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An S, Zhang Y, Wang T, Luo M, Li C. Molecular characterization of glutaredoxin 2 from Ostrinia furnacalis. Integr Zool 2012; 8 Suppl 1:30-8. [PMID: 23621469 DOI: 10.1111/j.1749-4877.2012.00301.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glutaredoxins (GRXs) play very important roles in maintaining intracellular redox homeostasis. In the present study, the full-length cDNA sequence encoding GRX2, named OfurGRX2 (GenBank accession no. GU393246), was obtained from Ostrinia furnacalis, using reverse transcription polymerase chain reaction and rapid amplification of cDNA ends. Sequence analysis revealed that the open reading frame of OfurGRX2 consists of 351 nucleotides encoding 116 amino acid residues with a predicted molecular weight of 12.6 kDa. Homolog research revealed that OfurGRX2 shares a common active site, CPYC/CPFC, with other insect counterparts. Expression profiles revealed that OfurGRX2 is a ubiquitous gene expressed in insect heads, fat bodies, epidermises, mid guts and muscles. The OfurGRX2 transcript peaked in 36-h larvae of 4th instars, and then suddenly declined in the molting stage. Hormone treatment experiments revealed that 20-hydroxyecodyson (20e) significantly induces the expression of the OfurGRX2 transcript, whereas juvenile hormone (JH) counteracts 20e effects. Adverse stress factors (including starvation, ultraviolet light, mechanical injury, Escherichia coli exposure, and high and low temperatures) dramatically induced OfurGRXGRX2 transcript expression, which confirmed for the first time that GRX2 play important roles in insecta during exposure to adverse environments.
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Affiliation(s)
- Shiheng An
- College of Plant Protection, Henan Agricultural University, Zhengzhou, China
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Meyer Y, Belin C, Delorme-Hinoux V, Reichheld JP, Riondet C. Thioredoxin and glutaredoxin systems in plants: molecular mechanisms, crosstalks, and functional significance. Antioxid Redox Signal 2012; 17:1124-60. [PMID: 22531002 DOI: 10.1089/ars.2011.4327] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Thioredoxins (Trx) and glutaredoxins (Grx) constitute families of thiol oxidoreductases. Our knowledge of Trx and Grx in plants has dramatically increased during the last decade. The release of the Arabidopsis genome sequence revealed an unexpectedly high number of Trx and Grx genes. The availability of several genomes of vascular and nonvascular plants allowed the establishment of a clear classification of the genes and the chronology of their appearance during plant evolution. Proteomic approaches have been developed that identified the putative Trx and Grx target proteins which are implicated in all aspects of plant growth, including basal metabolism, iron/sulfur cluster formation, development, adaptation to the environment, and stress responses. Analyses of the biochemical characteristics of specific Trx and Grx point to a strong specificity toward some target enzymes, particularly within plastidial Trx and Grx. In apparent contradiction with this specificity, genetic approaches show an absence of phenotype for most available Trx and Grx mutants, suggesting that redundancies also exist between Trx and Grx members. Despite this, the isolation of mutants inactivated in multiple genes and several genetic screens allowed the demonstration of the involvement of Trx and Grx in pathogen response, phytohormone pathways, and at several control points of plant development. Cytosolic Trxs are reduced by NADPH-thioredoxin reductase (NTR), while the reduction of Grx depends on reduced glutathione (GSH). Interestingly, recent development integrating biochemical analysis, proteomic data, and genetics have revealed an extensive crosstalk between the cytosolic NTR/Trx and GSH/Grx systems. This crosstalk, which occurs at multiple levels, reveals the high plasticity of the redox systems in plants.
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Affiliation(s)
- Yves Meyer
- Laboratoire Génome et Développement des Plantes, Université de Perpignan, Perpignan, France
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53
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Streptococcus pneumoniae uses glutathione to defend against oxidative stress and metal ion toxicity. J Bacteriol 2012; 194:6248-54. [PMID: 22984260 DOI: 10.1128/jb.01393-12] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The thiol-containing tripeptide glutathione is an important cellular constituent of many eukaryotic and prokaryotic cells. In addition to its disulfide reductase activity, glutathione is known to protect cells from many forms of physiological stress. This report represents the first investigation into the role of glutathione in the Gram-positive pathogen Streptococcus pneumoniae. We demonstrate that pneumococci import extracellular glutathione using the ABC transporter substrate binding protein GshT. Mutation of gshT and the gene encoding glutathione reductase (gor) increases pneumococcal sensitivity to the superoxide generating compound paraquat, illustrating the importance of glutathione utilization in pneumococcal oxidative stress resistance. In addition, the gshT and gor mutant strains are hypersensitive to challenge with the divalent metal ions copper, cadmium, and zinc. The importance of glutathione utilization in pneumococcal colonization and invasion of the host is demonstrated by the attenuated phenotype of the gshT mutant strain in a mouse model of infection.
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Benyamina SM, Baldacci-Cresp F, Couturier J, Chibani K, Hopkins J, Bekki A, de Lajudie P, Rouhier N, Jacquot JP, Alloing G, Puppo A, Frendo P. TwoSinorhizobium melilotiglutaredoxins regulate iron metabolism and symbiotic bacteroid differentiation. Environ Microbiol 2012; 15:795-810. [DOI: 10.1111/j.1462-2920.2012.02835.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Li H, Outten CE. Monothiol CGFS glutaredoxins and BolA-like proteins: [2Fe-2S] binding partners in iron homeostasis. Biochemistry 2012; 51:4377-89. [PMID: 22583368 DOI: 10.1021/bi300393z] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monothiol glutaredoxins (Grxs) with a signature CGFS active site and BolA-like proteins have recently emerged as novel players in iron homeostasis. Elegant genetic and biochemical studies examining the functional and physical interactions of CGFS Grxs in the fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe have unveiled their essential roles in intracellular iron signaling, iron trafficking, and the maturation of Fe-S cluster proteins. Biophysical and biochemical analyses of the [2Fe-2S] bridging interaction between CGFS Grxs and a BolA-like protein in S. cerevisiae provided the first molecular-level understanding of the iron regulation mechanism in this model eukaryote and established the ubiquitous CGFS Grxs and BolA-like proteins as novel Fe-S cluster-binding regulatory partners. Parallel studies focused on Escherichia coli and human homologues for CGFS Grxs and BolA-like proteins have supported the studies in yeast and provided additional clues about their involvement in cellular iron metabolism. Herein, we review recent progress in uncovering the cellular and molecular mechanisms by which CGFS Grxs and BolA-like proteins help regulate iron metabolism in both eukaryotic and prokaryotic organisms.
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Affiliation(s)
- Haoran Li
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, United States
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Enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from S-sulfocysteine increases L-cysteine production in Escherichia coli. Microb Cell Fact 2012; 11:62. [PMID: 22607201 PMCID: PMC3528435 DOI: 10.1186/1475-2859-11-62] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 05/05/2012] [Indexed: 11/17/2022] Open
Abstract
Background Escherichia coli has two L-cysteine biosynthetic pathways; one is synthesized from O-acetyl L-serine (OAS) and sulfate by L-cysteine synthase (CysK), and another is produced via S-sulfocysteine (SSC) from OAS and thiosulfate by SSC synthase (CysM). SSC is converted into L-cysteine and sulfite by an uncharacterized reaction. As thioredoxins (Trx1 and Trx2) and glutaredoxins (Grx1, Grx2, Grx3, Grx4, and NrdH) are known as reductases of peptidyl disulfides, overexpression of such reductases might be a good way for improving L-cysteine production to accelerate the reduction of SSC in E. coli. Results Because the redox enzymes can reduce the disulfide that forms on proteins, we first tested whether these enzymes catalyze the reduction of SSC to L-cysteine. All His-tagged recombinant enzymes, except for Grx4, efficiently convert SSC into L-cysteine in vitro. Overexpression of Grx1 and NrdH enhanced a 15-40% increase in the E. coliL-cysteine production. On the other hand, disruption of the cysM gene cancelled the effect caused by the overexpression of Grx1 and NrdH, suggesting that its improvement was due to the efficient reduction of SSC under the fermentative conditions. Moreover, L-cysteine production in knockout mutants of the sulfite reductase genes (ΔcysI and ΔcysJ) and the L-cysteine synthase gene (ΔcysK) each decreased to about 50% of that in the wild-type strain. Interestingly, there was no significant difference in L-cysteine production between wild-type strain and gene deletion mutant of the upstream pathway of sulfite (ΔcysC or ΔcysH). These results indicate that sulfite generated from the SSC reduction is available as the sulfur source to produce additional L-cysteine molecule. It was finally found that in the E. coliL-cysteine producer that co-overexpress glutaredoxin (NrdH), sulfite reductase (CysI), and L-cysteine synthase (CysK), there was the highest amount of L-cysteine produced per cell. Conclusions In this work, we showed that Grx1 and NrdH reduce SSC to L-cysteine, and the generated sulfite is then utilized as the sulfur source to produce additional L-cysteine molecule through the sulfate pathway in E. coli. We also found that co-overexpression of NrdH, CysI, and CysK increases L-cysteine production. Our results propose that the enhancement of thioredoxin/glutaredoxin-mediated L-cysteine synthesis from SSC is a novel method for improvement of L-cysteine production.
