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CATH Superfamily 3.30.70.20

The name of this superfamily has been modified since the most recent official CATH+ release (v4_2_0). At the point of the last release, this superfamily was: waiting to be named.

Functional Families

Overview of the Structural Clusters (SC) and Functional Families within this CATH Superfamily. Clusters with a representative structure are represented by a filled circle.
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FunFam 39799: Dihydropyrimidine dehydrogenase subunit B

There are 4 EC terms in this cluster

Please note: EC annotations are assigned to the full protein sequence rather than individual protein domains. Since a given protein can contain multiple domains, it is possible that some of the annotations below come from additional domains that occur in the same protein, but have been classified elsewhere in CATH.

Note: The search results have been sorted with the annotations that are found most frequently at the top of the list. The results can be filtered by typing text into the search box at the top of the table.

EC Term Annotations Evidence
Dihydrouracil dehydrogenase (NAD(+)). [EC: 1.3.1.1]
(1) 5,6-dihydrouracil + NAD(+) = uracil + NADH. (2) 5,6-dihydrothymine + NAD(+) = thymine + NADH.
  • The enzyme was originally discovered in the uracil-fermenting bacterium, Clostridium uracilicum, which utilizes uracil and thymine as nitrogen and carbon sources for growth.
  • Since then the enzyme was found in additional organisms including Alcaligenes eutrophus, Pseudomonas strains and Escherichia coli.
 674 A0A010SRG7 A0A010SRG7 A0A017IEW4 A0A017IEW4 A0A023CAS4 A0A023CAS4 A0A024KWP4 A0A024KWP4 A0A024L1R3 A0A024L1R3
(664 more...)
Dihydropyrimidine dehydrogenase (NADP(+)). [EC: 1.3.1.2]
5,6-dihydrouracil + NADP(+) = uracil + NADPH.
  • Also acts on dihydrothymine.
 276 A0A023YZL3 A0A023YZL3 A0A024L1R3 A0A024L1R3 A0A025CFH6 A0A025CFH6 A0A026ULG9 A0A026ULG9 A0A027U5J6 A0A027U5J6
(266 more...)
Dihydroorotate dehydrogenase (quinone). [EC: 1.3.5.2]
(S)-dihydroorotate + a quinone = orotate + a quinol.
  • This Class 2 dihydroorotate dehydrogenase enzyme contains FMN.
  • The enzyme is found in eukaryotes in the mitochondrial membrane, in cyanobacteria, and in some Gram-negative and Gram-positive bacteria associated with the cytoplasmic membrane.
  • The reaction is the only redox reaction in the de-novo biosynthesis of pyrimidine nucleotides.
  • The best quinone electron acceptors for the enzyme from bovine liver are ubiquinone-6 and ubiquinone-7, although simple quinones, such as benzoquinone, can also act as acceptor at lower rates.
  • Methyl-, ethyl-, tert-butyl and benzyl-(S)-dihydroorotates are also substrates, but methyl esters of (S)-1-methyl and (S)-3-methyl and (S)-1,3-dimethyldihydroorotates are not.
  • Class 1 dihydroorotate dehydrogenases use either fumarate (EC 1.3.98.1), NAD(+) (EC 1.3.1.14) or NADP(+) (EC 1.3.1.15) as electron acceptor.
  • Formerly EC 1.3.99.11.
 24 A0A085IBQ9 A0A085IBQ9 A0A0R3NZ50 A0A0R3NZ50 A0A0R3P3X8 A0A0R3P3X8 A0A1B7K2F4 A0A1B7K2F4 B3MZM3 B3MZM3
(14 more...)
Dihydroorotate oxidase (fumarate). [EC: 1.3.98.1]
(S)-dihydroorotate + fumarate = orotate + succinate.
  • The reaction, which takes place in the cytosol, is the only redox reaction in the de novo biosynthesis of pyrimidine nucleotides.
  • Molecular oxygen can replace fumarate in vitro.
  • Other class 1 dihydroorotate dehydrogenases use either NAD(+) (EC 1.3.1.14) or NADP(+) (EC 1.3.1.15) as electron acceptor.
  • The membrane bound class 2 dihydroorotate dehydrogenase (EC 1.3.5.2) uses quinone as electron acceptor.
  • Formerly EC 1.3.3.1.
 20 A0A083UUI4 A0A083UUI4 A0A0D5Y2D2 A0A0D5Y2D2 A0A0F4XM23 A0A0F4XM23 A0A173JLS2 A0A173JLS2 A0A1B4WXM3 A0A1B4WXM3
(10 more...)