Glutaredoxin-2(GrxB) is amember of the glutaredoxin family. Glutaredoxins are small redox enzymes of approximately 100 amino-acid residues which use glutathione as a cofactor. Glutaredoxins are oxidized by substrates, and reduced non-enzymatically by glutathione. GrxB is involved in reducing some disulfides in a coupled system with glutathione reductase. GrxB doesn’t act as hydrogen donor for ribonucleotide reductase.