title: Metabolites influence control of lysine transfer ribonucleic acid synthetase formation in Escherichia coli K-12.
abstract: A mutant of E. coli K-12 has been isolated which has only 1-3% of the wild-type lysyl-tRNA synthetase activity [L-lysine:tRNA ligase (AMP forming), EC 6.1.1.6]. Additions of 20 mM L-alanine or 6 mM leucine dipeptides to the culture medium can restore the activity of lysyl-tRNA  synthetase in the mutant strain to the wild-type level. Experiments on the in vivo charging of lysine tRNA in the mutant show that in the absence of the metabolites lysine tRNA is charged 15-23%. Upon the addition of 3 mM L-leucyl-L-alanine to the medium the lysyl tRNA synthetase activity increases 25-fold and the in vivo charging of lysine tRNA returns to the wild-type level. Experiments with antibody against lysyl-tRNA synthetase show that the stimulation of lysyl-tRNA synthetase activity by the metabolites is the result of new protein synthesis.
mesh_terms: D000409:Alanine / Q000494:pharmacology; D000604:Amino Acyl-tRNA Synthetases / Q000096:biosynthesis*; D000818:Animals; D000937:Antigen-Antibody Reactions; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D005779:Immunodiffusion; D007930:Leucine / Q000494:pharmacology; D008250:Lysine-tRNA Ligase / Q000096:biosynthesis* / Q000276:immunology; D009154:Mutation; D011817:Rabbits / Q000276:immunology; D046249:Transfer RNA Aminoacylation / Q000187:drug effects
chemical_list: D000604:Amino Acyl-tRNA Synthetases; D008250:Lysine-tRNA Ligase; D007930:Leucine; D000409:Alanine