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Jobelius H, Bianchino GI, Borel F, Chaignon P, Seemann M. The Reductive Dehydroxylation Catalyzed by IspH, a Source of Inspiration for the Development of Novel Anti-Infectives. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27030708. [PMID: 35163971 PMCID: PMC8837944 DOI: 10.3390/molecules27030708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/11/2022] [Accepted: 01/18/2022] [Indexed: 11/16/2022]
Abstract
The non-mevalonate or also called MEP pathway is an essential route for the biosynthesis of isoprenoid precursors in most bacteria and in microorganisms belonging to the Apicomplexa phylum, such as the parasite responsible for malaria. The absence of this pathway in mammalians makes it an interesting target for the discovery of novel anti-infectives. As last enzyme of this pathway, IspH is an oxygen sensitive [4Fe-4S] metalloenzyme that catalyzes 2H+/2e− reductions and a water elimination by involving non-conventional bioinorganic and bioorganometallic intermediates. After a detailed description of the discovery of the [4Fe-4S] cluster of IspH, this review focuses on the IspH mechanism discussing the results that have been obtained in the last decades using an approach combining chemistry, enzymology, crystallography, spectroscopies, and docking calculations. Considering the interesting druggability of this enzyme, a section about the inhibitors of IspH discovered up to now is reported as well. The presented results constitute a useful and rational help to inaugurate the design and development of new potential chemotherapeutics against pathogenic organisms.
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Affiliation(s)
- Hannah Jobelius
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Gabriella Ines Bianchino
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Franck Borel
- Institut de Biologie Structurale, Université Grenoble Alpes/CEA/CNRS, 38000 Grenoble, France;
| | - Philippe Chaignon
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
| | - Myriam Seemann
- Equipe Chimie Biologique et Applications Thérapeutiques, Institut de Chimie de Strasbourg UMR 7177, Université de Strasbourg/CNRS, 4, rue Blaise Pascal, 67070 Strasbourg, France; (H.J.); (G.I.B.); (P.C.)
- Correspondence:
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Steenbock T, Herrmann C. Toward an automated analysis of exchange pathways in spin-coupled systems. J Comput Chem 2018; 39:81-92. [PMID: 29044625 DOI: 10.1002/jcc.25081] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Accepted: 09/24/2017] [Indexed: 01/25/2023]
Abstract
Understanding (super-)exchange coupling between local spins is an important task in theoretical chemistry and solid-state physics. We show that a Green's-function approach introduced earlier (Liechtenstein et al., J. Phys. F 1984, 14, L125; Steenbock et al., J. Chem. Theory Comput. 2015, 11, 5651) can be used for analyzing exchange coupling pathways in an automated fashion rather than by visual inspection of molecular orbitals. We demonstrate the capabilities of this approach by comparing it to previously published pathway analyses for hydroxy-bridged dinuclear copper complexes and an oxo-bridged dinuclear manganese complex, and employ it for discriminating between through-space and through-bond pathways in a naphthalene-bridged bisnickelocene complex. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Torben Steenbock
- Institute of Inorganic and Applied Chemistry, Chemistry Department, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg, 20146, Germany
| | - Carmen Herrmann
- Institute of Inorganic and Applied Chemistry, Chemistry Department, University of Hamburg, Martin-Luther-King-Platz 6, Hamburg, 20146, Germany
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Dong M, Horitani M, Dzikovski B, Pandelia ME, Krebs C, Freed JH, Hoffman BM, Lin H. Organometallic Complex Formed by an Unconventional Radical S-Adenosylmethionine Enzyme. J Am Chem Soc 2016; 138:9755-8. [PMID: 27465315 DOI: 10.1021/jacs.6b04155] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pyrococcus horikoshii Dph2 (PhDph2) is an unusual radical S-adenosylmethionine (SAM) enzyme involved in the first step of diphthamide biosynthesis. It catalyzes the reaction by cleaving SAM to generate a 3-amino-3-carboxypropyl (ACP) radical. To probe the reaction mechanism, we synthesized a SAM analogue (SAMCA), in which the ACP group of SAM is replaced with a 3-carboxyallyl group. SAMCA is cleaved by PhDph2, yielding a paramagnetic (S = 1/2) species, which is assigned to a complex formed between the reaction product, α-sulfinyl-3-butenoic acid, and the [4Fe-4S] cluster. Electron-nuclear double resonance (ENDOR) measurements with (13)C and (2)H isotopically labeled SAMCA support a π-complex between the C═C double bond of α-sulfinyl-3-butenoic acid and the unique iron of the [4Fe-4S] cluster. This is the first example of a radical SAM-related [4Fe-4S](+) cluster forming an organometallic complex with an alkene, shedding additional light on the mechanism of PhDph2 and expanding our current notions for the reactivity of [4Fe-4S] clusters in radical SAM enzymes.