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Zaffagnini M, Bedhomme M, Marchand CH, Morisse S, Trost P, Lemaire SD. Redox regulation in photosynthetic organisms: focus on glutathionylation. Antioxid Redox Signal 2012; 16:567-86. [PMID: 22053845 DOI: 10.1089/ars.2011.4255] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
SIGNIFICANCE In photosynthetic organisms, besides the well-established disulfide/dithiol exchange reactions specifically controlled by thioredoxins (TRXs), protein S-glutathionylation is emerging as an alternative redox modification occurring under stress conditions. This modification, consisting of the formation of a mixed disulfide between glutathione and a protein cysteine residue, can not only protect specific cysteines from irreversible oxidation but also modulate protein activities and appears to be specifically controlled by small disulfide oxidoreductases of the TRX superfamily named glutaredoxins (GRXs). RECENT STUDIES In recent times, several studies allowed significant progress in this area, mostly due to the identification of several plant proteins undergoing S-glutathionylation and to the characterization of the molecular mechanisms and the proteins involved in the control of this modification. CRITICAL ISSUES This article provides a global overview of protein glutathionylation in photosynthetic organisms with particular emphasis on the mechanisms of protein glutathionylation and deglutathionylation and a focus on the role of GRXs. Then, we describe the methods employed for identification of glutathionylated proteins in photosynthetic organisms and review the targets and the possible physiological functions of protein glutathionylation. FUTURE DIRECTIONS In order to establish the importance of protein S-glutathionylation in photosynthetic organisms, future studies should be aimed at delineating more accurately the molecular mechanisms of glutathionylation and deglutathionylation reactions, at identifying proteins undergoing S-glutathionylation in vivo under diverse conditions, and at investigating the importance of redoxins, GRX, and TRX, in the control of this redox modification in vivo.
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Affiliation(s)
- Mirko Zaffagnini
- Laboratoire de Biologie Moléculaire et Cellulaire des Eucaryotes, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Institut de Biologie Physico-Chimique, Paris, France
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Yeung N, Gold B, Liu NL, Prathapam R, Sterling HJ, Willams ER, Butland G. The E. coli monothiol glutaredoxin GrxD forms homodimeric and heterodimeric FeS cluster containing complexes. Biochemistry 2011; 50:8957-69. [PMID: 21899261 DOI: 10.1021/bi2008883] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Monothiol glutaredoxins (mono-Grx) represent a highly evolutionarily conserved class of proteins present in organisms ranging from prokaryotes to humans. Mono-Grxs have been implicated in iron sulfur (FeS) cluster biosynthesis as potential scaffold proteins and in iron homeostasis via an FeS-containing complex with Fra2p (homologue of E. coli BolA) in yeast and are linked to signal transduction in mammalian systems. However, the function of the mono-Grx in prokaryotes and the nature of an interaction with BolA-like proteins have not been established. Recent genome-wide screens for E. coli genetic interactions reported the synthetic lethality (combination of mutations leading to cell death; mutation of only one of these genes does not) of a grxD mutation when combined with strains defective in FeS cluster biosynthesis (isc operon) functions [Butland, G., et al. (2008) Nature Methods 5, 789-795]. These data connected the only E. coli mono-Grx, GrxD to a potential role in FeS cluster biosynthesis. We investigated GrxD to uncover the molecular basis of this synthetic lethality and observed that GrxD can form FeS-bound homodimeric and BolA containing heterodimeric complexes. These complexes display substantially different spectroscopic and functional properties, including the ability to act as scaffold proteins for intact FeS cluster transfer to the model [2Fe-2S] acceptor protein E. coli apo-ferredoxin (Fdx), with the homodimer being significantly more efficient. In this work, we functionally dissect the potential cellular roles of GrxD as a component of both homodimeric and heterodimeric complexes to ultimately uncover if either of these complexes performs functions linked to FeS cluster biosynthesis.
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Affiliation(s)
- N Yeung
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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59
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Reeves SA, Parsonage D, Nelson KJ, Poole LB. Kinetic and thermodynamic features reveal that Escherichia coli BCP is an unusually versatile peroxiredoxin. Biochemistry 2011; 50:8970-81. [PMID: 21910476 DOI: 10.1021/bi200935d] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In Escherichia coli, bacterioferritin comigratory protein (BCP) is a peroxiredoxin (Prx) that catalyzes the reduction of H(2)O(2) and organic hydroperoxides. This protein, along with plant PrxQ, is a founding member of one of the least studied subfamilies of Prxs. Recent structural data have suggested that proteins in the BCP/PrxQ group can exist as monomers or dimers; we report here that, by analytical ultracentrifugation, both oxidized and reduced E. coli BCP behave as monomers in solution at concentrations as high as 200 μM. Unexpectedly, thioredoxin (Trx1)-dependent peroxidase assays conducted by stopped-flow spectroscopy demonstrated that V(max,app) increases with increasing Trx1 concentrations, indicating a nonsaturable interaction (K(m) > 100 μM). At a physiologically reasonable Trx1 concentration of 10 μM, the apparent K(m) value for H(2)O(2) is ~80 μM, and overall, the V(max)/K(m) for H(2)O(2), which remains constant at the various Trx1 concentrations (consistent with a ping-pong mechanism), is ~1.3 × 10(4) M(-1) s(-1). Our kinetic analyses demonstrated that BCP can utilize a variety of reducing substrates, including Trx1, Trx2, Grx1, and Grx3. BCP exhibited a high redox potential of -145.9 ± 3.2 mV, the highest to date observed for a Prx. Moreover, BCP exhibited a broad peroxide specificity, with comparable rates for H(2)O(2) and cumene hydroperoxide. We determined a pK(a) of ~5.8 for the peroxidatic cysteine (Cys45) using both spectroscopic and activity titration data. These findings support an important role for BCP in interacting with multiple substrates and remaining active under highly oxidizing cellular conditions, potentially serving as a defense enzyme of last resort.
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Affiliation(s)
- Stacy A Reeves
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157, USA
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Abstract
Dr. Arne Holmgren (Ph.D., 1968) is recognized here as a redox pioneer, because he has published at least one article on redox biology that has been cited over 1000 times and has published at least 10 articles, each cited over 100 times. He is widely known for his seminal discoveries and in-depth studies of thioredoxins, thioredoxin reductases, and glutaredoxins. Dr. Holmgren, active throughout his career at Karolinska Institutet, Sweden, has led the field of research about these classes of proteins for more than 45 years, continuously building upon his sequence determination of Escherichia coli thioredoxin in the late 1960s and discovery of the thioredoxin fold in the 1970s. He discovered and named glutaredoxin and he determined the structure and function of several members of these glutathione-dependent disulfide oxidoreductases. He still continues to broaden the frontiers of knowledge of thioredoxin and glutaredoxin systems. The thioredoxin fold is today recognized as one of the most common protein folds and the intriguing complexity of redox systems, redox signaling, and redox control of cellular function is constantly increasing. The legacy of Dr. Holmgren's research is therefore highly relevant and important also in the context of present science. In a tribute to his work, questions need to be addressed toward the physiological importance of redox signaling and the impact of glutaredoxin and thioredoxin systems on health and disease. Dr. Holmgren helped lay the foundation for the redox biology field and opened new vistas in the process. He is truly a redox pioneer.
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Affiliation(s)
- Elias S J Arnér
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
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Couturier J, Ströher E, Albetel AN, Roret T, Muthuramalingam M, Tarrago L, Seidel T, Tsan P, Jacquot JP, Johnson MK, Dietz KJ, Didierjean C, Rouhier N. Arabidopsis chloroplastic glutaredoxin C5 as a model to explore molecular determinants for iron-sulfur cluster binding into glutaredoxins. J Biol Chem 2011; 286:27515-27. [PMID: 21632542 DOI: 10.1074/jbc.m111.228726] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Unlike thioredoxins, glutaredoxins are involved in iron-sulfur cluster assembly and in reduction of specific disulfides (i.e. protein-glutathione adducts), and thus they are also important redox regulators of chloroplast metabolism. Using GFP fusion, AtGrxC5 isoform, present exclusively in Brassicaceae, was shown to be localized in chloroplasts. A comparison of the biochemical, structural, and spectroscopic properties of Arabidopsis GrxC5 (WCSYC active site) with poplar GrxS12 (WCSYS active site), a chloroplastic paralog, indicated that, contrary to the solely apomonomeric GrxS12 isoform, AtGrxC5 exists as two forms when expressed in Escherichia coli. The monomeric apoprotein possesses deglutathionylation activity mediating the recycling of plastidial methionine sulfoxide reductase B1 and peroxiredoxin IIE, whereas the dimeric holoprotein incorporates a [2Fe-2S] cluster. Site-directed mutagenesis experiments and resolution of the x-ray crystal structure of AtGrxC5 in its holoform revealed that, although not involved in its ligation, the presence of the second active site cysteine (Cys(32)) is required for cluster formation. In addition, thiol titrations, fluorescence measurements, and mass spectrometry analyses showed that, despite the presence of a dithiol active site, AtGrxC5 does not form any inter- or intramolecular disulfide bond and that its activity exclusively relies on a monothiol mechanism.
