cDNA cloning and chromosome mapping of human dihydropyrimidine dehydrogenase, an enzyme associated with 5-fluorouracil toxicity and congenital thymine uraciluria

• Published in: The Journal of biological chemistry 1994-09, Vol.269 (37), p.23192-23196
• Main Authors: Yokota, H, Fernandez-Salguero, P, Furuya, H, Lin, K, McBride, O W, Podschun, B, Schnackerz, K D, Gonzalez, F J
• Format: Article
• Language: English
• Subjects: 5-fluorouracil; Amino Acid Sequence; amino acid sequence predictions; Animals; Base Sequence; cDNA; chromosome 1; Chromosome Mapping; Chromosomes, Human, Pair 1; Cricetinae; dihydropyrimidine dehydrogenase (NADP super(+)); Dihydrouracil Dehydrogenase (NADP); DNA, Complementary; DPYD gene; Fluorouracil - adverse effects; genes; Humans; Hybrid Cells; man; Metabolism, Inborn Errors - genetics; Mice; Molecular Sequence Data; nucleotide sequence; Oxidoreductases - deficiency; Oxidoreductases - genetics; pigs; Recombinant Proteins - genetics; Swine; thymine; Thymine - urine; uracil; Uracil - urine
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(17)31638-1

The pig and human dihydropyrimidine dehydrogenase (DPD) cDNAs were cloned and sequenced. The pig enzyme, expressed in Escherichia coli, catalyzed the reduction of uracil, thymine, and 5-fluorouracil with kinetics approximating those published for the enzyme purified from mammalian liver. DPD could be expressed in significant quantities only when uracil was added to the bacterial growth medium. The pig and human enzymes contained 1025 amino acids and calculated M(r) = 111,416 and 111,398, respectively. Conserved domains corresponding to a possible NADPH binding site and FAD binding site were found in the NH2-terminal half of the proteins and two motifs of putative [4Fe-4S] binding sites were found near to the carboxyl terminus of the enzyme. The latter corresponds to the labile COOH-terminal fragment previously shown to contain the iron sulfur centers. A sequence encompassing a peptide corresponding to the uracil binding site was found between the NADPH/FAD-containing NH2-terminal portion of the protein and the iron-sulfur binding sites near to the COOH terminus. Thus, the DPD appears to be derived from at least three distinct domains. The DPYD gene was localized to the centromeric region of human chromosome 1 between 1p22 and q21.