| 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 3.6.3.16, arsenite-transporting ATPase; in other organisms, arsenite can be methylated by EC 2.1.1.137, arsenite methyltransferase, in a pathway to non-toxic organoarsenical compounds. |
| References: |
| 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. |
| 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] |
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