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Affiliation(s)
- Jérémy Couturier
- Unité Mixte de Recherches 1136, Institut National de la Recherche Agronomique-Nancy Université, Interactions Arbres Microorganismes, Institut Fédératif de Recherche 110 Ecosystèmes Forestiers, Agroressources, Biomolécule et Alimentation, 54506 Vandoeuvre-lès-Nancy Cedex, France
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Ken CF, Chen IJ, Lin CT, Liu SM, Wen L, Lin CT. Monothiol glutaredoxin cDNA from Taiwanofungus camphorata: a novel CGFS-type glutaredoxin possessing glutathione reductase activity. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:3828-3835. [PMID: 21395221 DOI: 10.1021/jf1048113] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Glutaredoxins (Grxs) play important roles in the redox system via reduced glutathione as a reductant. A TcmonoGrx cDNA (1039 bp, EU158772) encoding a putative monothiol Grx was cloned from Taiwanofungus camphorata (formerly named Antrodia camphorata). The deduced amino acid sequence is conserved among the reported monothiol Grxs. Two 3-D homology structures of the TcmonoGrx based on known structures of human Grx3 (pdb: 2DIY_A) and Mus musculus Grx3 (pdb: 1WIK_A) have been created. To characterize the TcmonoGrx protein, the coding region was subcloned into an expression vector pET-20b(+) and transformed into E. coli C41(DE3). The recombinant His6-tagged TcmonoGrx was overexpressed and purified by Ni(2+)-nitrilotriacetic acid Sepharose. The purified enzyme showed a predominant band on 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited glutathione reductase (GR) activity via dithionitrobenzoate (DTNB) assay. The Michaelis constant (K(M)) values for GSSG and NADPH were 0.064 and 0.041 mM, respectively. The enzyme's half-life of deactivation at 60 °C was 10.5 min, and its thermal inactivation rate constant (k(d)) was 5.37 × 10(-2) min(-1). The enzyme was active under a broad pH range from 6 to 8. The enzyme retained 50% activity after trypsin digestion at 37 °C for 40 min. Both mutants C(40)→S(40) and C(165)→S(165) lost 40-50% GR activity, whereas the mutant S(168)→C(168) showed a 20% increase in its GR activity.
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Affiliation(s)
- Chuian-Fu Ken
- Institute of Biotechnology, National Changhua University of Education, Changhua, Taiwan
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63
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The crystal structure of human GLRX5: iron-sulfur cluster co-ordination, tetrameric assembly and monomer activity. Biochem J 2011; 433:303-11. [PMID: 21029046 DOI: 10.1042/bj20101286] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human GLRX5 (glutaredoxin 5) is an evolutionarily conserved thiol-disulfide oxidoreductase that has a direct role in the maintenance of normal cytosolic and mitochondrial iron homoeostasis, and its expression affects haem biosynthesis and erythropoiesis. We have crystallized the human GLRX5 bound to two [2Fe-2S] clusters and four GSH molecules. The crystal structure revealed a tetrameric organization with the [2Fe-2S] clusters buried in the interior and shielded from the solvent by the conserved β1-α2 loop, Phe⁶⁹ and the GSH molecules. Each [2Fe-2S] cluster is ligated by the N-terminal activesite cysteine (Cys⁶⁷) thiols contributed by two protomers and two cysteine thiols from two GSH. The two subunits co-ordinating the cluster are in a more extended conformation compared with iron-sulfur-bound human GLRX2, and the intersubunit interactions are more extensive and involve conserved residues among monothiol GLRXs. Gel-filtration chromatography and analytical ultracentrifugation support a tetrameric organization of holo-GLRX5, whereas the apoprotein is monomeric. MS analyses revealed glutathionylation of the cysteine residues in the absence of the [2Fe-2S] cluster, which would protect them from further oxidation and possibly facilitate cluster transfer/acceptance. Apo-GLRX5 reduced glutathione mixed disulfides with a rate 100 times lower than did GLRX2 and was active as a glutathione-dependent electron donor for mammalian ribonucleotide reductase.
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Bolstad HM, Botelho DJ, Wood MJ. Proteomic analysis of protein-protein interactions within the Cysteine Sulfinate Desulfinase Fe-S cluster biogenesis system. J Proteome Res 2010; 9:5358-69. [PMID: 20734996 DOI: 10.1021/pr1006087] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fe-S cluster biogenesis is of interest to many fields, including bioenergetics and gene regulation. The CSD system is one of three Fe-S cluster biogenesis systems in E. coli and is comprised of the cysteine desulfurase CsdA, the sulfur acceptor protein CsdE, and the E1-like protein CsdL. The biological role, biochemical mechanism, and protein targets of the system remain uncharacterized. Here we present that the active site CsdE C61 has a lowered pK(a) value of 6.5, which is nearly identical to that of C51 in the homologous SufE protein and which is likely critical for its function. We observed that CsdE forms disulfide bonds with multiple proteins and identified the proteins that copurify with CsdE. The identification of Fe-S proteins and both putative and established Fe-S cluster assembly (ErpA, glutaredoxin-3, glutaredoxin-4) and sulfur trafficking (CsdL, YchN) proteins supports the two-pathway model, in which the CSD system is hypothesized to synthesize both Fe-S clusters and other sulfur-containing cofactors. We suggest that the identified Fe-S cluster assembly proteins may be the scaffold and/or shuttle proteins for the CSD system. By comparison with previous analysis of SufE, we demonstrate that there is some overlap in the CsdE and SufE interactomes.
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Affiliation(s)
- Heather M Bolstad
- Department of Environmental Toxicology, University of California, Davis, California 95616, USA
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Li L, Cheng N, Hirschi KD, Wang X. Structure of Arabidopsis chloroplastic monothiol glutaredoxin AtGRXcp. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:725-32. [PMID: 20516625 PMCID: PMC2879357 DOI: 10.1107/s0907444910013119] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 04/08/2010] [Indexed: 01/13/2023]
Abstract
The structure of Arabidopsis monothiol glutaredoxin AtGRXcp has been determined and reveals unique structural features of monothiol glutaredoxins, key residues for their interaction with glutathione and structural determinants for their distinct biochemical properties. Monothiol glutaredoxins (Grxs) play important roles in maintaining redox homeostasis in living cells and are conserved across species. Arabidopsis thaliana monothiol glutaredoxin AtGRXcp is critical for protection from oxidative stress in chloroplasts. The crystal structure of AtGRXcp has been determined at 2.4 Å resolution. AtGRXcp has a glutaredoxin/thioredoxin-like fold with distinct structural features that differ from those of dithiol Grxs. The structure reveals that the putative active-site motif CGFS is well defined and is located on the molecular surface and that a long groove extends to both sides of the catalytic Cys97. Structural comparison and molecular modeling suggest that glutathione can bind in this groove and form extensive interactions with conserved charged residues including Lys89, Arg126 and Asp152. Further comparative studies reveal that a unique loop with five additional residues adjacent to the active-site motif may be a key structural feature of monothiol Grxs and may influence their function. This study provides the first structural information on plant CGFS-type monothiol Grxs, allowing a better understanding of the redox-regulation mechanism mediated by these plant Grxs.
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Affiliation(s)
- Lenong Li
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
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66
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Gao XH, Zaffagnini M, Bedhomme M, Michelet L, Cassier-Chauvat C, Decottignies P, Lemaire SD. Biochemical characterization of glutaredoxins fromChlamydomonas reinhardtii: Kinetics and specificity in deglutathionylation reactions. FEBS Lett 2010; 584:2242-8. [DOI: 10.1016/j.febslet.2010.04.034] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/09/2010] [Accepted: 04/12/2010] [Indexed: 10/19/2022]
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67
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Ziemann M, Bhave M, Zachgo S. Bioinformatic studies of the wheat glutaredoxin gene family and functional analysis of the ROXY1 orthologues. FUNCTIONAL PLANT BIOLOGY : FPB 2010; 38:25-34. [PMID: 32480859 DOI: 10.1071/fp10185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Accepted: 10/28/2010] [Indexed: 06/11/2023]
Abstract
CC-type glutaredoxins comprise a large land plant-specific class of oxidoreductases. Previous research shows roles for two such proteins in developmental processes in Arabidopsis; ROXY1 mediates petal initiation and morphogenesis, and ROXY1 and ROXY2 are required for normal anther development. In the present work, the broader glutaredoxin family was investigated in hexaploid wheat with bioinformatic methods, revealing a large and multifunctional gene family. With a PCR based method, three wheat ROXY homeoalleles were isolated. Complementation analyses show that these three isoforms fully complemented the roxy1 mutation in Arabidopsis. Further, yeast two-hybrid experiments demonstrate that one such wheat ROXY protein interacts strongly with TGA3, an Arabidopsis TGA transcription factor previously shown to associate with ROXY1. Deletion analyses show that TaROXY-α3 docks to a glutamine rich region of TGA3, a putative transcriptional activation domain. These results suggest a conserved molecular role of Arabidopsis and wheat ROXY proteins in inflorescence/spike development, most likely in the post-translational regulation of TGA proteins including HBP-1b (the wheat PERIANTHIA orthologue), which likely exerts also a developmental function by activating histone gene transcription in highly proliferating tissues such as the SAM and root tip.
