Oxidoreductases;
Acting on the CH-CH group of donors;
With NAD+ or NADP+ as acceptor
BRITE hierarchy

(S)-dihydroorotate:NAD+ oxidoreductase

(S)-dihydroorotate + NAD+ = orotate + NADH + H+ [RN:R01869]

R01869
Reaction

(S)-dihydroorotate [CPD:C00337];
NAD+ [CPD:C00003]

Binds FMN, FAD and a [2Fe-2S] cluster. The enzyme consists of two subunits, an FMN binding catalytic subunit and a FAD and iron-sulfur binding electron transfer subunit [4]. The reaction, which takes place in the cytosol, is the only redox reaction in the de-novo biosynthesis of pyrimidine nucleotides. Other class 1 dihydroorotate dehydrogenases use either fumarate (EC 1.3.98.1) 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.

EC 1.3.1.14 created 1972, modified 2011