Orotate phosphoribosyltransferase (OPRTase) or Orotic acid phosphoribosyltransferase is an enzyme involved in pyrimidine biosynthesis. It catalyzes the formation of orotidine 5'-monophosphate (OMP) from orotate and phosphoribosyl pyrophosphate. In yeast and bacteria, orotate phosphoribosyltransferase is an independent enzyme with a unique gene coding for the protein, whereas in mammals and other multicellular organisms, the catalytic function is carried out by a domain of the bifunctional enzyme UMP synthase.
OPRTase, Native (Brewer's bottom Yeast)
Brewer's bottom yeast
This is the preferred enzyme for assaying orotidine 5′-monophosphate and for the production of OMP analogs from the corresponding orotic acid.
Lyophilized powder containing approx. 50% buffer salts
Enzyme Commission Number
~25 units/mg protein (modified Warburg-Christian)
One unit will convert 1.0 μmole of orotidine 5'-monophosphate to orotic acid in one hr at pH 8.0 at 30°C.
orotidylic acid phosphorylase; orotidine-5'-phosphate pyrophosphorylase; OPRTase; orotate phosphoribosyl pyrophosphate transferase; orotic acid phosphoribosyltransferase; orotidine 5'-monophosphate pyrophosphorylase; orotidine monophosphate pyrophosphorylase; orotidine phosphoribosyltransferase; orotidylate phosphoribosyltransferase; orotidylate pyrophosphorylase; orotidylic acid pyrophosphorylase; orotidylic phosphorylase; orotidylic pyrophosphorylase; EC 18.104.22.168; 9030-25-5