3GDM LYASE, OROTIDINE 5'-MONOPHOSPHATE DECARBOXYLASE, SACCHAROMYCES CEREVISIAE, K93R MUTANT, DECARBOXYLASE, PHOSPHOPROTEIN, PYRIMIDINE BIOSYNTHESIS, UBL CONJUGATION CRYSTAL STRUCTURE OF THE K93R MUTANT OF THE OROTIDINE 5'- MONOPHOSPHATE DECARBOXYLASE FROM SACCHAROMYCES CEREVISIAE