Molecular cloning of a human cDNA encoding a trifunctional enzyme of carbamoyl-phosphate synthetase-aspartate transcarbamoylase-dihydroorotase in de Novo pyrimidine synthesis

Biochem Biophys Res Commun. 1996 Feb 6;219(1):249-55. doi: 10.1006/bbrc.1996.0213.


A human CAD cDNA encoding a trifunctional enzyme of carbamoylphosphate synthetase-aspartate transcarbamoylase-dihydroorotase, which catalyzes the first three steps of de novo pyrimidine nucleotide biosynthesis, was cloned from a human fibroblast cell line of TIG-1-20 by polymerase chain reaction (PCR). The predicted open reading frame encodes a protein of 2,225 amino acids with a deduced molecular weight (Mr) OF 242,913. The deduced amino acid sequence exhibits 95.3 and 76.1% identity with the CAD sequences of hamster and Squalus acanthias. The DNA fragment of 6,679 bp containing the full-length coding sequence was amplified by nested PCR using the first-strand cDNA of human cell lines of TIG-1-20 and COLO205 as a template. Southern blot analysis suggested that the CAD gene exists as a single copy in the human genome.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aspartate Carbamoyltransferase / biosynthesis*
  • Aspartate Carbamoyltransferase / genetics
  • Base Sequence
  • Blotting, Southern
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / biosynthesis*
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) / genetics
  • Cell Line
  • Cloning, Molecular
  • Cricetinae
  • DNA Primers
  • DNA, Complementary
  • Dihydroorotase / biosynthesis*
  • Dihydroorotase / genetics
  • Dogfish
  • Fibroblasts
  • Humans
  • Molecular Sequence Data
  • Molecular Weight
  • Multienzyme Complexes / biosynthesis*
  • Multienzyme Complexes / genetics
  • Open Reading Frames
  • Polymerase Chain Reaction
  • Pyrimidines / biosynthesis
  • Restriction Mapping
  • Sequence Homology, Amino Acid


  • CAD trifunctional enzyme
  • DNA Primers
  • DNA, Complementary
  • Multienzyme Complexes
  • Pyrimidines
  • Aspartate Carbamoyltransferase
  • Dihydroorotase
  • Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing)

Associated data

  • GENBANK/D78586