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Affiliation(s)
- Mark Ziemann
- Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, Hawthorn, Vic. 3122, Australia
| | - Mrinal Bhave
- Environment and Biotechnology Centre, Faculty of Life and Social Sciences, Swinburne University of Technology, Hawthorn, Vic. 3122, Australia
| | - Sabine Zachgo
- Department of Botany, University of Osnabrück, 49076 Osnabrück, Germany
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68
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Meyer Y, Buchanan BB, Vignols F, Reichheld JP. Thioredoxins and glutaredoxins: unifying elements in redox biology. Annu Rev Genet 2009; 43:335-67. [PMID: 19691428 DOI: 10.1146/annurev-genet-102108-134201] [Citation(s) in RCA: 332] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Since their discovery as a substrate for ribonucleotide reductase (RNR), the role of thioredoxin (Trx) and glutaredoxin (Grx) has been largely extended through their regulatory function. Both proteins act by changing the structure and activity of a broad spectrum of target proteins, typically by modifying redox status. Trx and Grx are members of families with multiple and partially redundant genes. The number of genes clearly increased with the appearance of multicellular organisms, in part because of new types of Trx and Grx with orthologs throughout the animal and plant kingdoms. The function of Trx and Grx also broadened as cells achieved increased complexity, especially in the regulation arena. In view of these progressive changes, the ubiquitous distribution of Trx and the wide occurrence of Grx enable these proteins to serve as indicators of the evolutionary history of redox regulation. In so doing, they add a unifying element that links the diverse forms of life to one another in an uninterrupted continuum. It is anticipated that future research will embellish this continuum and further elucidate the properties of these proteins and their impact on biology. The new information will be important not only to our understanding of the role of Trx and Grx in fundamental cell processes but also to future societal benefits as the proteins find new applications in a range of fields.
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Affiliation(s)
- Yves Meyer
- Université de Perpignan, Génome et dévelopement des plantes, CNRS-UP-IRD UMR 5096, F 66860 Perpignan Cedex, France.
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69
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An atlas of the thioredoxin fold class reveals the complexity of function-enabling adaptations. PLoS Comput Biol 2009; 5:e1000541. [PMID: 19851441 PMCID: PMC2757866 DOI: 10.1371/journal.pcbi.1000541] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 09/21/2009] [Indexed: 01/08/2023] Open
Abstract
The group of proteins that contain a thioredoxin (Trx) fold is huge and diverse. Assessment of the variation in catalytic machinery of Trx fold proteins is essential in providing a foundation for understanding their functional diversity and predicting the function of the many uncharacterized members of the class. The proteins of the Trx fold class retain common features-including variations on a dithiol CxxC active site motif-that lead to delivery of function. We use protein similarity networks to guide an analysis of how structural and sequence motifs track with catalytic function and taxonomic categories for 4,082 representative sequences spanning the known superfamilies of the Trx fold. Domain structure in the fold class is varied and modular, with 2.8% of sequences containing more than one Trx fold domain. Most member proteins are bacterial. The fold class exhibits many modifications to the CxxC active site motif-only 56.8% of proteins have both cysteines, and no functional groupings have absolute conservation of the expected catalytic motif. Only a small fraction of Trx fold sequences have been functionally characterized. This work provides a global view of the complex distribution of domains and catalytic machinery throughout the fold class, showing that each superfamily contains remnants of the CxxC active site. The unifying context provided by this work can guide the comparison of members of different Trx fold superfamilies to gain insight about their structure-function relationships, illustrated here with the thioredoxins and peroxiredoxins.
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70
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Bedhomme M, Zaffagnini M, Marchand CH, Gao XH, Moslonka-Lefebvre M, Michelet L, Decottignies P, Lemaire SD. Regulation by glutathionylation of isocitrate lyase from Chlamydomonas reinhardtii. J Biol Chem 2009; 284:36282-36291. [PMID: 19847013 DOI: 10.1074/jbc.m109.064428] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Post-translational modification of protein cysteine residues is emerging as an important regulatory and signaling mechanism. We have identified numerous putative targets of redox regulation in the unicellular green alga Chlamydomonas reinhardtii. One enzyme, isocitrate lyase (ICL), was identified both as a putative thioredoxin target and as an S-thiolated protein in vivo. ICL is a key enzyme of the glyoxylate cycle that allows growth on acetate as a sole source of carbon. The aim of the present study was to clarify the molecular mechanism of the redox regulation of Chlamydomonas ICL using a combination of biochemical and biophysical methods. The results clearly show that purified C. reinhardtii ICL can be inactivated by glutathionylation and reactivated by glutaredoxin, whereas thioredoxin does not appear to regulate ICL activity, and no inter- or intramolecular disulfide bond could be formed under any of the conditions tested. Glutathionylation of the protein was investigated by mass spectrometry analysis, Western blotting, and site-directed mutagenesis. The enzyme was found to be protected from irreversible oxidative inactivation by glutathionylation of its catalytic Cys(178), whereas a second residue, Cys(247), becomes artifactually glutathionylated after prolonged incubation with GSSG. The possible functional significance of this post-translational modification of ICL in Chlamydomonas and other organisms is discussed.
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Affiliation(s)
- Mariette Bedhomme
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France
| | - Mirko Zaffagnini
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France
| | - Christophe H Marchand
- Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619, CNRS/Université Paris-Sud, Bâtiment 430, 91405 Orsay, Cedex, France
| | - Xing-Huang Gao
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France
| | - Mathieu Moslonka-Lefebvre
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France
| | - Laure Michelet
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France
| | - Paulette Decottignies
- Institut de Biochimie et Biophysique Moléculaire et Cellulaire, UMR 8619, CNRS/Université Paris-Sud, Bâtiment 430, 91405 Orsay, Cedex, France
| | - Stéphane D Lemaire
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud, Bâtiment 630, 91405 Orsay, Cedex, France.
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71
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Couturier J, Jacquot JP, Rouhier N. Evolution and diversity of glutaredoxins in photosynthetic organisms. Cell Mol Life Sci 2009; 66:2539-57. [PMID: 19506802 PMCID: PMC11115520 DOI: 10.1007/s00018-009-0054-y] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 05/06/2009] [Accepted: 05/19/2009] [Indexed: 01/02/2023]
Abstract
The genome sequencing of prokaryotic and eukaryotic photosynthetic organisms enables a comparative genomic study of the glutaredoxin (Grx) family. The analysis of 58 genomes, using a specific motif composed of the active site sequence and of amino acids involved in glutathione binding, led to an updated classification of Grxs into six classes. Only two classes (I and II) are common to all photosynthetic organisms. Eukaryotes and cyanobacteria have two specific Grx classes (classes III and IV and classes V and VI, respectively). The classes IV, V and VI have not yet been identified and contain multimodular Grx fusions. In addition, putative Grx partners were identified from the presence of fusion proteins, the conservation of gene order in bacterial operons, and the gene co-occurrence. The genes encoding class II Grxs and BolA/YrbA proteins are frequently adjacent, in the same transcriptional orientation in prokaryote genomes and present in the same organisms.
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Affiliation(s)
- Jérémy Couturier
- Interactions Arbres Microorganismes, IFR 110 Génomique Ecophysiologie et Ecologie Fonctionnelles, Unité Mixte de Recherches 1136 INRA-Nancy Université, 54506 Vandoeuvre-lès-Nancy Cedex, France
| | - Jean-Pierre Jacquot
- Interactions Arbres Microorganismes, IFR 110 Génomique Ecophysiologie et Ecologie Fonctionnelles, Unité Mixte de Recherches 1136 INRA-Nancy Université, 54506 Vandoeuvre-lès-Nancy Cedex, France
| | - Nicolas Rouhier
- Interactions Arbres Microorganismes, IFR 110 Génomique Ecophysiologie et Ecologie Fonctionnelles, Unité Mixte de Recherches 1136 INRA-Nancy Université, 54506 Vandoeuvre-lès-Nancy Cedex, France
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72
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Jacquot JP, Eklund H, Rouhier N, Schürmann P. Structural and evolutionary aspects of thioredoxin reductases in photosynthetic organisms. TRENDS IN PLANT SCIENCE 2009; 14:336-43. [PMID: 19446492 DOI: 10.1016/j.tplants.2009.03.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2009] [Revised: 03/27/2009] [Accepted: 03/31/2009] [Indexed: 05/24/2023]
Abstract
Thioredoxins (Trxs) are small oxidoreductases that are involved in redox homeostasis and are found in large numbers in the subcellular compartments of eukaryotic plant cells, including the chloroplasts. Also present in chloroplasts are two forms of thioredoxin reductase (TR), which use either NADPH or ferredoxin as an electron donor. In other compartments, two additional TR forms also use NADPH: one is distributed in all photosynthetic organisms and is similar to prokaryotic enzymes, whereas the other is restricted to algae and is similar to mammalian selenoproteins. Here, we review current knowledge of the different forms of TRs across organisms and discuss the possible evolutionary fate of this class of enzymes, which provide an example of convergent functional evolution.
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Affiliation(s)
- Jean-Pierre Jacquot
- Interactions Arbres Microorganismes UMR 1136, IFR 110, Nancy University, BP 239, 54506 Vandoeuvre Cedex, France.
