1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate A flavoprotein (FAD, FMN). Ferricyanide can act as accetor - 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate cysteine and serine are active site base residues. One-site ping-pong mechanism with fumarate as electron acceptor 390913 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate light - 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate light sensitivity seems to result in a conformational change and a partial loss of enzymatic activity 390911 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate mechanism, pyrimidine biosynthetic pathways 390912 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate ping-pong bi-bi mechanism 656747 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate ping-pong mechanism 390916 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate sulfhydryl groups suggested to be located near the active site, suggested that enzyme produces superoxide free radicals upon reaction with oxygen 390909 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate the active site contains a water filled cavity buried beneath a highly conserved and flexible loop. Orotate is bound by four conserved asparagine side chains. Implications for differences in substrate binding and in the catalytic mechanism between the different enzyme families are given 390915 1.3.98.1 (S)-dihydroorotate + fumarate = orotate + succinate two-site ping-pong mechanism, catalytic base is serine 655517