Enzymes
| UniProtKB help_outline | 1,201 proteins |
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- Name help_outline 5,6-dihydrothymine Identifier CHEBI:27468 (CAS: 696-04-8) help_outline Charge 0 Formula C5H8N2O2 InChIKeyhelp_outline NBAKTGXDIBVZOO-UHFFFAOYSA-N SMILEShelp_outline CC1CNC(=O)NC1=O 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADP+ Identifier CHEBI:58349 Charge -3 Formula C21H25N7O17P3 InChIKeyhelp_outline XJLXINKUBYWONI-NNYOXOHSSA-K SMILEShelp_outline NC(=O)c1ccc[n+](c1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,285 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H+ Identifier CHEBI:15378 Charge 1 Formula H InChIKeyhelp_outline GPRLSGONYQIRFK-UHFFFAOYSA-N SMILEShelp_outline [H+] 2D coordinates Mol file for the small molecule Search links Involved in 9,431 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline NADPH Identifier CHEBI:57783 (Beilstein: 10411862) help_outline Charge -4 Formula C21H26N7O17P3 InChIKeyhelp_outline ACFIXJIJDZMPPO-NNYOXOHSSA-J SMILEShelp_outline NC(=O)C1=CN(C=CC1)[C@@H]1O[C@H](COP([O-])(=O)OP([O-])(=O)OC[C@H]2O[C@H]([C@H](OP([O-])([O-])=O)[C@@H]2O)n2cnc3c(N)ncnc23)[C@@H](O)[C@H]1O 2D coordinates Mol file for the small molecule Search links Involved in 1,279 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline thymine Identifier CHEBI:17821 (Beilstein: 607626; CAS: 65-71-4) help_outline Charge 0 Formula C5H6N2O2 InChIKeyhelp_outline RWQNBRDOKXIBIV-UHFFFAOYSA-N SMILEShelp_outline Cc1c[nH]c(=O)[nH]c1=O 2D coordinates Mol file for the small molecule Search links Involved in 11 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:58284 | RHEA:58285 | RHEA:58286 | RHEA:58287 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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Properties and assay of dihydrouracil dehydrogenase of rat liver.
FRITZSON P.
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Purification and properties of dihydrothymine dehydrogenase from rat liver.
Shiotani T., Weber G.
Rat liver dihydrothymine dehydrogenase, the rate-limiting enzyme of thymidine and uridine degradation, was purified to homogeneity as judged by polyacrylamide disc gel electrophoresis, sedimentation velocity, and Ultrogel ACA-34 elution profile. The enzyme has a molecular weight of 220,000 +/-5,00 ... >> More
Rat liver dihydrothymine dehydrogenase, the rate-limiting enzyme of thymidine and uridine degradation, was purified to homogeneity as judged by polyacrylamide disc gel electrophoresis, sedimentation velocity, and Ultrogel ACA-34 elution profile. The enzyme has a molecular weight of 220,000 +/-5,000 as determined by Ultrogel ACA-34 and sedimentation equilibrium The s20,w value of the enzyme was 9.2 S. The isoelectric point was at pH 5.25. The enzyme is composed of two identical subunits of an approximate molecular weight of 110,000 +/-3,000 as determined by sodium dodecyl sulfate disc gel electrophoresis. The enzyme contains 4 mol of FAD and 3 mol of iron per mol of enzyme. Flavin released from the enzyme by boiling was identified as FAD by absorption spectra and thin layer chromatography, indicating that the enzyme is a flavometal protein. During dialysis, the enzyme was stabilized by 2-mercaptoethanol, but neither NADPH nor thymine was effective. The relative rates of reduction of pyrimidine analogues substituted at position 5 were 5-fluorouracil > 5-bromouracil > 5-diazouracil > 5-iodouracil > 5-nitrouracil, with 5-fluorouracil and 5-diazouracil 70% faster than thymine. Uracil was reduced 25% faster than thymine. The pH optimum for the forward and reverse reactions was 7.4. In the presence of NADPH, the apparent Km was 2.6 microM for thymine and 1.8 microM for uracil. Apparent Km for NADPH was 15 microM with thymine as substrate and 11 microM with uracil. In the reverse reaction, apparent Km values were 43 microM for dihydrothymine and 193 microM for dihydrouracil; apparent Km for NADP+ was 3.8 microM with dihydrothymine as substrate and 2.9 microM with dihydrouracil. << Less
J Biol Chem 256:219-224(1981) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.