CDNA CLONING OF BOVINE LIVER DIHYDROPYRIMIDINE DEHYDROGENASE

Dihydropyrimidine dehydrogenase (DPD), the initial and rate-limiting e nzyme in pyrimidine catabolism, has recently been purified to homogene ity from several species. In the present study the molecular cloning o f DPD with isolation of a cDNA coding for bovine liver DPD is reported using polymerase chain reaction (PCR) methodology. Known amino acid s equence from purified bovine DPD was used to initially design mixed ol igonucleotide primers for amplification of a cDNA fragment (65 base pa irs). Specific primers were subsequently designed and utilized in the amplification of the full-length cDNA (4422 base pairs). Sequence anal ysis demonstrated a 74 nucleotide 5'-nontranslated region, an open rea ding frame of 3075 bases, and a 1273 nucleotide 3'-nontranslated regio n. Comparison of the nucleotide and deduced amino acid sequences of Bo vine DPD to Pig and Human liver DPD reveals 93% and 92% identity respe ctively.