Chemical models and their mechanistic implications for the transformation of 6-cyanouridine 5'-monophosphate catalyzed by orotidine 5'-monophosphate decarboxylase.

The reactions of 6-cyano-1,3-dimethyluracil have been studied as chemical models to illustrate the mechanism for the transformation of 6-cyanouridine 5'-monophosphate (6-CN-UMP) to barbiturate ribonucleoside 5'-monophosphate (BMP) catalyzed by orotidine 5'-monophosphate decarboxylase (ODCase). The results suggest that the Asp residue in the ODCase active site plays the role of a general base in the transformation.