Dihydroorotate is synthesized to orotic acid by the enzyme dihydroorate dehydrogenase, where it later combines with phosphoribosyl pyrophosphate (PRPP) to form orotidine-5'-monophosphate (OMP).
Cyclic guanosine monophosphate | Cyclic adenosine monophosphate | Uridine monophosphate synthetase | Orotidine 5'-monophosphate | orotidine-5'-monophosphate | cyclic guanosine monophosphate |
Uridine phosphorylase adds ribose-1-phosphate to the free base uracil, forming uridine monophosphate.
This bifunctional enzyme is named UMP synthase and it also catalyzes the preceding reaction in pyrimidine nucleotide biosynthesis, the transfer of ribose 5-phosphate from 5-phosphoribosyl-1-pyrophosphate to orotate to form OMP.
Ribavirin 5'-monophosphate inhibits cellular inosine monophosphate dehydrogenase, thereby depleting intracellular pools of GTP.