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Sushko T, Kavaleuski A, Grabovec I, Kavaleuskaya A, Vakhrameev D, Bukhdruker S, Marin E, Kuzikov A, Masamrekh R, Shumyantseva V, Tsumoto K, Borshchevskiy V, Gilep A, Strushkevich N. A new twist of rubredoxin function in M. tuberculosis. Bioorg Chem 2021; 109:104721. [PMID: 33618255 DOI: 10.1016/j.bioorg.2021.104721] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/19/2021] [Accepted: 02/02/2021] [Indexed: 11/27/2022]
Abstract
Electron transfer mediated by metalloproteins drives many biological processes. Rubredoxins are a ubiquitous [1Fe-0S] class of electron carriers that play an important role in bacterial adaptation to changing environmental conditions. In Mycobacterium tuberculosis, oxidative and acidic stresses as well as iron starvation induce rubredoxins expression. However, their functions during M. tuberculosis infection are unknown. In the present work, we show that rubredoxin B (RubB) is able to efficiently shuttle electrons from cognate reductases, FprA and FdR to support catalytic activity of cytochrome P450s, CYP124, CYP125, and CYP142, which are important for bacterial viability and pathogenicity. We solved the crystal structure of RubB and characterized the interaction between RubB and CYPs using site-directed mutagenesis. Mutations that not only neutralize single charge but also change the specific residues on the surface of RubB did not dramatically decrease activity of studied CYPs. Together with isothermal calorimetry (ITC) experiments, the obtained results suggest that interactions are transient and not highly specific. The redox potential of RubB is -264 mV vs. Ag/AgCl and the measured extinction coefficients are 9931 M-1cm-1 and 8371 M-1cm-1 at 380 nm and 490 nm, respectively. Characteristic parameters of RubB along with the discovered function might be useful for biotechnological applications. Our findings suggest that a switch from ferredoxins to rubredoxins might be crucial for M. tuberculosis to support CYPs activity during the infection.
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Affiliation(s)
- Tatsiana Sushko
- The Institute of Medical Science, the University of Tokyo, Tokyo, Japan
| | - Anton Kavaleuski
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Irina Grabovec
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Anna Kavaleuskaya
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
| | - Daniil Vakhrameev
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow, Institute of Physics and Technology (MIPT), Dolgoprudny, Russia
| | - Sergey Bukhdruker
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow, Institute of Physics and Technology (MIPT), Dolgoprudny, Russia; Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; ESRF - The European Synchrotron, 38000 Grenoble, France
| | - Egor Marin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow, Institute of Physics and Technology (MIPT), Dolgoprudny, Russia
| | - Alexey Kuzikov
- Institute of Biomedical Chemistry, Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - Rami Masamrekh
- Institute of Biomedical Chemistry, Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - Victoria Shumyantseva
- Institute of Biomedical Chemistry, Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - Kouhei Tsumoto
- The Institute of Medical Science, the University of Tokyo, Tokyo, Japan; Department of Bioengineering, School of Engineering, the University of Tokyo, Tokyo, Japan
| | - Valentin Borshchevskiy
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow, Institute of Physics and Technology (MIPT), Dolgoprudny, Russia; Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany; JuStruct: Jülich Center for Structural Biology, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Andrei Gilep
- Institute of Bioorganic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus; Institute of Biomedical Chemistry, Moscow, Russia
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2
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Maiti BK, Almeida RM, Moura I, Moura JJ. Rubredoxins derivatives: Simple sulphur-rich coordination metal sites and its relevance for biology and chemistry. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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3
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Choi O, Sang BI. Extracellular electron transfer from cathode to microbes: application for biofuel production. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:11. [PMID: 27034716 PMCID: PMC4717640 DOI: 10.1186/s13068-016-0426-0] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 01/05/2016] [Indexed: 05/07/2023]
Abstract
Extracellular electron transfer in microorganisms has been applied for bioelectrochemical synthesis utilizing microbes to catalyze anodic and/or cathodic biochemical reactions. Anodic reactions (electron transfer from microbe to anode) are used for current production and cathodic reactions (electron transfer from cathode to microbe) have recently been applied for current consumption for valuable biochemical production. The extensively studied exoelectrogenic bacteria Shewanella and Geobacter showed that both directions for electron transfer would be possible. It was proposed that gram-positive bacteria, in the absence of cytochrome C, would accept electrons using a cascade of membrane-bound complexes such as membrane-bound Fe-S proteins, oxidoreductase, and periplasmic enzymes. Modification of the cathode with the addition of positive charged species such as chitosan or with an increase of the interfacial area using a porous three-dimensional scaffold electrode led to increased current consumption. The extracellular electron transfer from the cathode to the microbe could catalyze various bioelectrochemical reductions. Electrofermentation used electrons from the cathode as reducing power to produce more reduced compounds such as alcohols than acids, shifting the metabolic pathway. Electrofuel could be generated through artificial photosynthesis using electrical energy instead of solar energy in the process of carbon fixation.
