Orotidine 5'-monophosphate (OMP), also known as orotidylic acid, is a
pyrimidine
Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The othe ...
nucleotide
Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecu ...
which is the last intermediate in the biosynthesis of
uridine monophosphate
Uridine monophosphate (UMP), also known as 5′-uridylic acid (conjugate base uridylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside uridine. UMP consists of the phosphate group, th ...
. OMP is formed from
orotate
Orotic acid is a pyrimidinedione and a carboxylic acid. Historically, it was believed to be part of the vitamin B complex and was called vitamin B13, but it is now known that it is not a vitamin.
The compound is synthesized in the body via a m ...
and
phosphoribosyl pyrophosphate by the enzyme
orotate phosphoribosyltransferase
In humans, the enzyme
UMP synthase converts OMP into
uridine 5'- monophosphate. If UMP synthase is defective,
orotic aciduria
Orotic aciduria (AKA hereditary orotic aciduria) is a disease caused by an enzyme deficiency resulting in a decreased ability to synthesize pyrimidines. It was the first described enzyme deficiency of the ''de novo'' pyrimidine synthesis pathway.
...
can result.
Nucleotides
Pyrimidinediones
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