Reaction: arsenate + thioredoxin = arsenite + thioredoxin disulfide + H2O
For diagram of reaction click here
Other name(s): ArsC (ambiguous)
Systematic name: arsenate:thioredoxin oxidoreductase
Comments: The enzyme, characterized in bacteria of the Firmicutes phylum, is specific for thioredoxin [1]. It has no activity with glutaredoxin [cf. EC 1.20.4.1, arsenate reductase (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. The enzyme also has the activity of EC 3.1.3.48, protein-tyrosine-phosphatase [3].
Links to other databases: BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. Ji, G., Garber, E.A., 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]
2. 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]
3. Zegers, I., Martins, J.C., Willem, R., Wyns, L. and Messens, J. Arsenate reductase from S. aureus plasmid pI258 is a phosphatase drafted for redox duty. Nat. Struct. Biol. 8 (2001) 843-847. [PMID: 11573087]
4. Messens, J., Martins, J.C., Van Belle, K., Brosens, E., Desmyter, A., De Gieter, M., Wieruszeski, J.M., Willem, R., Wyns, L. and Zegers, I. All intermediates of the arsenate reductase mechanism, including an intramolecular dynamic disulfide cascade. Proc. Natl. Acad. Sci. USA 99 (2002) 8506-8511. [PMID: 12072565]