title: Partial derepression of the isoleucine-valine enzymes during methionine starvation is Salmonella typhimurium.
abstract: Methionine starvation of methionine auxotrophs in the presence of excess branched-chain amino acids results in a partial derepression of the isoleucine and valine enzymes. Reversed-phase chromatography indicated that isoleucine, valine and leucine tRNA were altered during methionine starvation. In addition, the total tRNA isolated from cells under these conditions were undermethylated. The observed derepression may be caused by the inability of methyl-deficient tRNA's to participate adequately in normal regulatory functions.
mesh_terms: D015079:2-Isopropylmalate Synthase / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism; D007532:Isoleucine / Q000378:metabolism*; D007700:Kinetics; D008715:Methionine / Q000378:metabolism* / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000187:drug effects / Q000201:enzymology*; D013913:Threonine Dehydratase / Q000378:metabolism; D014633:Valine / Q000378:metabolism*
chemical_list: D007532:Isoleucine; D008715:Methionine; D000429:Alcohol Oxidoreductases; D015079:2-Isopropylmalate Synthase; D013913:Threonine Dehydratase; D000604:Amino Acyl-tRNA Synthetases; D014633:Valine