|Gene:||gor||Accession Numbers: EG10412 (MetaCyc), b3500, ECK3485|
Species: Escherichia coli K-12 substr. MG1655
Subunit composition of
glutathione reductase = [Gor]2
glutathione reductase (NADPH) = Gor
Glutathione reductase (Gor) is a flavoprotein that reduces oxidized glutathione to form reduced glutathione (GSH), the major nonprotein sulfhydryl in living organisms. Glutathione takes part in many different intracellular processes, including maintenance of reduced thiol groups, protection from oxygen-induced cell damage, and generation of deoxyribonucleotide precursors for DNA synthesis. Glutathione reductase together with NADPH, glutathione, and glutaredoxin make up a second hydrogen donor system in E. coli in addition to the thioredoxin system [Holmgren76] (see glutathione redox reactions II and thioredoxin pathway).
Glutathione reductase is a member of the family of flavin-dependent pyridine nucleotide-disulfide oxidoreductases. Other members of this family include thioredoxin reductase, lipoamide dehydrogenase, 2-oxopropyl-CoM reductase (carboxylating), trypanothione reductase, and mercury(II) reductase [Mittl94].
In mutants lacking glutathione reductase activity the ratio of reduced to oxidized glutathione is not significantly changed suggesting that either alternative enzymes exist, or the thioredoxin pathway may also participate [Tuggle85, Ritz01a]. These mutations also cause no growth defect, although the activity of glutathione reductase appears to be essential to maintaining a high glutathione content [Davis82, Kunert90].
The native E. coli enzyme has been purified, characterized, and its redox interconversions studied [Pigiet77, Mata84, Mata85, Mata85a, Arscott89]. The gene was cloned and the recombinant enzyme was also studied [Greer86, Scrutton87, Perham87a]. A number of site-directed mutagenesis studies have investigated the structure and catalytic mechanism of Gor [Scrutton88, Deonarain89, Deonarain90, Scrutton90, Deonarain92, Deonarain92a, Rietveld94, vandenBerg98]. The E. coli enzyme has also been subjected to comparative kinetic analysis with eukaryotic enzymes [Vanoni90, Veine98]. Cell-free synthesis of active E. coli Gor has also been demonstrated [Knapp04].
Crystal structures of the wild-type and mutant Gor enzymes have been determined [Ermler91, Mittl93, Mittl94a, Mittl94]. The enzyme was shown to catalyze the reduction of glutathione disulfide via two half-reactions. In the reductive half-reaction FAD is reduced by NADPH and electrons pass from the reduced flavin to the redox-active disulfide. The oxidative half-reaction involves dithiol-disulfide interchange between the enzyme dithiol and glutathione disulfide [Rietveld94]. More recently, it was shown that E. coli Gor can catalyze the NADPH-dependent reduction of AuCl4- to form gold nanoparticles at the active site that were tightly bound through the catalytic cysteines, and could be removed from the active site by thiol reagents [Scott08].
