Plant dihydroorotate dehydrogenase differs significantly in substrate specificity and inhibition from the animal enzymes.
The mitochondrial membrane bound dihydroorotate dehydrogenase (DHODH; EC 1.3.99.11) catalyzes the fourth step of pyrimidine biosynthesis. By the present correction of a known cDNA sequence for Arabidopsis thaliana DHODH we revealed the importance of the very C-terminal part for its catalytic activity and the reason why--in contrast to mammalian and insect species--the recombinant plant flavoenzyme was unaccessible to date for in vitro characterization. Structure-activity relationship studies explained that potent inhibitors of animal DHODH do not significantly affect the plant enzyme. These difference could be exploited for a novel approach to herb or pest growth control by limitation of pyrimidine nucleotide pools.
Ullrich
Alexandra
A
Institute for Physiological Chemistry, Philipps-University, Karl-von-Frisch-Strasse 1, D-35033 Marburg, Germany. ullricha@mailer.uni-marburg.de
Knecht
Wolfgang
W
Piskur
Jure
J
Löffler
Monika
M
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary; D000090722:Dihydroorotate Dehydrogenase; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D044925:Oxidoreductases Acting on CH-CH Group Donors; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity
D017931:DNA Primers; D018076:DNA, Complementary; D000090722:Dihydroorotate Dehydrogenase; D011994:Recombinant Proteins; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors