2.4.2.10	evolution	fusion of the last two enzymes in the pyrimidine biosynthetic pathway in the inversed order by having a C-terminal orotate phosphoribosyltransferase (OPRT) and an N-terminal orotidine 5'-monophosphate decarboxylase (OMPDC), as OMPDC-OPRT, are described in many organisms. During evolution a gene fusion (i.e., the new gene coding for hybrid protein) is the immediate form between a stand-alone gene of a monofunctional enzyme and a gene fission of multienzyme complex (i.e., single gene from multiple smaller coding segments) responsible for protein-protein interaction, in response to different allosteric controls	748831	
2.4.2.10	malfunction	decreased activity of OPRT plays an important role in the acquired resistance of gastric cancer cells towards 5-fluorouracil. OPRT-knockout MKN-45 parent cells using small interfering RNA demonstrate 15.8fold increased resistance to 5-fluorouracil compared to the control cell	706023	
2.4.2.10	physiological function	the enzyme is required for mycelial growth, appressorial turgor pressure and penetration into plant tissues, invasive hyphal growth, and pathogenicity	-, 735519