Locations: membrane, cytosol
|Map Position: [3,644,322 -> 3,645,674]|
Molecular Weight of Polypeptide: 48.772 kD (from nucleotide sequence), 55.0 kD (experimental) [Mata84 ]
Molecular Weight of Multimer: 109.0 kD (experimental) [Mata84]
Unification Links: ASAP:ABE-0011432 , CGSC:665 , EchoBASE:EB0407 , EcoGene:EG10412 , EcoliWiki:b3500 , ModBase:P06715 , OU-Microarray:b3500 , PortEco:gor , PR:PRO_000022829 , Pride:P06715 , Protein Model Portal:P06715 , RefSeq:NP_417957 , RegulonDB:EG10412 , SMR:P06715 , String:511145.b3500 , UniProt:P06715
Relationship Links: InterPro:IN-FAMILY:IPR001327 , InterPro:IN-FAMILY:IPR004099 , InterPro:IN-FAMILY:IPR006322 , InterPro:IN-FAMILY:IPR012999 , InterPro:IN-FAMILY:IPR013027 , InterPro:IN-FAMILY:IPR016156 , InterPro:IN-FAMILY:IPR023753 , PDB:Structure:1GER , PDB:Structure:1GES , PDB:Structure:1GET , PDB:Structure:1GEU , Pfam:IN-FAMILY:PF00070 , Pfam:IN-FAMILY:PF02852 , Pfam:IN-FAMILY:PF07992 , Prints:IN-FAMILY:PR00368 , Prosite:IN-FAMILY:PS00076
|Biological Process:||GO:0006749 - glutathione metabolic process
GO:0045454 - cell redox homeostasis [GOA01a]
GO:0055114 - oxidation-reduction process [UniProtGOA11a, GOA01a]
|Molecular Function:||GO:0004362 - glutathione-disulfide reductase activity
[GOA01, GOA01a, Mata84]
GO:0042803 - protein homodimerization activity [Mata84]
GO:0071949 - FAD binding [Pigiet77]
GO:0016491 - oxidoreductase activity [UniProtGOA11a, GOA01a]
GO:0016668 - oxidoreductase activity, acting on a sulfur group of donors, NAD(P) as acceptor [GOA01a]
GO:0050660 - flavin adenine dinucleotide binding [GOA01a]
GO:0050661 - NADP binding [GOA01a]
|Cellular Component:||GO:0005829 - cytosol
GO:0016020 - membrane [Lasserre06]
GO:0005737 - cytoplasm [UniProtGOA11, UniProtGOA11a]
Enzymatic reaction of: glutathione reductase
Synonyms: GR, GRase, NADPH:oxidized-glutathione oxidoreductase
EC Number: 18.104.22.168
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.
The reaction is physiologically favored in the direction shown.
In Pathways: glutathione redox reactions II
The Km values for NADPH, NADH, and glutathione disulfide at pH 7.5 were 16 μM, 377 μM and 66 μM, respectively. The optimum pH was 7.5 with NADPH and 4.5 with NADH as reductant [Mata84].
pH(opt) (forward direction): 7.5 [Mata84]
|Feature Class||Location||Attached Group||Citations||Comment|
|Nucleotide-Phosphate-Binding-Region||34 -> 41||FAD|
10/20/97 Gene b3500 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10412; confirmed by SwissProt match.
Arscott89: Arscott LD, Drake DM, Williams CH (1989). "Inactivation-reactivation of two-electron reduced Escherichia coli glutathione reductase involving a dimer-monomer equilibrium." Biochemistry 28(8);3591-8. PMID: 2663073
Davis82: Davis NK, Greer S, Jones-Mortimer MC, Perham RN (1982). "Isolation and mapping of glutathione reductase-negative mutants of Escherichia coli K12." J Gen Microbiol 128(7);1631-4. PMID: 6214613
Deonarain89: Deonarain MP, Berry A, Scrutton NS, Perham RN (1989). "Alternative proton donors/acceptors in the catalytic mechanism of the glutathione reductase of Escherichia coli: the role of histidine-439 and tyrosine-99." Biochemistry 28(25);9602-7. PMID: 2558727
Deonarain90: Deonarain MP, Scrutton NS, Berry A, Perham RN (1990). "Directed mutagenesis of the redox-active disulphide bridge in glutathione reductase from Escherichia coli." Proc R Soc Lond B Biol Sci 1990;241(1302);179-86. PMID: 1979442
Deonarain92: Deonarain MP, Scrutton NS, Perham RN (1992). "Engineering surface charge. 1. A method for detecting subunit exchange in Escherichia coli glutathione reductase." Biochemistry 31(5);1491-7. PMID: 1737008
Deonarain92a: Deonarain MP, Scrutton NS, Perham RN (1992). "Engineering surface charge. 2. A method for purifying heterodimers of Escherichia coli glutathione reductase." Biochemistry 31(5);1498-504. PMID: 1737009
