title: Regulation of tyrosine and phenylalanine biosynthesis in Escherichia coli K-12: properties of the tyrR gene product.
abstract: A spontaneous amber tyrR mutant has been isolated in which constitutive synthesis of 3-deoxy-d-arabinoheptulosonic acid 7-phosphate (DAHP) synthetase (tyr) and DAHP synthetase (phe) is suppressible by supC(-), supD(-), supF(-) and supU(-). This finding suggests the tyrR gene product is a protein. Derepression of DAHP synthetase (phe) in this and in seven other spontaneous tyrR mutants and in four Mu-1-induced tyrR mutants provides further evidence for the involvement of the tyrR gene product in phenylalanine biosynthesis. Evidence that the tyrR product is a component of repressor, rather than an enzyme involved in its synthesis or modification, comes from a study of a temperature-sensitive tyrR mutant. This mutant is of the thermolabile type, since derepression occurs rapidly and in the presence and absence of growth.
mesh_terms: D000446:Aldehyde-Lyases / Q000096:biosynthesis; D001426:Bacterial Proteins; D002474:Cell-Free System; D003090:Coliphages / Q000254:growth & development; D004352:Drug Resistance, Microbial; D004794:Enzyme Repression; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005461:Fluorine / Q000494:pharmacology; D005809:Genes, Regulator; D006539:Heptoses; D007527:Isoenzymes / Q000096:biosynthesis; D008242:Lysogeny; D009153:Mutagens; D009154:Mutation; D009604:Nitrosoguanidines; D010649:Phenylalanine / Q000096:biosynthesis*; D013696:Temperature; D013780:Tetroses; D014161:Transduction, Genetic; D014443:Tyrosine / Q000096:biosynthesis* / Q000494:pharmacology
chemical_list: D001426:Bacterial Proteins; D006539:Heptoses; D007527:Isoenzymes; D009153:Mutagens; D009604:Nitrosoguanidines; D013780:Tetroses; D005461:Fluorine; D014443:Tyrosine; D010649:Phenylalanine; D000446:Aldehyde-Lyases