Accepted name: 5-pyridoxate monooxygenase
Reaction: 3-hydroxy-4-hydroxymethyl-2-methylpyridine-5-carboxylate + NADPH + H+ + O2 = 2-(acetamidomethylene)-3-(hydroxymethyl)succinate + NADP+
Glossary: 3-hydroxy-4-hydroxymethyl-2-methylpyridine-5-carboxylate = 5-pyridoxate
Other name(s): 5-pyridoxate,NADPH:oxygen oxidoreductase (decyclizing); 5-pyridoxate oxidase (misleading); 5-pyridoxate dioxygenase (incorrect)
Systematic name: 5-pyridoxate,NADPH:oxygen oxidoreductase (ring-opening)
Comments: Contains FAD. The enzyme, characterized from the bacterium Arthrobacter sp. Cr-7, participates in the degradation of pyridoxine (vitamin B6). Although the enzyme was initially thought to be a dioxygenase, oxygen-tracer experiments have suggested that it is a monooxygenase, incorporating only one oxygen atom from molecular oxygen into the product. The second oxygen atom originates from a water molecule, which is regenerated during the reaction and thus does not show up in the reaction equation.
1.  Sparrow, L.G., Ho, P.P.K., Sundaram, T.K., Zach, D., Nyns, E.J. and Snell, E.E. The bacterial oxidation of vitamin B6. VII. Purification, properties, and mechanism of action of an oxygenase which cleaves the 3-hydroxypyridine ring. J. Biol. Chem. 244 (1969) 2590–2600. [PMID: 4306031]
2.  Nelson, M.J. and Snell, E.E. Enzymes of vitamin B6 degradation. Purification and properties of 5-pyridoxic-acid oxygenase from Arthrobacter sp. J. Biol. Chem 261 (1986) 15115–15120. [PMID: 3771566]
3.  Chaiyen, P. Flavoenzymes catalyzing oxidative aromatic ring-cleavage reactions. Arch. Biochem. Biophys. 493 (2010) 62–70. [PMID: 19728986]
[EC created 2018 (EC created 1972, incorporated 2018)]

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