Catabolism of Amino Acids and Related Compounds
- Author: Larry Reitzer1
- Editor: Valley Stewart2
VIEW AFFILIATIONS HIDE AFFILIATIONSAffiliations: 1: Department of Molecular and Cell Biology, The University of Texas at Dallas, Richardson, TX 75083-0688; 2: University of California, Davis, Davis, CA
Received 11 January 2005 Accepted 24 March 2005 Published 25 July 2005
- Address correspondence to Larry Reitzer firstname.lastname@example.org
This review considers the pathways for the degradation of amino acids and a few related compounds (agmatine, putrescine, ornithine, and aminobutyrate), along with their functions and regulation. Nitrogen limitation and an acidic environment are two physiological cues that regulate expression of several amino acid catabolic genes. The review considers Escherichia coli, Salmonella enterica serovar Typhimurium, and Klebsiella species. The latter is included because the pathways in Klebsiella species have often been thoroughly characterized and also because of interesting differences in pathway regulation. These organisms can essentially degrade all the protein amino acids, except for the three branched-chain amino acids. E. coli, Salmonella enterica serovar Typhimurium, and Klebsiella aerogenes can assimilate nitrogen from D- and L-alanine, arginine, asparagine, aspartate, glutamate, glutamine, glycine, proline, and D- and L-serine. There are species differences in the utilization of agmatine, citrulline, cysteine, histidine, the aromatic amino acids, and polyamines (putrescine and spermidine). Regardless of the pathway of glutamate synthesis, nitrogen source catabolism must generate ammonia for glutamine synthesis. Loss of glutamate synthase (glutamineoxoglutarate amidotransferase, or GOGAT) prevents utilization of many organic nitrogen sources. Mutations that create or increase a requirement for ammonia also prevent utilization of most organic nitrogen sources.
Citation: Reitzer L. 2005. Catabolism of Amino Acids and Related Compounds, EcoSal Plus 2005; doi:10.1128/ecosalplus.3.4.7