Reaction: arsenate + glutaredoxin = arsenite + glutaredoxin disulfide + H2O
For diagram of reaction click here.
Systematic name: glutharedoxin:arsenate oxidoreductase
Comments: A molybdoenzyme. The glutaredoxins catalyse glutathione-disulfide oxidoreductions and have a redox-active disulfide/dithiol in the active site (-Cys-Pro-Tyr-Cys-) that forms a disulfide bond in the oxidized form [2, 10]. Glutaredoxins have a binding site for glutathione, which is required to reduce them to the dithiol form [3, 6]. Thioredoxins reduced by NADPH and thioredoxin reductase can act as alternative substrates. The enzyme [1, 4, 7, 9] is part of a system for detoxifying arsenate. Although the arsenite formed is more toxic than arsenate, it can be extruded from some bacteria by EC 220.127.116.11, arsenite-transporting ATPase; in other organisms, arsenite can be methylated by EC 18.104.22.168, arsenite methyltransferase, in a pathway to non-toxic organoarsenical compounds.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, UM-BBD, CAS registry number: 146907-46-2
1. Gladysheva, T., Liu, J.Y. and Rosen, B.P. His-8 lowers the pKa of the essential Cys-12 residue of the ArsC arsenate reductase of plasmid R773. J. Biol. Chem. 271 (1996) 33256-33260. [PMID: 8969183]
2. Gladysheva, T.B., Oden, K.L. and Rosen, B.P. Properties of the arsenate reductase of plasmid R773. Biochemistry 33 (1994) 7288-7293. [PMID: 8003492]
3. Holmgren, A. and Aslund, F. Glutaredoxin. Methods Enzymol. 252 (1995) 283-292. [PMID: 7476363]
4. Ji, G.Y., Garber, E.A.E., Armes, L.G., Chen, C.M., Fuchs, J.A. and Silver, S. Arsenate reductase of Staphylococcus aureus plasmid PI258. Biochemistry 33 (1994) 7294-7299. [PMID: 8003493 ]
5. Krafft, T. and Macy, J.M. Purification and characterization of the respiratory arsenate reductase of Chrysiogenes arsenatis. Eur. J. Biochem. 255 (1998) 647-653. [PMID: 9738904]
6. Martin, J.L. Thioredoxin - a fold for all reasons. Structure 3 (1995) 245-250. [PMID: 7788290]
7. Messens, J., Hayburn, G., Desmyter, A., Laus, G. and Wyns, L. The essential catalytic redox couple in arsenate reductase from Staphylococcus aureus. Biochemistry 38 (1999) 16857-16865. [PMID: 10606519]
8. Radabaugh, T.R. and Aposhian, H.V. Enzymatic reduction of arsenic compounds in mammalian systems: reduction of arsenate to arsenite by human liver arsenate reductase. Chem. Res. Toxicol. 13 (2000) 26-30. [PMID: 10649963]
9. Sato, T. and Kobayashi, Y. The ars operon in the skin element of Bacillus subtilis confers resistance to arsenate and arsenite. J. Bacteriol. 180 (1998) 1655-1661. [PMID: 9537360]
10. Shi, J., Vlamis-Gardikas, V., Aslund, F., Holmgren, A. and Rosen, B.P. Reactivity of glutaredoxins 1, 2, and 3 from Escherichia coli shows that glutaredoxin 2 is the primary hydrogen donor to ArsC-catalyzed arsenate reduction. J. Biol. Chem. 274 (1999) 36039-36042. [PMID: 10593884]