Type: | Family | Name: | Glutaredoxin, GrxC |
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, 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.Glutaredoxin has been sequenced in a variety of species. On the basis of extensive sequence similarity, it has been proposed [] that Vaccinia virusprotein O2L is most probably a glutaredoxin. Finally, it must be noted that Bacteriophage T4thioredoxin seems also to be evolutionary related. In position 5 of the pattern T4 thioredoxin has Val instead of Pro.This family of glutaredoxins includes the Escherichia coliprotein GrxC (Grx3) which 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 []. | Short Name: | GRX_bact |