Greer86: Greer S, Perham RN (1986). "Glutathione reductase from Escherichia coli: cloning and sequence analysis of the gene and relationship to other flavoprotein disulfide oxidoreductases." Biochemistry 25(9);2736-42. PMID: 3521741
Henderson91: Henderson GB, Murgolo NJ, Kuriyan J, Osapay K, Kominos D, Berry A, Scrutton NS, Hinchliffe NW, Perham RN, Cerami A (1991). "Engineering the substrate specificity of glutathione reductase toward that of trypanothione reduction." Proc Natl Acad Sci U S A 88(19);8769-73. PMID: 1924337
Kunert90: Kunert KJ, Cresswell CF, Schmidt A, Mullineaux PM, Foyer CH (1990). "Variations in the activity of glutathione reductase and the cellular glutathione content in relation to sensitivity to methylviologen in Escherichia coli." Arch Biochem Biophys 1990;282(2);233-8. PMID: 2241146
Lasserre06: Lasserre JP, Beyne E, Pyndiah S, Lapaillerie D, Claverol S, Bonneu M (2006). "A complexomic study of Escherichia coli using two-dimensional blue native/SDS polyacrylamide gel electrophoresis." Electrophoresis 27(16);3306-21. PMID: 16858726
Mata84: Mata AM, Pinto MC, Lopez-Barea J (1984). "Purification by affinity chromatography of glutathione reductase (EC 22.214.171.124) from Escherichia coli and characterization of such enzyme." Z Naturforsch [C] 39(9-10);908-15. PMID: 6393625
Mata85: Mata AM, Pinto MC, Lopez-Barea J (1985). "Redox interconversion of glutathione reductase from Escherichia coli. A study with pure enzyme and cell-free extracts." Mol Cell Biochem 67(1);65-76. PMID: 3894932
Mata85a: Mata AM, Pinto MC, Lopez-Barea J (1985). "Redox interconversion of Escherichia coli glutathione reductase. A study with permeabilized and intact cells." Mol Cell Biochem 68(2);121-30. PMID: 3908906
Mittl93: Mittl PR, Berry A, Scrutton NS, Perham RN, Schulz GE (1993). "Structural differences between wild-type NADP-dependent glutathione reductase from Escherichia coli and a redesigned NAD-dependent mutant." J Mol Biol 231(2);191-5. PMID: 8510142
Mittl94: Mittl PR, Schulz GE (1994). "Structure of glutathione reductase from Escherichia coli at 1.86 A resolution: comparison with the enzyme from human erythrocytes." Protein Sci 3(5);799-809. PMID: 8061609
Rietveld94: Rietveld P, Arscott LD, Berry A, Scrutton NS, Deonarain MP, Perham RN, Williams CH (1994). "Reductive and oxidative half-reactions of glutathione reductase from Escherichia coli." Biochemistry 33(46);13888-95. PMID: 7947797
Scott08: Scott D, Toney M, Muzikar M (2008). "Harnessing the mechanism of glutathione reductase for synthesis of active site bound metallic nanoparticles and electrical connection to electrodes." J Am Chem Soc 130(3);865-74. PMID: 18166048
Scrutton87: Scrutton NS, Berry A, Perham RN (1987). "Purification and characterization of glutathione reductase encoded by a cloned and over-expressed gene in Escherichia coli." Biochem J 245(3);875-80. PMID: 3311037
Scrutton90: Scrutton NS, Berry A, Deonarain MP, Perham RN (1990). "Active site complementation in engineered heterodimers of Escherichia coli glutathione reductase created in vivo." Proc Biol Sci 242(1305);217-24. PMID: 1983037
vandenBerg98: van den Berg PA, van Hoek A, Walentas CD, Perham RN, Visser AJ (1998). "Flavin fluorescence dynamics and photoinduced electron transfer in Escherichia coli glutathione reductase." Biophys J 74(4);2046-58. PMID: 9545063
Vanoni90: Vanoni MA, Wong KK, Ballou DP, Blanchard JS (1990). "Glutathione reductase: comparison of steady-state and rapid reaction primary kinetic isotope effects exhibited by the yeast, spinach, and Escherichia coli enzymes." Biochemistry 29(24);5790-6. PMID: 2200516
Veine98: Veine DM, Arscott LD, Williams CH (1998). "Redox potentials for yeast, Escherichia coli and human glutathione reductase relative to the NAD+/NADH redox couple: enzyme forms active in catalysis." Biochemistry 37(44);15575-82. PMID: 9799522
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