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73
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Gallogly MM, Starke DW, Mieyal JJ. Mechanistic and kinetic details of catalysis of thiol-disulfide exchange by glutaredoxins and potential mechanisms of regulation. Antioxid Redox Signal 2009; 11:1059-81. [PMID: 19119916 PMCID: PMC2842129 DOI: 10.1089/ars.2008.2291] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Glutaredoxins are small, heat-stable proteins that exhibit a characteristic thioredoxin fold and a CXXC/S active-site motif. A variety of glutathione (GSH)-dependent catalytic activities have been attributed to the glutaredoxins, including reduction of ribonucleotide reductase, arsenate, and dehydroascorbate; assembly of iron sulfur cluster complexes; and protein glutathionylation and deglutathionylation. Catalysis of reversible protein glutathionylation by glutaredoxins has been implicated in regulation of redox signal transduction and sulfhydryl homeostasis in numerous contexts in health and disease. This forum review is presented in two parts. Part I is focused primarily on the mechanism of the deglutathionylation reaction catalyzed by prototypical dithiol glutaredoxins, especially human Grx1 and Grx2. Grx-catalyzed protein deglutathionylation proceeds by a nucleophilic, double-displacement mechanism in which rate enhancement is attributed to special reactivity of the low pK(a) cysteine at its active site, and to increased nucleophilicity of the second substrate, GSH. Glutaredoxins (and Grx domains) have been identified in most organisms, and many exhibit deglutathionylation or other activities or both. Further characterization according to glutathionyl selectivity, physiological substrates, and intracellular roles may lead to subclassification of this family of enzymes. Part II presents potential mechanisms for in vivo regulation of Grx activity, providing avenues for future studies.
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Affiliation(s)
- Molly M Gallogly
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106-4965, USA
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74
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Couturier J, Koh CS, Zaffagnini M, Winger AM, Gualberto JM, Corbier C, Decottignies P, Jacquot JP, Lemaire SD, Didierjean C, Rouhier N. Structure-function relationship of the chloroplastic glutaredoxin S12 with an atypical WCSYS active site. J Biol Chem 2009; 284:9299-310. [PMID: 19158074 PMCID: PMC2666582 DOI: 10.1074/jbc.m807998200] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 01/16/2009] [Indexed: 01/08/2023] Open
Abstract
Glutaredoxins (Grxs) are efficient catalysts for the reduction of mixed disulfides in glutathionylated proteins, using glutathione or thioredoxin reductases for their regeneration. Using GFP fusion, we have shown that poplar GrxS12, which possesses a monothiol (28)WCSYS(32) active site, is localized in chloroplasts. In the presence of reduced glutathione, the recombinant protein is able to reduce in vitro substrates, such as hydroxyethyldisulfide and dehydroascorbate, and to regenerate the glutathionylated glyceraldehyde-3-phosphate dehydrogenase. Although the protein possesses two conserved cysteines, it is functioning through a monothiol mechanism, the conserved C terminus cysteine (Cys(87)) being dispensable, since the C87S variant is fully active in all activity assays. Biochemical and crystallographic studies revealed that Cys(87) exhibits a certain reactivity, since its pK(a) is around 5.6. Coupled with thiol titration, fluorescence, and mass spectrometry analyses, the resolution of poplar GrxS12 x-ray crystal structure shows that the only oxidation state is a glutathionylated derivative of the active site cysteine (Cys(29)) and that the enzyme does not form inter- or intramolecular disulfides. Contrary to some plant Grxs, GrxS12 does not incorporate an iron-sulfur cluster in its wild-type form, but when the active site is mutated into YCSYS, it binds a [2Fe-2S] cluster, indicating that the single Trp residue prevents this incorporation.
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Affiliation(s)
- Jeremy Couturier
- Unité Mixte de Recherches 1136 UHP-INRA Interaction Arbres-Microorganismes, IFR 110 GEEF, Nancy Université, Faculté des Sciences, 54506 Vandoeuvre Cedex, France
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75
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The glutathione/glutaredoxin system is essential for arsenate reduction in Synechocystis sp. strain PCC 6803. J Bacteriol 2009; 191:3534-43. [PMID: 19304854 DOI: 10.1128/jb.01798-08] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Arsenic resistance in Synechocystis sp. strain PCC 6803 is mediated by an operon of three genes in which arsC codes for an arsenate reductase with unique characteristics. Here we describe the identification of two additional and nearly identical genes coding for arsenate reductases in Synechocystis sp. strain PCC 6803, which we have designed arsI1 and arsI2, and the biochemical characterization of both ArsC (arsenate reductase) and ArsI. Functional analysis of single, double, and triple mutants shows that both ArsI enzymes are active arsenate reductases but that their roles in arsenate resistance are essential only in the absence of ArsC. Based on its biochemical properties, ArsC belongs to a family that, though related to thioredoxin-dependent arsenate reductases, uses the glutathione/glutaredoxin system for reduction, whereas ArsI belongs to the previously known glutaredoxin-dependent family. We have also analyzed the role in arsenate resistance of the three glutaredoxins present in Synechocystis sp. strain PCC 6803 both in vitro and in vivo. Only the dithiolic glutaredoxins, GrxA (glutaredoxin A) and GrxB (glutaredoxin B), are able to donate electrons to both types of reductases in vitro, while GrxC (glutaredoxin C), a monothiolic glutaredoxin, is unable to donate electrons to either type. Analysis of glutaredoxin mutant strains revealed that only those lacking the grxA gene have impaired arsenic resistance.
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76
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Gao XH, Bedhomme M, Veyel D, Zaffagnini M, Lemaire SD. Methods for analysis of protein glutathionylation and their application to photosynthetic organisms. MOLECULAR PLANT 2009; 2:218-35. [PMID: 19825609 DOI: 10.1093/mp/ssn072] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Protein S-glutathionylation, the reversible formation of a mixed-disulfide between glutathione and protein thiols, is involved in protection of protein cysteines from irreversible oxidation, but also in protein redox regulation. Recent studies have implicated S-glutathionylation as a cellular response to oxidative/nitrosative stress, likely playing an important role in signaling. Considering the potential importance of glutathionylation, a number of methods have been developed for identifying proteins undergoing glutathionylation. These methods, ranging from analysis of purified proteins in vitro to large-scale proteomic analyses in vivo, allowed identification of nearly 200 targets in mammals. By contrast, the number of known glutathionylated proteins is more limited in photosynthetic organisms, although they are severely exposed to oxidative stress. The aim of this review is to detail the methods available for identification and analysis of glutathionylated proteins in vivo and in vitro. The advantages and drawbacks of each technique will be discussed as well as their application to photosynthetic organisms. Furthermore, an overview of known glutathionylated proteins in photosynthetic organisms is provided and the physiological importance of this post-translational modification is discussed.
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Affiliation(s)
- Xing-Huang Gao
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/Université Paris-Sud 11, Bâtiment 630, Orsay 91405, Cedex, France
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77
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Butland G, Babu M, Díaz-Mejía JJ, Bohdana F, Phanse S, Gold B, Yang W, Li J, Gagarinova AG, Pogoutse O, Mori H, Wanner BL, Lo H, Wasniewski J, Christopolous C, Ali M, Venn P, Safavi-Naini A, Sourour N, Caron S, Choi JY, Laigle L, Nazarians-Armavil A, Deshpande A, Joe S, Datsenko KA, Yamamoto N, Andrews BJ, Boone C, Ding H, Sheikh B, Moreno-Hagelseib G, Greenblatt JF, Emili A. eSGA: E. coli synthetic genetic array analysis. Nat Methods 2009; 5:789-95. [PMID: 18677321 DOI: 10.1038/nmeth.1239] [Citation(s) in RCA: 188] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Accepted: 06/19/2008] [Indexed: 12/24/2022]
Abstract
Physical and functional interactions define the molecular organization of the cell. Genetic interactions, or epistasis, tend to occur between gene products involved in parallel pathways or interlinked biological processes. High-throughput experimental systems to examine genetic interactions on a genome-wide scale have been devised for Saccharomyces cerevisiae, Schizosaccharomyces pombe, Caenorhabditis elegans and Drosophila melanogaster, but have not been reported previously for prokaryotes. Here we describe the development of a quantitative screening procedure for monitoring bacterial genetic interactions based on conjugation of Escherichia coli deletion or hypomorphic strains to create double mutants on a genome-wide scale. The patterns of synthetic sickness and synthetic lethality (aggravating genetic interactions) we observed for certain double mutant combinations provided information about functional relationships and redundancy between pathways and enabled us to group bacterial gene products into functional modules.
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Affiliation(s)
- Gareth Butland
- Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto M5S 3E1, Canada
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78
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Eckers E, Bien M, Stroobant V, Herrmann JM, Deponte M. Biochemical Characterization of Dithiol Glutaredoxin 8 from Saccharomyces cerevisiae: The Catalytic Redox Mechanism Redux. Biochemistry 2009; 48:1410-23. [DOI: 10.1021/bi801859b] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Elisabeth Eckers
- Butenandt Institute for Physiological Chemistry, Ludwig-Maximilians University, D-81377 Munich, Germany, Cell Biology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany, and Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université Catholique de Louvain, B-1200 Brussels, Belgium
| | - Melanie Bien
- Butenandt Institute for Physiological Chemistry, Ludwig-Maximilians University, D-81377 Munich, Germany, Cell Biology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany, and Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université Catholique de Louvain, B-1200 Brussels, Belgium
| | - Vincent Stroobant
- Butenandt Institute for Physiological Chemistry, Ludwig-Maximilians University, D-81377 Munich, Germany, Cell Biology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany, and Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université Catholique de Louvain, B-1200 Brussels, Belgium
| | - Johannes M. Herrmann
- Butenandt Institute for Physiological Chemistry, Ludwig-Maximilians University, D-81377 Munich, Germany, Cell Biology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany, and Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université Catholique de Louvain, B-1200 Brussels, Belgium
| | - Marcel Deponte
- Butenandt Institute for Physiological Chemistry, Ludwig-Maximilians University, D-81377 Munich, Germany, Cell Biology, University of Kaiserslautern, D-67663 Kaiserslautern, Germany, and Ludwig Institute for Cancer Research and Cellular Genetics Unit, Université Catholique de Louvain, B-1200 Brussels, Belgium
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79
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Protein S-glutathionylation: a regulatory device from bacteria to humans. Trends Biochem Sci 2009; 34:85-96. [PMID: 19135374 DOI: 10.1016/j.tibs.2008.11.002] [Citation(s) in RCA: 474] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 11/19/2008] [Accepted: 11/20/2008] [Indexed: 01/25/2023]
Abstract
S-Glutathionylation is the specific post-translational modification of protein cysteine residues by the addition of the tripeptide glutathione, the most abundant and important low-molecular-mass thiol within most cell types. Protein S-glutathionylation is promoted by oxidative or nitrosative stress but also occurs in unstressed cells. It can serve to regulate a variety of cellular processes by modulating protein function and to prevent irreversible oxidation of protein thiols. Recent findings support an essential role for S-glutathionylation in the control of cell-signalling pathways associated with viral infections and with tumour necrosis factor-(-induced apoptosis. Glyceraldehyde-3-phosphate dehydrogenase has recently been implicated in the regulation of endothelin-1 synthesis by a novel, S-glutathionylation-based mechanism involving messenger RNA stability. Moreover, recent studies have identified S-glutathionylation as a redox signalling mechanism in plants.
