Reaction: (1) uracil + H2O + acceptor = barbiturate + reduced acceptor
(2) thymine + H2O + acceptor = 5-methylbarbiturate + reduced acceptor
For diagram, click here
Other name(s): uracil oxidase; uracil-thymine oxidase; uracil dehydrogenase
Systematic name: uracil:acceptor oxidoreductase
Comments: Forms part of the oxidative pyrimidine-degrading pathway in some microorganisms, along with EC 3.5.2.1 (barbiturase) and EC 3.5.1.95 (N-malonylurea hydrolase). Mammals, plants and other microorganisms utilize the reductive pathway, comprising EC 1.3.1.1 [dihydrouracil dehydrogenase (NAD+)] or EC 1.3.1.2 [dihydropyrimidine dehydrogenase (NADP+)], EC 3.5.2.2 (dihydropyrimidinase) and EC 3.5.1.6 (β-ureidopropionase), with the ultimate degradation products being an L-amino acid, NH3 and CO2 [5].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Hayaishi, O. and Kornberg, A. Metabolism of cytosine, thymine, uracil, and barbituric acid by bacterial enzymes. J. Biol. Chem. 197 (1952) 717-723. [PMID: 12981104]
2. Wang, T.P. and Lampen, J.O. Metabolism of pyrimidines by a soil bacterium. J. Biol. Chem. 194 (1952) 775-783. [PMID: 14927671]
3. Wang, T.P. and Lampen, J.O. Metabolism of pyrimidines by a soil bacterium. J. Biol. Chem. 194 (1952) 775-783. [PMID: 14927671]
4. Lara, F.J.S. On the decomposition of pyrimidines by bacteria. II. Studies with cell-free enzyme preparations. J. Bacteriol. 64 (1952) 279-285. [PMID: 14955523]
5. Soong, C.L., Ogawa, J. and Shimizu, S. Novel amidohydrolytic reactions in oxidative pyrimidine metabolism: analysis of the barbiturase reaction and discovery of a novel enzyme, ureidomalonase. Biochem. Biophys. Res. Commun. 286 (2001) 222-226. [PMID: 11485332]