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Affiliation(s)
- Okkyoung Choi
- Department of Chemical Engineering, Hanyang University, 222 Wangshimni-ro, Seongdong-gu, Seoul, 04763 South Korea
| | - Byoung-In Sang
- Department of Chemical Engineering, Hanyang University, 222 Wangshimni-ro, Seongdong-gu, Seoul, 04763 South Korea
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4
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Liu J, Chakraborty S, Hosseinzadeh P, Yu Y, Tian S, Petrik I, Bhagi A, Lu Y. Metalloproteins containing cytochrome, iron-sulfur, or copper redox centers. Chem Rev 2014; 114:4366-469. [PMID: 24758379 PMCID: PMC4002152 DOI: 10.1021/cr400479b] [Citation(s) in RCA: 549] [Impact Index Per Article: 54.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Jing Liu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Saumen Chakraborty
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Parisa Hosseinzadeh
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yang Yu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Shiliang Tian
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Igor Petrik
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ambika Bhagi
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Yi Lu
- Department of Chemistry, Department of Biochemistry, and Center for Biophysics
and Computational
Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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5
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Zanello P. The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part I. {Fe(SγCys)4} proteins. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2013.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Draft Genome Sequence of Type Strain Clostridium pasteurianum DSM 525 (ATCC 6013), a Promising Producer of Chemicals and Fuels. GENOME ANNOUNCEMENTS 2013; 1:genomeA00232-12. [PMID: 23469350 PMCID: PMC3587944 DOI: 10.1128/genomea.00232-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 01/07/2013] [Indexed: 11/25/2022]
Abstract
Clostridium pasteurianum, an anaerobic bacterium able to utilize atmospheric free nitrogen for biosynthesis, has recently been proven to be a promising producer of chemicals and fuels, such as 1,3-propanediol and n-butanol. Here, we report the high-quality draft genome sequence of DSM 525, a type strain of C. pasteurianum.
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7
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Ito JI, Tabei Y, Shimizu K, Tomii K, Tsuda K. PDB-scale analysis of known and putative ligand-binding sites with structural sketches. Proteins 2011; 80:747-63. [PMID: 22113700 DOI: 10.1002/prot.23232] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 10/13/2011] [Accepted: 10/18/2011] [Indexed: 11/06/2022]
Abstract
Computational investigation of protein functions is one of the most urgent and demanding tasks in the field of structural bioinformatics. Exhaustive pairwise comparison of known and putative ligand-binding sites, across protein families and folds, is essential in elucidating the biological functions and evolutionary relationships of proteins. Given the vast amounts of data available now, existing 3D structural comparison methods are not adequate due to their computation time complexity. In this article, we propose a new bit string representation of binding sites called structural sketches, which is obtained by random projections of triplet descriptors. It allows us to use ultra-fast all-pair similarity search methods for strings with strictly controlled error rates. Exhaustive comparison of 1.2 million known and putative binding sites finished in ∼30 h on a single core to yield 88 million similar binding site pairs. Careful investigation of 3.5 million pairs verified by TM-align revealed several notable analogous sites across distinct protein families or folds. In particular, we succeeded in finding highly plausible functions of several pockets via strong structural analogies. These results indicate that our method is a promising tool for functional annotation of binding sites derived from structural genomics projects.
