Orotidine-5'-monophosphate (OMP) is a pyrimidine nucleotide that serves as a precursor in the biosynthesis of uridine monophosphate (UMP), an essential component for RNA synthesis. It is formed from orotate and phosphoribosyl pyrophosphate (PRPP) and is subsequently decarboxylated to UMP by the enzyme orotidine-5'-monophosphate decarboxylase.