title: Evolution of bacterial trp operons and their regulation.
abstract: Survival and replication of most bacteria require the ability to synthesize the amino acid L-tryptophan whenever it is not available from the environment. In this article we describe the genes, operons, proteins, and reactions involved in tryptophan biosynthesis in bacteria, and the mechanisms they use in regulating tryptophan formation. We show that although the reactions of tryptophan biosynthesis are essentially identical, gene organization varies among species--from whole-pathway operons to completely dispersed genes. We also show that the regulatory mechanisms used for these genes vary greatly. We address the question--what are some potential advantages of the gene organization and regulation variation associated with this conserved, important pathway?
authors: Department of Molecular Microbiology, Instituto de Biotecnologia, Universidad Nacional Autonoma de Mexico, Cuernavaca, Morelos 62271, Mexico. merino@ibt.unam.mx
authors: Enrique
authors: E
authors: Merino
authors: Roy A
authors: RA
authors: Jensen
authors: Charles
authors: C
authors: Yanofsky
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D015964:Gene Expression Regulation, Bacterial; D006090:Gram-Negative Bacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006094:Gram-Positive Bacteria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D009876:Operon; D010802:Phylogeny; D014364:Tryptophan / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D014364:Tryptophan