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Protein Domain : IPR011900

Description  Glutaredoxins [ , , ], also known as thioltransferases (disulphide reductases), are small proteins of approximately one hundred amino-acid residues which utilise glutathione and NADPH as cofactors. Oxidized glutathione is regenerated by glutathione reductase. Together these components compose the glutathione system [].Glutaredoxin functions as an electron carrier in the glutathione-dependent synthesis of deoxyribonucleotides by the enzyme ribonucleotide reductase. Like thioredoxin (TRX), which functions in a similar way, glutaredoxin possesses an active centre disulphide bond [ ]. It exists in either a reduced or an oxidized form where the two cysteine residues are linked in an intramolecular disulphide bond. It contains a redox active CXXC motif in a TRX fold and uses a similar dithiol mechanism employed by TRXs for intramolecular disulfide bond reduction of protein substrates. Unlike TRX, GRX has preference for mixed GSH disulfide substrates, in which it uses a monothiol mechanism where only the N-terminal cysteine is required. The flow of reducing equivalents in the GRX system goes from NADPH ->GSH reductase ->GSH ->GRX ->protein substrates [ , , , ]. By altering the redox state of target proteins, GRX is involved in many cellular functions including DNA synthesis, signal transduction and the defense against oxidative stress.Glutaredoxin has been sequenced in a variety of species. On the basis of extensive sequence similarity, it has been proposed [ ] that Vaccinia virus protein O2L is most probably a glutaredoxin. Finally, it must be noted that Bacteriophage T4 thioredoxin seems also to be evolutionary related. In position 5 of the pattern T4 thioredoxin has Val instead of Pro.This subfamily of bacterial glutaredoxins (GRX) includes Escherichia coli Grx1 (GrxC1) and Grx3 (GrxC). GrxC appears to have a secondary role in reducing ribonucleotide reductase (in the absence of GrxA) possibly indicating a role in the reduction of other protein disulphides [ , ]. Name  Glutaredoxin, GrxC
Short Name  GRX_bact Type  Family
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12 Publications

Genomics

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