Reaction: pyruvate oxime + O2 = pyruvate + nitrite
Glossary: pyruvate oxime = pyruvic oxime = 2-(hydroxyimino)propanoate
Other name(s): POD (ambiguous)
Systematic name: pyruvate oxime:oxygen oxidoreductase (nitrite-forming)
Comments: This enzyme, first reported from the heterotrophic nitrifier Alcaligenes faecalis, oxidizes pyruvate oxime, which is formed spontaneously from hydroxylamine and pyruvate, to nitrite and pyruvate. Despite its similarity to class II aldolases, the active site contains Fe(II) rather than the common Zn(II). Activity requires that the iron is kept in Fe(II) state, and is enhanced by inclusion of reducing agents in the reaction mixture. The iron at the active site is coordinated by three histidines and three water molecules.
b>Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:
References:
1. Ono, Y., Makino, N., Hoshino, Y., Shoji, K. and Yamanaka, T. An iron dioxygenase from Alcaligenes faecalis catalyzing the oxidation of pyruvic oxime to nitrite. FEMS Microbiol. Lett. 139 (1996) 103-108. [PMID: 8674977]
2. Ono, Y., Enokiya, A., Masuko, D., Shoji, K. and Yamanaka, T. Pyruvic oxime dioxygenase from the heterotrophic nitrifier Alcaligenes faecalis: purification, and molecular and enzymatic properties. Plant Cell Physiol. 40 (1999) 47-52.
3. Tsujino, S., Uematsu, C., Dohra, H. and Fujiwara, T. Pyruvic oxime dioxygenase from heterotrophic nitrifier Alcaligenes faecalis is a nonheme Fe(II)-dependent enzyme homologous to class II aldolase. Sci. Rep. 7 (2017) 39991. [PMID: 28059164]
4. Tsujino, S., Yamada, Y., Senda, M., Nakamura, A., Senda, T. and Fujiwara, T. Structural characterization of pyruvic oxime dioxygenase, a key enzyme in heterotrophic nitrification. J. Bacteriol. 207 (2025) e0034224. [PMID: 39772954]