title: Regulation of synthesis of the branched-chain amino acids and cognate aminoacyl-transfer ribonucleic acid synthetases of Escherichia coli: a common regulatory element.
abstract: Regulation of isoleucine, valine, and leucine biosynthesis and isoleucyl-, valyl-, and leucyl-transfer ribonucleic acid (tRNA) synthetase formation was examined in two mutant strains of Escherichia coli. One mutant was selected for growth resistance to the isoleucine analogue, ketomycin, and the other was selected for growth resistance to both trifluoroleucine and valine. Control of the synthesis of the branched-chain amino acids by repression was altered in both of these mutants. They also exhibited altered control of formation of isoleucyl-tRNA synthetase (EC 6.1.15, isoleucine:sRNA ligase, AMP), valyl-tRNA synthetase (EC 6.1.1.9, valine:sRNA ligase, AMP), and leucyl-tRNA synthetase (EC 6.1.1.4, leucine:sRNA ligase, AMP). These results suggest the existence of a common element for the control of these two classes of enzymes in Escherichia coli.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000604:Amino Acyl-tRNA Synthetases / Q000096:biosynthesis* / Q000378:metabolism; D002250:Carbon Radioisotopes; D002474:Cell-Free System; D004794:Enzyme Repression; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D005461:Fluorine; D005809:Genes, Regulator; D006836:Hydro-Lyases / Q000378:metabolism; D007532:Isoleucine / Q000031:analogs & derivatives / Q000096:biosynthesis*; D007930:Leucine / Q000031:analogs & derivatives / Q000096:biosynthesis*; D008025:Ligases / Q000378:metabolism; D009154:Mutation; D013912:Threonine; D014633:Valine / Q000096:biosynthesis* / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D002250:Carbon Radioisotopes; D007532:Isoleucine; D005461:Fluorine; D013912:Threonine; D000429:Alcohol Oxidoreductases; D006836:Hydro-Lyases; D008025:Ligases; D000604:Amino Acyl-tRNA Synthetases; D007930:Leucine; D014633:Valine