Evolutionary aspects of urea cycle enzyme genes

Bioessays. 1989 May;10(5):163-6. doi: 10.1002/bies.950100506.


The functions and expression pattern of urea cycle enzymes have undergone considerable changes during the course of evolution. Sequence analyses shows that urea cycle enzymes from mammals are homologous to microbial enzymes of the arginine-metabolic pathway. Recently, an unexpected relationship was found between argininosuccinate lyase (EC, the fourth enzyme of the cycle, and delta-crystallin, a lens structural protein of birds and reptiles.

Publication types

  • Review

MeSH terms

  • Animals
  • Arginase / genetics
  • Argininosuccinate Lyase / genetics
  • Argininosuccinate Synthase / genetics
  • Biological Evolution*
  • Carbamoyl-Phosphate Synthase (Ammonia) / genetics
  • Genes*
  • Ornithine Carbamoyltransferase / genetics
  • Urea / metabolism*


  • Urea
  • Ornithine Carbamoyltransferase
  • Arginase
  • Argininosuccinate Lyase
  • Carbamoyl-Phosphate Synthase (Ammonia)
  • Argininosuccinate Synthase