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Affiliation(s)
- Jun-Ichi Ito
- Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8568, Japan
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8
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Gamiz-Hernandez AP, Kieseritzky G, Ishikita H, Knapp EW. Rubredoxin Function: Redox Behavior from Electrostatics. J Chem Theory Comput 2011; 7:742-52. [DOI: 10.1021/ct100476h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ana Patricia Gamiz-Hernandez
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195, Berlin, Germany
| | - Gernot Kieseritzky
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195, Berlin, Germany
| | - Hiroshi Ishikita
- Career-Path Promotion Unit for Young Life Scientists, Kyoto University, 202 Building E, Graduate School of Medicine, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - E. W. Knapp
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195, Berlin, Germany
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9
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Luo Y, Ergenekan CE, Fischer JT, Tan ML, Ichiye T. The molecular determinants of the increased reduction potential of the rubredoxin domain of rubrerythrin relative to rubredoxin. Biophys J 2010; 98:560-8. [PMID: 20159152 DOI: 10.1016/j.bpj.2009.11.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 11/03/2009] [Accepted: 11/04/2009] [Indexed: 11/28/2022] Open
Abstract
Based on the crystal structures, three possible sequence determinants have been suggested as the cause of a 285 mV increase in reduction potential of the rubredoxin domain of rubrerythrin over rubredoxin by modulating the polar environment around the redox site. Here, electrostatic calculations of crystal structures of rubredoxin and rubrerythrin and molecular dynamics simulations of rubredoxin wild-type and mutants are used to elucidate the contributions to the increased reduction potential. Asn(160) and His(179) in rubrerythrin versus valines in rubredoxins are predicted to be the major contributors, as the polar side chains contribute significantly to the electrostatic potential in the redox site region. The mutant simulations show both side chains rotating on a nanosecond timescale between two conformations with different electrostatic contributions. Reduction also causes a change in the reduction energy that is consistent with a linear response due to the interesting mechanism of shifting the relative populations of the two conformations. In addition to this, a simulation of a triple mutant indicates the side-chain rotations are approximately anticorrelated so whereas one is in the high potential conformation, the other is in the low potential conformation. However, Ala(176) in rubrerythrin versus a leucine in rubredoxin is not predicted to be a large contributor, because the solvent accessibility increases only slightly in mutant simulations and because it is buried in the interface of the rubrerythrin homodimer.
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Affiliation(s)
- Yan Luo
- Department of Chemistry, Georgetown University, Washington, District of Columbia, USA
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10
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Gámiz-Hernández AP, Galstyan AS, Knapp EW. Understanding Rubredoxin Redox Potentials: Role of H-Bonds on Model Complexes. J Chem Theory Comput 2009; 5:2898-908. [DOI: 10.1021/ct900328c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ana Patricia Gámiz-Hernández
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195 Berlin, Germany
| | - Artur S. Galstyan
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195 Berlin, Germany
| | - Ernst-Walter Knapp
- Institute of Chemistry and Biochemistry, Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Fabeckstrasse 36a, D-14195 Berlin, Germany
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11
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Bönisch H, Schmidt CL, Bianco P, Ladenstein R. Ultrahigh-resolution study on Pyrococcus abyssi rubredoxin: II. Introduction of an O–H···Sγ–Fe hydrogen bond increased the reduction potential by 65 mV. J Biol Inorg Chem 2007; 12:1163-71. [PMID: 17712580 DOI: 10.1007/s00775-007-0289-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 08/01/2007] [Indexed: 10/22/2022]
Abstract
The effect of D-H...S(gamma)-Fe hydrogen bonding on the reduction potential of rubredoxin was investigated by the introduction of an O-H...S(gamma)-Fe hydrogen bond on the surface of Pyrococcus abyssi rubredoxin. The formation of a weak hydrogen bond between Ser44-O(gamma) and Cys42-S(gamma) in mutant W4L/R5S/A44S increased the reduction potential by 56 mV. When side effects of the mutation were taken into account, the contribution of the additional cluster hydrogen bond to the reduction potential was estimated to be +65 mV. The structural analysis was based on ultrahigh-resolution structures of oxidized P. abyssi rubredoxin W4L/R5S and W4L/R5S/A44S refined to 0.69 and 0.86 A, respectively.
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Affiliation(s)
- Heiko Bönisch
- Center of Biosciences, Karolinska Institutet, Hälsovägen 7-9, Huddinge, Sweden.
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12
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Tan ML, Kang C, Ichiye T. The role of backbone stability near Ala44 in the high reduction potential class of rubredoxins. Proteins 2005; 62:708-14. [PMID: 16362979 DOI: 10.1002/prot.20806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Rubredoxins may be separated into high and low reduction potential classes, with reduction potentials differing by approximately 50 mV. Our previous work showed that a local shift in the polar backbone due to an A(44) versus V(44) side-chain size causes this reduction potential difference. However, this work also indicated that in the low potential Clostridium pasteurianum (Cp) rubredoxin, a V(44) --> A(44) mutation causes larger local backbone flexibility, because the V(44) side-chain present in the wild-type (wt) is no longer present to interlock with neighboring residues to stabilize the subsequent G(45). Since Pyrococcus furiosus (Pf) and other high potential rubredoxins generally have a P(45), it was presumed that a G(45) --> P(45) mutation might stabilize a V(44) --> A(44) mutation in Cp rubredoxin. Here crystal structure analysis, energy minimization, and molecular dynamics (MD) were performed for wt V(44)G(45), single mutant A(44)G(45) and double mutant A(44)P(45) Cp, and for wt A(44)P(45) Pf rubredoxins. The local structural, dynamical, and electrostatic properties of Cp gradually approach wt Pf in the order wt Cp to single to double mutant because of greater sequence similarity, as expected. The double mutant A(44)P(45) Cp exhibits increased backbone stability near residue 44 and thus enhances the probability that the backbone dipoles point toward the redox site, which favors an increase in the electrostatic contribution to the reduction potential. It appears that the electrostatic potential of residue 44 and the solvent accessibility to the redox are both determinants for the reduction potentials of homologous rubredoxins. Overall, these results indicate that an A(44) in a rubredoxin may require a P(45) for backbone stability whereas a V(44) can accommodate a G(45), since the valine side-chain can interlock with its neighbors.
