title: The relA locus and the regulation of lysine biosynthesis in Escherichia coli.
abstract: The allelic state of relA influences the phenotype of Escherichia coli strains carrying the lysA22 mutation:lysA22 relA strains are Lys- where lysA22 relA+ strains grow (slowly) in the absence of lysine. This physiological effect has been related to an effect of the expression of the relA locus on the regulation of lysine biosynthesis. The fully derepressed levels of some lysine enzymes (aspartokinase III, aspartic semialdehyde dehydrogenase, didhydrodipicolinate reductase) are observed under lysine limitation only in rel+ strains. And the induction of DAP-decarboxylase by DAP is much higher in rel+ than in rel- strains when an amino acid limitation of growth is also realised. These results are in agreement with the hypothesis of Stephens et al. (1975) on a possible role of the stringent regulation as a general signal for amino acid deficiency.
mesh_terms: D001222:Aspartate Kinase / Q000235:genetics; D001223:Aspartate-Semialdehyde Dehydrogenase / Q000235:genetics; D001426:Bacterial Proteins; D002262:Carboxy-Lyases / Q000235:genetics; D050746:Dihydrodipicolinate Reductase; D004926:Escherichia coli / Q000235:genetics*; D001277:GTP Pyrophosphokinase / Q000235:genetics* / Q000502:physiology; D005786:Gene Expression Regulation; D008239:Lysine / Q000096:biosynthesis / Q000235:genetics*; D010088:Oxidoreductases / Q000235:genetics; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010770:Phosphotransferases / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D010088:Oxidoreductases; D050746:Dihydrodipicolinate Reductase; D001223:Aspartate-Semialdehyde Dehydrogenase; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010770:Phosphotransferases; D001222:Aspartate Kinase; D001277:GTP Pyrophosphokinase; D002262:Carboxy-Lyases; C079912:LysA protein, Bacteria; C020031:diaminopimelic acid decarboxylase; D008239:Lysine