Phage T7 DNA polymerase contains Escherichia coli thioredoxin as a subunit and is a 1:1 complex with T7 gene 5 protein. The enzyme showed high thioredoxin activity in assays at 37 degrees C using reduction of insulin disulfides with NADPH and thioredoxin reductase, leading Randahl (Randahl, H. (1982) FEBS Lett. 150, 109-113) to propose that the thioredoxin dithiol active site is exposed in T7 D...

The Saccharomyces cerevisiae Yap1p transcription factor is required for the H2O2-dependent activation of many antioxidant genes including the TRX2 gene encoding thioredoxin 2. To identify factors that regulate Yap1p activity, we carried out a genetic screen for mutants that show elevated expression of a TRX2-HIS3 fusion in the absence of H2O2. Two independent mutants isolated in this screen car...

The reductive formation of deoxycytidine diphosphate from cytidine diphosphate with crude extracts of Escherichia coli B required the presence of reduced triphosphopyridine nucleotide (1). On purification of the GDP-reductase system, an enzyme fraction (Fraction B) was obtained, which was no longer active with TPNH but, instead, showed an absolute requirement for reduced lipoate (2, 3). Several...

In this report we describe the cloning, organization, and promoter analysis of the Staphylococcus aureus thioredoxin (trxA) and thioredoxin reductase (trxB) genes and their transcription in response to changes in oxygen concentration and to oxidative stress compounds. Northern analysis showed that the S. aureus trxA and trxB genes were transcribed equally well in aerobic and anaerobic condition...

Reporter gene transactivation by human p53 is compromised in S. cerevisiae lacking the TRR1 gene encoding thioredoxin reductase. The basis for p53 inhibition was investigated by measuring the redox state of thioredoxin and glutathione in wild-type and Deltatrr1 yeast. The Deltatrr1 mutation affected the redox state of both molecules. About 34% of thioredoxin was in the disulfide form in wild-ty...

Alzheimer’s disease is a debilitating neurodegenerative disease characterized by the formation of insoluble amyloid plaques in the brain. Escherichia coli curli, encoded by the csg gene, is the prokaryotic equivalent of amyloid protein. To study the effect of a reducing protein on the solubility of curli, attempts were made to fuse curli to thioredoxin and flavin reductase. Both proteins are be...

Thioredoxins are a class of low molecular weight redox proteins that undergo reversible reduction-oxidation of two active-site cysteine residues with reduction catalyzed by the NADPH-dependent flavoenzyme thioredoxin reductase. Human thioredoxin has been shown to be identical to a previously reported leukemic cell growth factor. We now report that recombinant human thioredoxin added to minimal ...

Energetic nutrients are oxidized to sustain high intracellular NADPH/NADP+ ratios. NADPH-dependent reduction of thioredoxin-1 (Trx1) disulfide and glutathione disulfide by thioredoxin reductase-1 (TrxR1) and glutathione reductase (Gsr), respectively, fuels antioxidant systems and deoxyribonucleotide synthesis. Mouse livers lacking both TrxR1 and Gsr sustain these essential activities using an N...

Platyhelminth parasites are a major health problem in developing countries. In contrast to their mammalian hosts, platyhelminth thiol-disulfide redox homeostasis relies on linked thioredoxin-glutathione systems, which are fully dependent on thioredoxin-glutathione reductase (TGR), a promising drug target. TGR is a homodimeric enzyme comprising a glutaredoxin domain and thioredoxin reductase (TR...

The thioredoxin system exists ubiquitously and participates in essential antioxidant and redox-regulation processes via a pair of conserved cysteine residues. In Mycobacterium tuberculosis, which lacks a genuine glutathione system, the thioredoxin system provides reducing equivalents inside the cell. The three-dimensional structure of thioredoxin reductase from M. tuberculosis has been determin...