Function
Uridine 5’-monophosphate synthase (UMPS) is a bifunctional enzyme catalyzes the formation of uridine monophosphate (UMP)[1]. UMPS N-terminal domain is an orotate phosphoribosyltransferase (OPRT) subunit which catalyzes the addition of ribose-phosphate to orotate forming orotidine 5’-monophosphate (OMP). The C-terminal subunit is orotidine 5’-phosphate decarboxylase (OPD) which decarboxylates OMP to form UMP. A potent inhibitor of OPD is BMP – a barbituric acid derivative.
Disease
Defects in UMPS result in the hereditary rare metabolic disease orotic aciduria[2]. UMPS deficiency in Holstein cattle results in an autosomal disorder which causes early embryonic death of offspring[3].
Structural highlights
in its [4] (the surface of chain B doesn't shown). Water molecules shown as red spheres.