InterPro domain: IPR001754

Orotidine 5'-phosphate decarboxylase (OMPdecase) [ 1 , 2 ] catalyses the last step in the de novo biosynthesis of pyrimidines, the decarboxylation of OMP into UMP. In higher eukaryotes OMPdecase is part, with orotate phosphoribosyltransferase, of a bifunctional enzyme, while the prokaryotic and fungal OMPdecases are monofunctional protein.

Some parts of the sequence of OMPdecase are well conserved across species. The best conserved region is located in the N-terminal half of OMPdecases and is centred around a lysine residue which is essential for the catalytic function of the enzyme.

This entry also includes enzymes such as 3-hexulose-6-phosphate synthase 4.1.2.43 and 3-keto-L-gulonate-6-phosphate decarboxylase 4.1.1.85 .

1. Sequence analysis of the DdPYR5-6 gene coding for UMP synthase in Dictyostelium discoideum and comparison with orotate phosphoribosyl transferases and OMP decarboxylases. Mol. Gen. Genet. 211, 441-5
2. The orotidine-5'-monophosphate decarboxylase gene of Myxococcus xanthus. Comparison to the OMP decarboxylase gene family. J. Biol. Chem. 267, 819-24