Oxidoreductases;
Acting on phosphorus or arsenic in donors;
With disulfide as acceptor
BRITE hierarchy

arsenate:glutathione/glutaredoxin oxidoreductase

arsenate + glutathione + glutaredoxin = arsenite + a glutaredoxin-glutathione disulfide + H2O [RN:R05747]

R05747
Reaction

arsenate [CPD:C11215];
glutathione [CPD:C00051];
glutaredoxin [CPD:C07292]

The enzyme is part of a system for detoxifying arsenate. The substrate binds to a catalytic cysteine residue, forming a covalent thiolate---As(V) intermediate. A tertiary intermediate is then formed between the arsenic, the enzyme's cysteine, and a glutathione cysteine. This intermediate is reduced by glutaredoxin, which forms a dithiol with the glutathione, leading to the dissociation of arsenite. Thus reduction of As(V) is mediated by three cysteine residues: one in ArsC, one in glutathione, and one in glutaredoxin. Although the arsenite formed is more toxic than arsenate, it can be extruded from some bacteria by EC 7.3.2.7, arsenite-transporting ATPase; in other organisms, arsenite can be methylated by EC 2.1.1.137, arsenite methyltransferase, in a pathway that produces non-toxic organoarsenical compounds. cf. EC 1.20.4.4, arsenate reductase (thioredoxin).

EC 1.20.4.1 created 2000 as EC 1.97.1.5, transferred 2001 to EC 1.20.4.1, modified 2015, modified 2019, modified 2020