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80
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Kalinina EV, Chernov NN, Saprin AN. Involvement of thio-, peroxi-, and glutaredoxins in cellular redox-dependent processes. BIOCHEMISTRY (MOSCOW) 2009; 73:1493-510. [DOI: 10.1134/s0006297908130099] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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81
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Marteyn B, Domain F, Legrain P, Chauvat F, Cassier-Chauvat C. The thioredoxin reductase-glutaredoxins-ferredoxin crossroad pathway for selenate tolerance in Synechocystis PCC6803. Mol Microbiol 2008; 71:520-32. [PMID: 19040637 DOI: 10.1111/j.1365-2958.2008.06550.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Most organisms use two systems to maintain the redox homeostasis of cellular thiols. In the thioredoxin (Trx) system, NADPH sequentially reduces thioredoxin reductases (NTR), Trxs and protein disulfides. In the glutaredoxin (Grx) system, NADPH reduces the glutathione reductase enzyme occurring in most organisms, glutathione, Grxs, and protein disulfides or glutathione-protein mixed disulfides. As little is known concerning these enzymes in cyanobacteria, we have undertaken their analysis in the model strain Synechocystis PCC6803. We found that Grx1 and Grx2 are active, and that Grx2 but not Grx1 is crucial to tolerance to hydrogen peroxide and selenate. We also found that Synechocystis has no genuine glutathione reductase and uses NTR as a Grx electron donor, in a novel integrative pathway NADPH-NTR-Grx1-Grx2-Fed7 (ferredoxin 7), which operates in protection against selenate, the predominant form of selenium in the environment. This is the first report on the occurrence of a physical interaction between a Grx and a Fed, and of an electron transfer between two Grxs. These findings are discussed in terms of the (i) selectivity of Grxs and Feds (Synechocystis possesses nine Feds), (ii) crucial importance of NTR for cell fitness and (iii) resistance to selenate, in absence of a Thauera selenatis-like selenate reductase.
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Affiliation(s)
- Benoit Marteyn
- CEA, iBiTec-S, SBIGeM, LBI, Bat 142 CEA-Saclay, F-91191 Gif sur Yvette Cedex, France
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82
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Herrero E, Ros J, Bellí G, Cabiscol E. Redox control and oxidative stress in yeast cells. Biochim Biophys Acta Gen Subj 2008; 1780:1217-35. [DOI: 10.1016/j.bbagen.2007.12.004] [Citation(s) in RCA: 292] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 11/29/2007] [Accepted: 12/07/2007] [Indexed: 12/21/2022]
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83
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Lillig CH, Berndt C, Holmgren A. Glutaredoxin systems. Biochim Biophys Acta Gen Subj 2008; 1780:1304-17. [DOI: 10.1016/j.bbagen.2008.06.003] [Citation(s) in RCA: 416] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 06/11/2008] [Accepted: 06/11/2008] [Indexed: 12/15/2022]
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84
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Comini MA, Rettig J, Dirdjaja N, Hanschmann EM, Berndt C, Krauth-Siegel RL. Monothiol Glutaredoxin-1 Is an Essential Iron-Sulfur Protein in the Mitochondrion of African Trypanosomes. J Biol Chem 2008; 283:27785-27798. [DOI: 10.1074/jbc.m802010200] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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85
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Mostertz J, Hochgräfe F, Jürgen B, Schweder T, Hecker M. The role of thioredoxin TrxA in Bacillus subtilis: a proteomics and transcriptomics approach. Proteomics 2008; 8:2676-90. [PMID: 18601268 DOI: 10.1002/pmic.200701015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Thiol-disulfide oxidoreductases of the thioredoxin superfamily are crucial for maintaining the thiol redox state in living organisms. For the bacterium Bacillus subtilis thioredoxin A (TrxA) was described as the product of an essential gene indicating a key role during growth. By means of mRNA profiling Smits et al. (J. Bacteriol. 2005, 187, 3921-3930) suggested a critical function for TrxA in sulfur utilization during stationary phase. We extended the analysis of TrxA to exponential growth and characterized a trxA conditional mutant by proteome analysis complemented by transcriptomics. After TrxA-depletion, the growth rate was dramatically decreased. The cells responded at mRNA and protein level by the increased expression of genes involved in the utilization of sulfur, which represents the most obvious response as visualized by gel-based proteomics. Furthermore, several genes of the antioxidant response were found at higher expression levels after TrxA-depletion. When sulfate was replaced by thiosulfate or methionine as sulfur source, the growth inhibition was abolished. In the presence of thiosulfate but in the absence of TrxA, the induction of the sulfur limitation response and the oxidative stress response was not observed. Our results show that the global change of gene expression is primarily caused by the interruption of the sulfate utilization after TrxA depletion. Thus, its function in sulfate assimilation renders TrxA an essential protein in growing B. subtilis cells.
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Affiliation(s)
- Jörg Mostertz
- Institute of Microbiology, Ernst-Moritz-Arndt-University Greifswald, Greifswald, Germany.
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86
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Abstract
The higher affinity of Cd(2+) for sulfur compounds than for nitrogen and oxygen led to the theoretical consideration that cadmium toxicity should result mainly from the binding of Cd(2+) to sulfide, thiol groups, and sulfur-rich complex compounds rather than from Cd(2+) replacement of transition-metal cations from nitrogen- or oxygen-rich biological compounds. This hypothesis was tested by using Escherichia coli for a global transcriptome analysis of cells synthesizing glutathione (GSH; wild type), gamma-glutamylcysteine (DeltagshB mutant), or neither of the two cellular thiols (DeltagshA mutant). The resulting data, some of which were validated by quantitative reverse transcription-PCR, were sorted using the KEGG (Kyoto Encyclopedia of Genes and Genomes) orthology system, which groups genes hierarchically with respect to the cellular functions of their respective products. The main difference among the three strains concerned tryptophan biosynthesis, which was up-regulated in wild-type cells upon cadmium shock and strongly up-regulated in DeltagshA cells but repressed in DeltagshB cells containing gamma-glutamylcysteine instead of GSH. Overall, however, all three E. coli strains responded to cadmium shock similarly, with the up-regulation of genes involved in protein, disulfide bond, and oxidative damage repair; cysteine and iron-sulfur cluster biosynthesis; the production of proteins containing sensitive iron-sulfur clusters; the storage of iron; and the detoxification of Cd(2+) by efflux. General energy conservation pathways and iron uptake were down-regulated. These findings indicated that the toxic action of Cd(2+) indeed results from the binding of the metal cation to sulfur, lending support to the hypothesis tested.
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87
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Abstract
Glutathione (GSH) and its derivative phytochelatin are important binding factors in transition-metal homeostasis in many eukaryotes. Here, we demonstrate that GSH is also involved in chromate, Zn(II), Cd(II), and Cu(II) homeostasis and resistance in Escherichia coli. While the loss of the ability to synthesize GSH influenced metal tolerance in wild-type cells only slightly, GSH was important for residual metal resistance in cells without metal efflux systems. In mutant cells without the P-type ATPase ZntA, the additional deletion of the GSH biosynthesis system led to a strong decrease in resistance to Cd(II) and Zn(II). Likewise, in mutant cells without the P-type ATPase CopA, the removal of GSH led to a strong decrease of Cu(II) resistance. The precursor of GSH, gamma-glutamylcysteine (gammaEC), was not able to compensate for a lack of GSH. On the contrary, gammaEC-containing cells were less copper and cadmium tolerant than cells that contained neither gammaEC nor GSH. Thus, GSH may play an important role in trace-element metabolism not only in higher organisms but also in bacteria.
