Number of Cysteine Interactions with the Activity in GRX Family

Grx families are small proteins that are present in eukaryotic and prokaryotic organisms, and in a few viruses, most species have several glutaredoxin isoforms. This study primarily aims a comparative analysis on the duplication of amino acids and its effect on protein function and interaction with the active site. The second active-site cysteine or non-catalytic cysteine affects the reactivity of the catalytic cysteine. Most of the proteins can form an intramolecular the disulfide between cysteines of the two active sites, which could play the role of a protective mechanism for the cell. The non-catalytic cysteine is unnecessary for deglutathionylation reaction or a true catalytic intermediate formed during the reduction of particular disulfide substrates or in particular conditions or compartments where glutathione levels are insufficient to support Grx regeneration. However, all these factors can be influenced by differences in the expression pattern and subcellular localization.