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Affiliation(s)
- Min Dong
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Masaki Horitani
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States
| | - Boris Dzikovski
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Maria-Eirini Pandelia
- Department of Biochemistry, Brandeis University , Waltham, Massachusetts 02453, United States
| | - Carsten Krebs
- Department of Chemistry and Department of Biochemistry and Molecular Biology, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Jack H Freed
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Brian M Hoffman
- Department of Chemistry, Northwestern University , Evanston, Illinois 60208, 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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Cutsail GE, Telser J, Hoffman BM. Advanced paramagnetic resonance spectroscopies of iron-sulfur proteins: Electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM). BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1370-94. [PMID: 25686535 DOI: 10.1016/j.bbamcr.2015.01.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 01/29/2015] [Accepted: 01/29/2015] [Indexed: 12/20/2022]
Abstract
The advanced electron paramagnetic resonance (EPR) techniques, electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM) spectroscopies, provide unique insights into the structure, coordination chemistry, and biochemical mechanism of nature's widely distributed iron-sulfur cluster (FeS) proteins. This review describes the ENDOR and ESEEM techniques and then provides a series of case studies on their application to a wide variety of FeS proteins including ferredoxins, nitrogenase, and radical SAM enzymes. This article is part of a Special Issue entitled: Fe/S proteins: Analysis, structure, function, biogenesis and diseases.
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Affiliation(s)
- George E Cutsail
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Joshua Telser
- Department of Biological, Chemical and Physical Sciences, Roosevelt University, Chicago, IL 60605, USA
| | - Brian M Hoffman
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA.
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Wang W, Oldfield E. Biometallorganische Chemie mit IspG und IspH: Struktur, Funktion und Hemmung der an der Isoprenoid-Biosynthese beteiligten [Fe 4S 4]-Proteine. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201306712] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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6
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Wang W, Oldfield E. Bioorganometallic chemistry with IspG and IspH: structure, function, and inhibition of the [Fe(4)S(4)] proteins involved in isoprenoid biosynthesis. Angew Chem Int Ed Engl 2014; 53:4294-310. [PMID: 24481599 DOI: 10.1002/anie.201306712] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Indexed: 11/12/2022]
Abstract
Enzymes of the methylerythritol phosphate pathway of isoprenoid biosynthesis are attractive anti-infective drug targets. The last two enzymes of this pathway, IspG and IspH, are [Fe4 S4 ] proteins that are not produced by humans and catalyze 2 H(+) / 2 e(-) reductions with novel mechanisms. In this Review, we summarize recent advances in structural, mechanistic, and inhibitory studies of these two enzymes. In particular, mechanistic proposals involving bioorganometallic intermediates are presented, and compared with other mechanistic possibilities. In addition, inhibitors based on substrate analogues as well as developed by rational design and compound-library screening, are discussed. The results presented support bioorganometallic catalytic mechanisms for IspG and IspH, and open up new routes to anti-infective drug design targeting [Fe4 S4 ] clusters in proteins.
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Affiliation(s)
- Weixue Wang
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (USA)
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Wang W, Wang K, Span I, Jauch J, Bacher A, Groll M, Oldfield E. Are free radicals involved in IspH catalysis? An EPR and crystallographic investigation. J Am Chem Soc 2012; 134:11225-34. [PMID: 22687151 DOI: 10.1021/ja303445z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The [4Fe-4S] protein IspH in the methylerythritol phosphate isoprenoid biosynthesis pathway is an important anti-infective drug target, but its mechanism of action is still the subject of debate. Here, by using electron paramagnetic resonance (EPR) spectroscopy and (2)H, (17)O, and (57)Fe isotopic labeling, we have characterized and assigned two key reaction intermediates in IspH catalysis. The results are consistent with the bioorganometallic mechanism proposed earlier, and the mechanism is proposed to have similarities to that of ferredoxin, thioredoxin reductase, in that one electron is transferred to the [4Fe-4S](2+) cluster, which then performs a formal two-electron reduction of its substrate, generating an oxidized high potential iron-sulfur protein (HiPIP)-like intermediate. The two paramagnetic reaction intermediates observed correspond to the two intermediates proposed in the bioorganometallic mechanism: the early π-complex in which the substrate's 3-CH(2)OH group has rotated away from the reduced iron-sulfur cluster, and the next, η(3)-allyl complex formed after dehydroxylation. No free radical intermediates are observed, and the two paramagnetic intermediates observed do not fit in a Birch reduction-like or ferraoxetane mechanism. Additionally, we show by using EPR spectroscopy and X-ray crystallography that two substrate analogues (4 and 5) follow the same reaction mechanism.
