orotate phosphoribosyltransferase

or·o·tate phos·pho·ri·bo·syl·trans·fer·ase

a phosphoribosyltransferase synthesizing orotidylate and pyrophosphate from orotate and 5-phospho-α-d-ribosyl-1-pyrophosphate; this enzyme is a part of pyrimidine biosynthesis; a deficiency of this enzyme is associated with orotic aciduria type I. Compare: uridylic acid synthase. Synonym(s): OMP pyrophosphorylase, orotidylic acid phosphorylase, orotidylic acid pyrophosphorylase