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EC
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1.1.99.19
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| Transferred entry: | uracil dehydrogenase. Now EC 1.17.99.4, uracil/thymine dehydrogenase
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| [EC 1.1.99.19 created 1961 as EC 1.2.99.1, transferred 1984 to EC 1.1.99.19, deleted 2006] |
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| EC |
1.17.99.4 |
| Accepted name: |
uracil/thymine dehydrogenase |
| Reaction: |
(1) uracil + H2O + acceptor = barbiturate + reduced acceptor
(2) thymine + H2O + acceptor = 5-methylbarbiturate + reduced acceptor |
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For diagram of pyrimidine catabolism, 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: 9029-00-9 |
| 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. Uracil oxidase and the isolation of barbituric acid from uracil oxidation. J. Biol. Chem. 194 (1952) 785–791. [PMID: 14927672] |
| 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. [DOI] [PMID: 11485332] |
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| [EC 1.17.99.4 created 1961 as EC 1.2.99.1, transferred 1984 to EC 1.1.99.19, transferred 2006 to EC 1.17.99.4] |
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| EC |
3.5.2.1 |
| Accepted name: |
barbiturase |
| Reaction: |
barbiturate + H2O = 3-oxo-3-ureidopropanoate |
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For diagram of pyrimidine catabolism, click here |
| Glossary: |
barbiturate = 6-hydroxyuracil |
| Systematic name: |
barbiturate amidohydrolase (3-oxo-3-ureidopropanoate-forming) |
| Comments: |
Contains zinc and is specific for barbiturate as substrate [3]. Forms part of the oxidative pyrimidine-degrading pathway in some microorganisms, along with EC 1.17.99.4 (uracil/thymine dehydrogenase) and EC 3.5.1.95 (N-malonylurea hydrolase). It was previously thought that the end-products of the reaction were malonate and urea but this has since been disproved [2]. May be involved in the regulation of pyrimidine metabolism, along with EC 2.4.2.9, uracil phosphoribosyltransferase. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9025-16-5 |
| 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. |
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. [DOI] [PMID: 11485332] |
| 3. |
Soong, C.L., Ogawa, J., Sakuradani, E. and Shimizu, S. Barbiturase, a novel zinc-containing amidohydrolase involved in oxidative
pyrimidine metabolism. J. Biol. Chem. 277 (2002) 7051–7058. [DOI] [PMID: 11748240] |
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| [EC 3.5.2.1 created 1961, modified 2006] |
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| EC |
3.5.2.13 |
| Accepted name: |
2,5-dioxopiperazine hydrolase |
| Reaction: |
2,5-dioxopiperazine + H2O = glycylglycine |
| Other name(s): |
cyclo(Gly-Gly) hydrolase; cyclo(glycylglycine) hydrolase |
| Systematic name: |
2,5-dioxopiperazine amidohydrolase |
| Comments: |
Highly specific; does not hydrolyse other dioxopiperazines, glycylglycine, proteins or barbiturates. |
| Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 97599-45-6 |
| References: |
| 1. |
Suzuki, Y. and Uchida, K. Multiple forms of α-glycosidase from pig duodenum. Agric. Biol. Chem. 49 (1985) 1573–1581. |
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| [EC 3.5.2.13 created 1989] |
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