Disease relevance of gor

• Seven independently isolated glutathione reductase-deficient (gor) Escherichia coli mutants were found to have an in vivo glutathione redox state that did not significantly differ from that of the parental strain, 98 to 99% reduced [1].
• Interestingly, its expression and enzyme characteristics were different from GR homologue of filarial parasite O. volvulus [2].

High impact information on gor

• Moreover, Grx1 could catalyze disulfide formation in the oxidizing cytosol of combined null mutants for glutathione reductase and thioredoxin 1. grxB(-) cells were more sensitive to hydrogen peroxide and other oxidants and showed increased carbonylation of intracellular proteins, particularly in the stationary phase [3].
• Human thioredoxin reductase is a pyridine nucleotide-disulfide oxidoreductase closely related to glutathione reductase but differing from the latter in having a Cys-SeCys (selenocysteine) sequence as an additional redox center [4].
• These results identify His509 as active site base, but imply that its function can be substituted, although inefficiently, by an alternative proton donor, similar to glutathione reductase [5].
• A scheme is described for the large scale purification of thioredoxin, thioredoxin reductase, and glutathione reductase [6].
• Thioredoxin reductase contains FAD and NADPH binding domains that are structurally similar to the corresponding domains of the related enzyme glutathione reductase [7].

Chemical compound and disease context of gor

• It was found that in addition to being ampicillin sensitive this mutant was hypersensitive to arsenate, which may be connected with the fact that the gor gene maps between 77 and 78 min on the E. coli genome, close to the pit locus encoding the major arsenate transport system of E. coli [8].
• Structural differences between wild-type NADP-dependent glutathione reductase from Escherichia coli and a redesigned NAD-dependent mutant [9].

Biological context of gor

• Restriction mapping of this plasmid showed that the insert DNA is approximately 10 kilobase pairs in length, and a fragment of the gor gene was identified that allowed the gor gene to be accurately mapped on pGR by a combination of restriction analysis and Southern blotting [8].
• The DNA sequence of the gor gene was determined and found to encode a protein of 450 amino acid residues [8].
• To study the function of glutathione reductase and glutathione in Escherichia coli the coding sequence of the bacterial glutathione reductase gene (gor gene) was cloned into the vector pBR322, and the gor gene was expressed under the control of the promoter of the tetracycline-resistance gene (tet gene) in different Escherichia coli strains [10].
• The natural specificity of Escherichia coli glutathione reductase for NADP has previously been converted into a marked preference for NAD by introducing seven point mutations into the beta alpha beta-fold of the NADP-binding domain of the protein based on the known structure of the human enzyme [9].
• Slight down-regulation in the expression of Tigriopus GR at the initial stage was observed upon exposure to hydrogen peroxide [2].

Anatomical context of gor

• Structure of glutathione reductase from Escherichia coli at 1.86 A resolution: comparison with the enzyme from human erythrocytes [11].

Associations of gor with chemical compounds

• A plasmid, pGR, was isolated that encodes both an arsenate-resistance element and glutathione reductase [8].
• Cells of the gor-mutant strain SG5 containing the vector pBR322 (SG5:pBR322) had no detectable glutathione reductase activity and a significantly lower total glutathione (GSH + GSSG) content relative to control cells of the strain JM101 (JM101: pBR322) [10].
• Elevated levels of both glutathione reductase activity and the total glutathione content (GSH + GSSG) were found when the gor gene was expressed in cells of the gor-mutant strain SG5 (SG5:pJIK1) [10].
• Although this position is at a distance of 10 A from the bound 2'-phosphate group of NADP in glutathione reductase, the A179G mutation was found to be synergistic and beneficial [9].
• The simplest possibility is that the NADPH domain rotates between the conformation observed here and an orientation similar to that seen in glutathione reductase [7].

Regulatory relationships of gor

• In sodA mutant cells lacking manganese superoxide dismutase activity but expressing the cloned gor gene (QC772:pJIK1) increased cellular glutathione reductase activity did not provide protection against methylviologen [10].

Other interactions of gor

• The gor gene encoding glutathione reductase lies downstream of dnaA [12].
• The growth of Escherichia coli mutants deficient in glutathione synthesis (gshA) and in glutathione reductase (gor) was suppressed in medium of elevated osmolarity [13].

Analytical, diagnostic and therapeutic context of gor

• To analyze the gene expression of Tigriopus GR against different environmental stresses (hydrogen peroxide, salinity, and heavy metals), we performed real-time reverse transcriptase-polymerase chain reaction (real-time RT-PCR) [2].

References