Reactome: A Curated Pathway Database

Pyrimidine catabolism

Stable Identifier
Homo sapiens
Locations in the PathwayBrowser

In parallel sequences of three reactions each, thymine is converted to beta-aminoisobutyrate and uracil is converted to beta-alanine. Both of these molecules are excreted in human urine and appear to be normal end products of pyrimidine catabolism (Griffith 1986; Webster et al. 2001). Mitochondrial AGXT2, however, can also catalyze the transamination of both molecules with pyruvate, yielding 2-oxoacids that can be metabolized further by reactions of branched-chain amino acid and short-chain fatty acid catabolism (Tamaki et al. 2000). The importance of these reactions in normal human pyrimidine catabolism has not been well worked out.

Literature References
PubMed ID Title Journal Year
3090932 Beta-amino acids: mammalian metabolism and utility as alpha-amino acid analogues Annu Rev Biochem 1986
10989446 Purification, properties, and sequencing of aminoisobutyrate aminotransferases from rat liver Methods Enzymol 2000
  The Metabolic and Molecular Bases of Inherited Disease, 8th ed   2001
Participant Of
Orthologous Events