EC Explorer
[browse EC tree] - [search]
EC 1.3.5.2 Details
show Brenda entryEC number
1.3.5.2
Accepted name
dihydroorotate dehydrogenase (quinone)
Reaction
(S)-dihydroorotate + a quinone = orotate + a quinol
Other name(s)
dihydroorotate:ubiquinone oxidoreductase,
(S)-dihydroorotate:(acceptor) oxidoreductase,
(S)-dihydroorotate:acceptor oxidoreductase,
DHOdehase (ambiguous),
DHOD (ambiguous),
DHODase (ambiguous),
DHODH
Systematic name
(S)-dihydroorotate:quinone oxidoreductase
CAS registry number
59088-23-2
Comment
This Class 2 dihydroorotate dehydrogenase enzyme contains FMN [4]. 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 [2,5,6]. The reaction is the only redox reaction in the de-novo biosynthesis of pyrimidine nucleotides [2,4]. 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 [2]. 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 [2]. 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.
History
created 1983 as EC 1.3.99.11, transferred 2009 to EC 1.3.5.2, modified 2011
back to topEC Tree
1 Oxidoreductases
1.1 Acting on the CH-OH group of donors
1.3.1.23 created 1972, deleted 2005 1.3.1.50 created 1992, deleted 1999 1.3.1.55 created 1999, deleted 2004