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Affiliation(s)
- Weixue Wang
- Center for Biophysics and Computational Biology, 607 South Mathews Avenue, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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9
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Anisotropic mixing of spin levels in spin-admixed tetrameric iron–sulfur clusters with spin frustration. Chem Phys 2002. [DOI: 10.1016/s0301-0104(02)00310-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Belinsky MI. The spin-coupling model of zero-field splitting for trimeric [3Fe–4S] and mixed-metal [3FeZn–4S] clusters of ferredoxins from Pyrococcus furiosus. Chem Phys 2001. [DOI: 10.1016/s0301-0104(00)00361-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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Belinsky MI. Exchange variation of zero-field splittings in [Fe4S4]+ clusters of ferredoxins with high-spin S=3/2 ground state. Chem Phys 2000. [DOI: 10.1016/s0301-0104(00)00047-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Matusiewicz M, Czerwiński M, Kasperczyk J, Kityk IV. Description of spin interactions in model [Fe6S6]4+ supercluster. J Chem Phys 1999. [DOI: 10.1063/1.480024] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Biquadratic exchange results in strong splittings and shifts of spin levels of [Fe4S4]+ clusters in Heisenberg and double exchange models. Chem Phys 1997. [DOI: 10.1016/s0301-0104(97)00202-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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14
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Le Pape L, Lamotte B, Mouesca JM, Rius G. Paramagnetic States of Four Iron−Four Sulfur Clusters. 1. EPR Single-Crystal Study of 3+ and 1+ Clusters of an Asymmetrical Model Compound and General Model for the Interpretation of the g-Tensors of These Two Redox States. J Am Chem Soc 1997. [DOI: 10.1021/ja963349o] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Laurent Le Pape
- Contribution from the Département de Recherche Fondamentale sur la Matière Condensée, SCIB/SCPM, C.E.A./Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Bernard Lamotte
- Contribution from the Département de Recherche Fondamentale sur la Matière Condensée, SCIB/SCPM, C.E.A./Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Jean-Marie Mouesca
- Contribution from the Département de Recherche Fondamentale sur la Matière Condensée, SCIB/SCPM, C.E.A./Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Gérard Rius
- Contribution from the Département de Recherche Fondamentale sur la Matière Condensée, SCIB/SCPM, C.E.A./Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
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17
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Beinert H, Kennedy MC, Stout CD. Aconitase as Ironminus signSulfur Protein, Enzyme, and Iron-Regulatory Protein. Chem Rev 1996; 96:2335-2374. [PMID: 11848830 DOI: 10.1021/cr950040z] [Citation(s) in RCA: 422] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Helmut Beinert
- Institute for Enzyme Research, Graduate School, and Department of Biochemistry, College of Agricultural and Life Sciences, University of Wisconsin, Madison, Wisconsin 53705, Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, and Department of Molecular Biology, The Scripps Research Institute, La Jolla, California 92037
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18
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Belinsky MI. Induced paramagnetism and hyperfine interactions in the {[Fe4S4]-Fe} active site of Escherichia coli sulfite reductase. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(95)01456-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Heering HA, Bulsink YB, Hagen WR, Meyer TE. Reversible super-reduction of the cubane [4Fe-4S](3+;2+;1+) in the high-potential iron-sulfur protein under non-denaturing conditions. EPR spectroscopic and electrochemical studies. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 232:811-817. [PMID: 7588720 DOI: 10.1111/j.1432-1033.1995.0811a.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The reversible 2 x 1 e- reduction of the cubane cluster from oxidized to reduced to super-reduced states ([4Fe-4S]3+<-->[4Fe-4S]2+<-->[4Fe-4S]1+) was studied in high-potential iron-sulfur proteins (HiPIPs). Super-reduction to the 1+ state was not observed in any of the seven HiPIPs tested during cyclic voltammetry (down to -0.95 V). However, equilibration at low potential (pH 7.5) of Rhodopila globiformis HiPIP yields a transient peak around -0.47 V due to the oxidation of super-reduced HiPIP adsorbed at the electrode. The peak area depends on the equilibration potential according to a one-electron Nernst curve with a half-wave potential at -0.91 V. Reduction of R. globiformis HiPIP with titanium (III)citrate at pH 9.5 is very slow [pseudo-first-order half-life of 23 min with a 100-fold excess Ti(III)] but is reversible, and the EPR spectrum with g values of 2.04 and 1.92 is similar to that of reduced [4Fe-4S]1+ ferredoxins. Chemical or electrochemical reoxidation of the super-reduced form resulted in an EPR spectrum with g parallel = 2.12 and g perpendicular = 2.03, i.e. identical to that of oxidized HiPIP. From the equilibrium concentration of super-reduced HiPIP at a low concentration of Ti(III), a reduction potential of -0.64 V can be estimated. Super-reduction of the large HiPIP (iso-2) from Rhodospirillum salinarum is also possible with Ti(III)(gz = 2.05) but the super-reduced state is unstable. No super-reduction with Ti(III) was observed for the other HiPIPs. The difference between the electrochemically observed reduction potential and oxidation potential is explained by a fast and reversible conformational change upon super-reduction. The rate of super-reduction with Ti(III) is limited by the small amount (0.1%) of HiPIP in the 2+ state with the super-reduced conformation.
