Binds FMN. 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.
History
EC 1.3.98.1 created 1961 as EC 1.3.3.1, transferred 2011 to EC 1.3.98.1
Rowland P, Bjornberg O, Nielsen FS, Jensen KF, Larsen S
Title
The crystal structure of Lactococcus lactis dihydroorotate dehydrogenase A complexed with the enzyme reaction product throws light on its enzymatic function.
Dihydroorotate dehydrogenase from Saccharomyces cerevisiae: spectroscopic investigations with the recombinant enzyme throw light on catalytic properties and metabolism of fumarate analogues.
Inaoka DK, Sakamoto K, Shimizu H, Shiba T, Kurisu G, Nara T, Aoki T, Kita K, Harada S
Title
Structures of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with substrates and products: atomic resolution insights into mechanisms of dihydroorotate oxidation and fumarate reduction.
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
EC 1.3.5.2 created 1983 as EC 1.3.99.11, transferred 2009 to EC 1.3.5.2, modified 2011
The activity of Escherichia coli dihydroorotate dehydrogenase is dependent on a conserved loop identified by sequence homology, mutagenesis, and limited proteolysis.