) had a value of (0.66-0.86) A(-1). The relation between J(o) and the matrix element |V(ij)|(2) involved in electron transfer rates is discussed.
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Affiliation(s)
- Rafael Calvo
- Departamento de Física, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral and INTEC, 3000 Santa Fe, Argentina
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18
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Elsässer C, Brecht M, Bittl R. Pulsed electron-electron double resonance on multinuclear metal clusters: assignment of spin projection factors based on the dipolar interaction. J Am Chem Soc 2002; 124:12606-11. [PMID: 12381206 DOI: 10.1021/ja027348+] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The interaction between two paramagnetic metal centers, a [3Fe-4S](+) cluster and a [NiFe] center, is investigated in the hydrogenase from Desulfovibrio vulgaris Miyazaki F by pulsed ELDOR (electron-electron double resonance). The distance between the metal centers is known from X-ray crystallography. The experimental dipolar spin-spin interaction deviates from the value expected for two point-dipoles located at the centers of the metal clusters. An extended spin-coupling model accounting for the spin coupling in the [3Fe-4S](+) cluster yields the observed interaction under the assumption of a particular magnetic coupling scheme for the three Fe ions. These results demonstrate that pulsed ELDOR can be used to gain insight into the inner structure of a multinuclear metal cluster.
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Affiliation(s)
- Celine Elsässer
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
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19
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Sanakis Y, Macedo AL, Moura I, Moura JJG, Papaefthymiou V, Münck E. Evidence for Antisymmetric Exchange in Cuboidal [3Fe−4S]+ Clusters. J Am Chem Soc 2000. [DOI: 10.1021/ja002658i] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yiannis Sanakis
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
| | - Anjos L. Macedo
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
| | - Isabel Moura
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
| | - Jose J. G. Moura
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
| | - Vasilios Papaefthymiou
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
| | - Eckard Münck
- Contribution from the Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, Institute of Materials Science, NCSR “Demokritos”, 15310 Ag. Paraskevi, Attiki, Greece, Departamento de Química, C.Q.F.B., Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Quinta da Torre, 2825-114 Caparica, Portugal, and Department of Physics, University of Ioannina, Ioannina, Greece
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