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Affiliation(s)
- H A Heering
- Department of Biochemistry, Wageningen Agricultural University, The Netherlands
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Heering HA, Bulsink YBM, Hagen WR, Meyer TE. Reversible Super-Reduction of the Cubane [4Fe-4S](3+;2+;1+) in the High-Potential Iron-Sulfur Protein Under Non-Denaturing Conditions. EPR Spectroscopic and Electrochemical Studies. ACTA ACUST UNITED AC 1995. [DOI: 10.1111/j.1432-1033.1995.tb20877.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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The electronic structure of FeS centers in proteins and models a contribution to the understanding of their electron transfer properties. STRUCTURE AND BONDING 1995. [DOI: 10.1007/3-540-59105-2_1] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Murray KS. The Magnetochemistry of Homo-and Hetero-Tetranuclear First-Row d-Block Complexes. ADVANCES IN INORGANIC CHEMISTRY 1995. [DOI: 10.1016/s0898-8838(08)60119-1] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Belinskii M. Exchange variation of hyperfine characteristics of tetrameric [Mn3(III)Mn(IV)] and [Mn3(IV)Mn(III)] clusters. Chem Phys 1994. [DOI: 10.1016/0301-0104(94)00275-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Bertini I, Felli IC, Kastrau DH, Luchinat C, Piccioli M, Viezzoli MS. Sequence-specific assignment of the 1H and 15N nuclear magnetic resonance spectra of the reduced recombinant high-potential iron-sulfur protein I from Ectothiorhodospira halophila. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 225:703-14. [PMID: 7957186 DOI: 10.1111/j.1432-1033.1994.00703.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A 1H and 15N NMR investigation through two-dimensional and three-dimensional spectroscopy has been performed on the reduced form ([Fe4S4]2+) of the recombinant high-potential iron-sulfur protein (HiPIP) I from Ectothiorhodospira halophila expressed in Escherichia coli. [Fe4S4]2+ clusters in proteins are paramagnetic with a relatively low mu eff of about 0.8 mu B/iron ion, but the paramagnetic effects on nuclear relaxation are so strong as to yield T1 values of a few milliseconds and linewidths of hundreds of hertz for the nuclei closet to the paramagnetic center. Despite these features, 71 out of 73 residues were identified, most of which were assigned completely as far as proton resonances are concerned; as many as 68 residues could be assigned without any reference to the existing X-ray structure. A total of 88% of all protein protons and 58 out of 69 peptide HN nitrogen signals were assigned. To the best of our knowledge, this is the most extensive 1H assignment of a paramagnetic protein to date. Protons sensitive to the proximity of the cluster were assigned through suitable NOE spectroscopy experiments. Three out of the four coordinated cysteines were assigned, and two residues have been identified whose peptide HN protons give rise to H bonds with coordinated sulfur atoms. The inter-residue NOE cross peaks are in qualitative agreement with the secondary and tertiary structure as obtained from the available X-ray crystallographic analysis of the wild-type protein at 250-pm resolution. It is therefore shown that the expressed protein is properly folded and that it is a reliable model for the wild-type protein. These data are meaningful for the detection of structural differences among mutants in future studies.
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Affiliation(s)
- I Bertini
- Department of Chemistry, University of Florence, Italy
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Belinskii M. Heisenberg model for tetrameric iron clusters in high-potential iron-sulfur proteins. I. Exchange states, g-factors, hyperfine interactions. Chem Phys 1993. [DOI: 10.1016/0301-0104(93)85004-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Belinskii M. Spin coupling model for tetrameric iron clusters in ferredoxins. III. Double exchange in distorted cluster. Chem Phys 1993. [DOI: 10.1016/0301-0104(93)80214-t] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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30
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Belinskii M. Spin coupling model for tetrameric iron clusters in ferredoxins. II. Hyperfine interactions, magnetism, high-spin systems. Chem Phys 1993. [DOI: 10.1016/0301-0104(93)80117-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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