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88
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Vlamis-Gardikas A. The multiple functions of the thiol-based electron flow pathways of Escherichia coli: Eternal concepts revisited. Biochim Biophys Acta Gen Subj 2008; 1780:1170-200. [PMID: 18423382 DOI: 10.1016/j.bbagen.2008.03.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Revised: 03/18/2008] [Accepted: 03/22/2008] [Indexed: 10/22/2022]
Abstract
Electron flow via thiols is a theme with many variations in all kingdoms of life. The favourable physichochemical properties of the redox active couple of two cysteines placed in the optimised environment of the thioredoxin fold allow for two electron transfers in between top biological reductants and ultimate oxidants. The reduction of ribonucleotide reductases by thioredoxin and thioredoxin reductase of Escherichia coli (E. coli) was one of the first pathways to be elucidated. Diverse functions such as protein folding in the periplasm, maturation of respiratory enzymes, detoxification of hydrogen peroxide and prevention of oxidative damage may be based on two electron transfers via thiols. A growing field is the relation of thiol reducing pathways and the interaction of E. coli with different organisms. This concept combined with the sequencing of the genomes of different bacteria may allow for the identification of fine differences in the systems employing thiols for electron flow between pathogens and their corresponding mammalian hosts. The emerging possibility is the development of novel antibiotics.
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Affiliation(s)
- Alexios Vlamis-Gardikas
- Center of Basic Research I-Biochemistry Division, Biomedical Research Foundation (BRFAA), Academy of Athens, Soranou Efessiou 4, GR-11527 Athens, Greece.
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89
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Yamamoto Y, Ritz D, Planson AG, Jönsson TJ, Faulkner MJ, Boyd D, Beckwith J, Poole LB. Mutant AhpC peroxiredoxins suppress thiol-disulfide redox deficiencies and acquire deglutathionylating activity. Mol Cell 2008; 29:36-45. [PMID: 18206967 DOI: 10.1016/j.molcel.2007.11.029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 07/25/2007] [Accepted: 11/16/2007] [Indexed: 11/25/2022]
Abstract
The bacterial peroxiredoxin AhpC, a cysteine-dependent peroxidase, can be converted through a single amino acid insertion to a disulfide reductase, AhpC*, active in the glutathione and glutaredoxin pathway. Here we show that, whereas AhpC* is inactive as a peroxidase, other point mutants in AhpC can confer the in vivo disulfide reductase activity without abrogating peroxidase activity. Moreover, AhpC* and several point mutants tested in vitro exhibit an enhanced reductase activity toward mixed disulfides between glutathione and glutaredoxin (Grx-S-SG), consistent with the in vivo requirements for these components. Remarkably, this Grx-S-SG reductase activity relies not on the peroxidatic cysteine but rather on the resolving cysteine that plays only a secondary role in the peroxidase mechanism. Furthermore, putative conformational changes, which impart this unusual Grx-S-SG reductase activity, are transmissible across subunits. Thus, AhpC and potentially other peroxiredoxins in this widespread family can elaborate a new reductase function that alleviates disulfide stress.
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Affiliation(s)
- Yuji Yamamoto
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA
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90
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Krauth-Siegel RL, Comini MA. Redox control in trypanosomatids, parasitic protozoa with trypanothione-based thiol metabolism. Biochim Biophys Acta Gen Subj 2008; 1780:1236-48. [PMID: 18395526 DOI: 10.1016/j.bbagen.2008.03.006] [Citation(s) in RCA: 288] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 02/26/2008] [Accepted: 03/11/2008] [Indexed: 01/09/2023]
Abstract
Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH- and the thiol-based redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.
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91
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Berndt C, Lillig CH, Holmgren A. Thioredoxins and glutaredoxins as facilitators of protein folding. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1783:641-50. [PMID: 18331844 DOI: 10.1016/j.bbamcr.2008.02.003] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Revised: 02/05/2008] [Accepted: 02/06/2008] [Indexed: 12/27/2022]
Abstract
Thiol-disulfide oxidoreductase systems of bacterial cytoplasm and eukaryotic cytosol favor reducing conditions and protein thiol groups, while bacterial periplasm and eukaryotic endoplasmatic reticulum provide oxidizing conditions and a machinery for disulfide bond formation in the secretory pathway. Oxidoreductases of the thioredoxin fold superfamily catalyze steps in oxidative protein folding via protein-protein interactions and covalent catalysis to act as chaperones and isomerases of disulfides to generate a native fold. The active site dithiol/disulfide of thioredoxin fold proteins is CXXC where variations of the residues inside the disulfide ring are known to increase the redox potential like in protein disulfide isomerases. In the catalytic mechanism thioredoxin fold proteins bind to target proteins through conserved backbone-backbone hydrogen bonds and induce conformational changes of the target disulfide followed by nucleophilic attack by the N-terminally located low pK(a) Cys residue. This generates a mixed disulfide covalent bond which subsequently is resolved by attack from the C-terminally located Cys residue. This review will focus on two members of the thioredoxin superfamily of proteins known to be crucial for maintaining a reduced intracellular redox state, thioredoxin and glutaredoxin, and their potential functions as facilitators and regulators of protein folding and chaperone activity.
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Affiliation(s)
- Carsten Berndt
- The Medical Nobel Institute for Biochemistry, Karolinska Institutet, Stockholm, Sweden
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92
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Cheng NH. AtGRX4, an Arabidopsis chloroplastic monothiol glutaredoxin, is able to suppress yeast grx5 mutant phenotypes and respond to oxidative stress. FEBS Lett 2008; 582:848-54. [PMID: 18275854 DOI: 10.1016/j.febslet.2008.02.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 02/01/2008] [Accepted: 02/05/2008] [Indexed: 11/28/2022]
Abstract
Arabidopsis monothiol glutaredoxin (Grx), AtGRX4, was targeted to chloroplasts/plastids and had high similarity to yeast Grx5. In yeast expression assays, AtGRX4 localized to the mitochondria and suppressed the sensitivity of grx5 cells to oxidants. In addition, AtGRX4 reduced iron accumulation and rescued the lysine auxotrophy of grx5 cells. In planta, AtGRX4 RNA transcripts accumulated in growing tissues. Furthermore, AtGRX4expression was altered under various stresses. Genetic analysis revealed that seedlings of atgrx4 mutants were sensitive to oxidants. Taken together, these results suggest that AtGRX4 may have important functions in plant growth and development under extreme environments.
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Affiliation(s)
- Ning-Hui Cheng
- Plant Physiology Group, USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, 1100 Bates Street, Houston, TX 77030, USA.
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93
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Zaffagnini M, Michelet L, Massot V, Trost P, Lemaire SD. Biochemical characterization of glutaredoxins from Chlamydomonas reinhardtii reveals the unique properties of a chloroplastic CGFS-type glutaredoxin. J Biol Chem 2008; 283:8868-76. [PMID: 18216016 DOI: 10.1074/jbc.m709567200] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Glutaredoxins (GRXs) are small ubiquitous disulfide oxidoreductases known to use GSH as electron donor. In photosynthetic organisms, little is known about the biochemical properties of GRXs despite the existence of approximately 30 different isoforms in higher plants. We report here the biochemical characterization of Chlamydomonas GRX1 and GRX3, the major cytosolic and chloroplastic isoforms, respectively. Glutaredoxins are classified on the basis of the amino acid sequence of the active site. GRX1 is a typical CPYC-type GRX, which is reduced by GSH and exhibits disulfide reductase, dehydroascorbate reductase, and deglutathionylation activities. In contrast, GRX3 exhibits unique properties. This chloroplastic CGFS-type GRX is not reduced by GSH and has an atypically low redox potential (-323 +/- 4 mV at pH 7.9). Remarkably, GRX3 can be reduced in the light by photoreduced ferredoxin and ferredoxin-thioredoxin reductase. Both GRXs proved to be very efficient catalysts of A(4)-glyceraldehyde-3-phosphate dehydrogenase deglutathionylation, whereas cytosolic and chloroplastic thioredoxins were inefficient. Glutathionylated A(4)-glyceraldehyde-3-phosphate dehydrogenase is the first physiological substrate identified for a CGFS-type GRX.
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Affiliation(s)
- Mirko Zaffagnini
- Institut de Biotechnologie des Plantes, UMR 8618, CNRS/University of Paris-Sud 11, Bâtiment 630, Orsay 91405, Cedex, France
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94
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Cloning, functional analysis, and mitochondrial localization of Trypanosoma brucei monothiol glutaredoxin-1. Biol Chem 2008; 389:21-32. [DOI: 10.1515/bc.2007.147] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractAfrican trypanosomes encode three monothiol glutaredoxins (1-C-Grx1 to 3). 1-C-Grx1 has a putative CAYS active site and Cys181 as single additional cysteine. The recombinant protein forms non-covalent homodimers. As observed for other monothiol glutaredoxins,Trypanosoma brucei1-C-Grx1 was not active in the glutaredoxin assay with hydroxyethyl disulfide and glutathione nor catalyzed the reduction of insulin disulfide. In addition, it lacked peroxidase activity and did not catalyze protein (de)glutathionylation. Upon oxidation, 1-C-Grx1 forms an intramolecular disulfide bridge and, to a minor degree, covalent dimers. Both disulfide forms are reduced by the parasite trypanothione/tryparedoxin system. 1-C-Grx1 shows mitochondrial localization. The total cellular concentration is at least 5 μm. Thus, 1-C-Grx1 is an abundant protein especially in the rudimentary organelle of the mammalian form of the parasite. Expression of 1-C-Grx1 in Grx5-deficient yeast cells with its authentic presequence targeted the protein to the mitochondria and partially restored the growth phenotype and aconitase activity of the mutant, and conferred resistance against hydroperoxides and diamide. The parasite Grx2 and 3 failed to substitute for Grx5. This is surprising because even bacterial and plant 1-Cys-glutaredoxins efficiently revert the defects, and may be due to the lack of two basic residues conserved in all but the trypanosomatid proteins.