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Affiliation(s)
- Ming-Liang Tan
- Department of Chemistry, Georgetown University, Washington, DC 20057, USA
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13
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Park IY, Eidsness MK, Lin IJ, Gebel EB, Youn B, Harley JL, Machonkin TE, Frederick RO, Markley JL, Smith ET, Ichiye T, Kang C. Crystallographic studies of V44 mutants of Clostridium pasteurianum rubredoxin: effects of side-chain size on reduction potential. Proteins 2005; 57:618-25. [PMID: 15382226 DOI: 10.1002/prot.20243] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Understanding the structural origins of differences in reduction potentials is crucial to understanding how various electron transfer proteins modulate their reduction potentials and how they evolve for diverse functional roles. Here, the high-resolution structures of several Clostridium pasteurianum rubredoxin (Cp Rd) variants with changes in the vicinity of the redox site are reported in order to increase this understanding. Our crystal structures of [V44L] (at 1.8 A resolution), [V44A] (1.6 A), [V44G] (2.0 A) and [V44A, G45P] (1.5 A) Rd (all in their oxidized states) show that there is a gradual decrease in the distance between Fe and the amide nitrogen of residue 44 upon reduction in the size of the side chain of residue 44; the decrease occurs from leucine to valine, alanine or glycine and is accompanied by a gradual increase in their reduction potentials. Mutation of Cp Rd at position 44 also changes the hydrogen-bond distance between the amide nitrogen of residue 44 and the sulfur of cysteine 42 in a size-dependent manner. Our results suggest that residue 44 is an important determinant of Rd reduction potential in a manner dictated by side-chain size. Along with the electric dipole moment of the 43-44 peptide bond and the 44-42 NH--S type hydrogen bond, a modulation mechanism for solvent accessibility through residue 41 might regulate the redox reaction of the Rds.
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Affiliation(s)
- Il Yeong Park
- School of Molecular Biosciences, Washington State University, Pullman 99164-4660, USA
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14
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Iyer RB, Silaghi-Dumitrescu R, Kurtz DM, Lanzilotta WN. High-resolution crystal structures of Desulfovibrio vulgaris (Hildenborough) nigerythrin: facile, redox-dependent iron movement, domain interface variability, and peroxidase activity in the rubrerythrins. J Biol Inorg Chem 2005; 10:407-16. [PMID: 15895271 DOI: 10.1007/s00775-005-0650-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2005] [Accepted: 04/13/2005] [Indexed: 10/25/2022]
Abstract
High-resolution crystal structures of Desulfovibrio vulgaris nigerythrin (DvNgr), a member of the rubrerythrin (Rbr) family, demonstrate an approximately 2-A movement of one iron (Fe1) of the diiron site from a carboxylate to a histidine ligand upon conversion of the mixed-valent ([Fe2(II),Fe1(III)]) to diferrous states, even at cryogenic temperatures. This Glu<-->His ligand "toggling" of one iron, which also occurs in DvRbr, thus, appears to be a characteristic feature of Rbr-type diiron sites. Unique features of DvNgr revealed by these structures include redox-induced flipping of a peptide carbonyl that reversibly forms a hydrogen bond to the histidine ligand to Fe1 of the diiron site, an intra-subunit proximal orientation of the rubredoxin-(Rub)-like and diiron domains, and an electron transfer pathway consisting of six covalent and two hydrogen bonds connecting the Rub-like iron with Fe2 of the diiron site. This pathway can account for DvNgr's relatively rapid peroxidase turnover. The characteristic combination of iron sites together with the redox-dependent iron toggling between protein ligands can account for the selectivity of Rbrs for hydrogen peroxide over dioxygen.
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Affiliation(s)
- Ramesh B Iyer
- Department of Chemistry, University of Georgia, Athens, GA 30602, USA
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