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95
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Toledano MB, Kumar C, Le Moan N, Spector D, Tacnet F. The system biology of thiol redox system inEscherichia coliand yeast: Differential functions in oxidative stress, iron metabolism and DNA synthesis. FEBS Lett 2007; 581:3598-607. [PMID: 17659286 DOI: 10.1016/j.febslet.2007.07.002] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Accepted: 07/02/2007] [Indexed: 11/21/2022]
Abstract
By its ability to engage in a variety of redox reactions and coordinating metals, cysteine serves as a key residue in mediating enzymatic catalysis, protein oxidative folding and trafficking, and redox signaling. The thiol redox system, which consists of the glutathione and thioredoxin pathways, uses the cysteine residue to catalyze thiol-disulfide exchange reactions, thereby controlling the redox state of cytoplasmic cysteine residues and regulating the biological functions it subserves. Here, we consider the thiol redox systems of Escherichia coli and Saccharomyces cerevisiae, emphasizing the role of genetic approaches in the understanding of the cellular functions of these systems. We show that although prokaryotic and eukaryotic systems have a similar architecture, they profoundly differ in their overall cellular functions.
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Affiliation(s)
- Michel B Toledano
- CEA, iBiTecS, Laboratoire Stress Oxydants et Cancer, Gif sur Yvette F-91191, France.
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96
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Garg SK, Suhail Alam M, Soni V, Radha Kishan KV, Agrawal P. Characterization of Mycobacterium tuberculosis WhiB1/Rv3219 as a protein disulfide reductase. Protein Expr Purif 2007; 52:422-32. [PMID: 17157031 DOI: 10.1016/j.pep.2006.10.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 10/19/2006] [Accepted: 10/23/2006] [Indexed: 11/22/2022]
Abstract
WhiB family of protein is emerging as one of the most fascinating group and is implicated in stress response as well as pathogenesis via their involvement in diverse cellular processes. Surprisingly, available in vivo data indicate an organism specific physiological role for each of these proteins. The WhiB proteins have four conserved cysteine residues where two of them are present in a C-X-X-C motif. In thioredoxins and similar proteins, this motif works as an active site and confers thiol-disulfide oxidoreductase activity to the protein. The recombinant WhiB1/Rv3219 was purified in a single step from Escherichia coli using Ni(2+)-NTA affinity chromatography and was found to exist as a homodimer. Mass spectrometry of WhiB1 shows that the four cysteine residues form two intramolecular disulfide bonds. Using intrinsic tryptophan fluorescence as a measure of redox state, the redox potential of WhiB1 was calculated as -236+/-2mV, which corresponds to the redox potential of many cytoplasmic thioredoxin-like proteins. WhiB1 catalyzed the reduction of insulin disulfide thus clearly demonstrating that it functions as a protein disulfide reductase. Present study for the first time suggests that WhiB1 may be a part of the redox network of Mycobacterium tuberculosis through its involvement in thiol-disulfide exchange with other cellular proteins.
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Affiliation(s)
- Saurabh K Garg
- Institute of Microbial Technology, Sector 39A, Chandigarh 160 036, India
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97
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Alam MS, Garg SK, Agrawal P. Molecular function of WhiB4/Rv3681c of Mycobacterium tuberculosis H37Rv: a [4Fe?4S] cluster co-ordinating protein disulphide reductase. Mol Microbiol 2007; 63:1414-31. [PMID: 17302817 DOI: 10.1111/j.1365-2958.2007.05589.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The genome sequence of Mycobacterium tuberculosis H37Rv revealed the presence of seven whiB-like open reading frames. In spite of several genetic studies on whiB genes, the biochemical properties of WhiB proteins are poorly understood. All WhiB-like proteins have four conserved cysteine residues, out of which two are present in a CXXC motif. We report for the first time the detailed biochemical and biophysical properties of M. tuberculosis WhiB4/Rv3681c and demonstrate the functional relevance of four conserved cysteines and the CXXC motif. UV-visible absorption spectra of freshly purified mWhiB4 showed the presence of a [2Fe-2S] cluster, whereas the electron paramagnetic resonance (EPR) spectra of reconstituted protein showed the presence of a [4Fe-4S] cluster. The iron-sulphur cluster was redox sensitive but stably co-ordinated to the protein even in the presence of high concentration of chaotropic agents. Despite primary sequence divergence from thioredoxin family proteins, the apo mWhiB4 has properties similar to thioredoxins and functions as a protein disulphide reductase, whereas holo mWhiB4 is enzymatically inactive. Apart from the cysteine thiol of CXXC motif the distantly placed thiol pair also contributes equally to the enzymatic activity of mWhiB4. A functional model of mWhiB4 in redox signaling during oxidative stress in M. tuberculosis has been presented.
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Affiliation(s)
- Md Suhail Alam
- Institute of Microbial Technology, Sector-39A, Chandigarh, 160 036, India
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98
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Melchers J, Dirdjaja N, Ruppert T, Krauth-Siegel RL. Glutathionylation of Trypanosomal Thiol Redox Proteins. J Biol Chem 2007; 282:8678-94. [PMID: 17242409 DOI: 10.1074/jbc.m608140200] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanosomatids, the causative agents of several tropical diseases, lack glutathione reductase and thioredoxin reductase but have a trypanothione reductase instead. The main low molecular weight thiols are trypanothione (N(1),N(8)-bis-(glutathionyl)spermidine) and glutathionyl-spermidine, but the parasites also contain free glutathione. To elucidate whether trypanosomes employ S-thiolation for regulatory or protection purposes, six recombinant parasite thiol redox proteins were studied by ESI-MS and MALDI-TOF-MS for their ability to form mixed disulfides with glutathione or glutathionylspermidine. Trypanosoma brucei mono-Cys-glutaredoxin 1 is specifically thiolated at Cys(181). Thiolation of this residue induced formation of an intramolecular disulfide bridge with the putative active site Cys(104). This contrasts with mono-Cys-glutaredoxins from other sources that have been reported to be glutathionylated at the active site cysteine. Both disulfide forms of the T. brucei protein were reduced by tryparedoxin and trypanothione, whereas glutathione cleaved only the protein disulfide. In the glutathione peroxidase-type tryparedoxin peroxidase III of T. brucei, either Cys(47) or Cys(95) became glutathionylated but not both residues in the same protein molecule. T. brucei thioredoxin contains a third cysteine (Cys(68)) in addition to the redox active dithiol/disulfide. Treatment of the reduced protein with GSSG caused glutathionylation of Cys(68), which did not affect its capacity to catalyze reduction of insulin disulfide. Reduced T. brucei tryparedoxin possesses only the redox active Cys(32)-Cys(35) couple, which upon reaction with GSSG formed a disulfide. Also glyoxalase II and Trypanosoma cruzi trypanothione reductase were not sensitive to thiolation at physiological GSSG concentrations.
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99
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Porat A, Lillig CH, Johansson C, Fernandes AP, Nilsson L, Holmgren A, Beckwith J. The reducing activity of glutaredoxin 3 toward cytoplasmic substrate proteins is restricted by methionine 43. Biochemistry 2007; 46:3366-77. [PMID: 17305371 PMCID: PMC2518409 DOI: 10.1021/bi6024353] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reducing proteins glutaredoxin 3 (Grx3) and glutaredoxin 1 (Grx1) are structurally similar but exhibit different specificities toward substrates. Grx1 efficiently reduces ribonucleotide reductase and PAPS reductase, while Grx3 reduces these enzymes inefficiently or not at all. We previously described a selection for Grx3 mutants with increased activity toward substrates of Grx1 in vivo. Remarkably, we repeatedly isolated mutants with changes in only one of the amino acids of Grx3, methionine 43, converting it to either valine, leucine, or isoleucine. In this paper we present additional genetic studies and a biochemical characterization of Grx3-Met43Val, the most efficient mutant. We show that Grx3-Met43Val is able to reduce ribonucleotide reductae and PAPS reductase much more efficiently than the wild-type protein in vitro. The altered protein has an increased Vmax over that of Grx3, nearly the same Vmax as Grx1 while the Km remains high. Molecular dynamics simulations suggest that the Met43Val substitution results in changes in properties of the N-terminal cysteine of the active site leading to a considerably lower pKa. Furthermore, Grx3-Met43Val shows an 11 mV lower redox potential than the wild-type Grx3. These findings provide biochemical and structural explanations for the increased reductive efficiency of the mutant Grx3.
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Affiliation(s)
- Amir Porat
- Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, Massachusetts 02115, USA
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100
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Abstract
Origami is the Japanese art of folding a piece of paper into complex shapes and forms. Much like origami of paper, Nature has used conserved protein folds to engineer proteins for a particular task. An example of a protein family, which has been used by Nature numerous times, is the thioredoxin superfamily. Proteins in the thioredoxin superfamily are all structured with a beta-sheet core surrounded with alpha-helices, and most contain a canonical CXXC motif. The remarkable feature of these proteins is that the link between them is the fold; however, their reactivity is different for each member due to small variations in this general fold as well as their active site. This review attempts to unravel the minute differences within this protein family, and it also demonstrates the ingenuity of Nature to use a conserved fold to generate a diverse collection of proteins to perform a number of different biochemical tasks.
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Affiliation(s)
- Jonathan L Pan
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
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