Repression of Enzymes of Arginine Biosynthesis by l-Canavanine in Arginyl-Transfer Ribonucleic Acid Synthetase Mutants of Escherichia coli

摘要: We show that the arginine analogue, l-canavanine, repressed accumulation of translatable messenger ribonucleic acid (RNA) for three biosynthetic enzymes in Escherichia coli. The method used to determine level RNA depended upon measurement a burst enzyme synthesis as described previously. E. coli strains with defective arginyltransfer (tRNA) synthetase (argS mutants) were insensitive canavanine repression. When deprived leucine, leu argS strain regained normal sensitivity vivo canavanyl-tRNAarg was determined and an mutant. After 20 min growth only 9% tRNAarg from protected periodate oxidation, while 42% argS+ charged. or grown contained more than 60% charged tRNAarg. Reverse phase column chromatography periodate-oxidized tRNA canavanine-grown showed no preferential charging any isoaccepting species Therefore, we failed detect specific arginyl-tRNA might be involved repression by canavanine. However, data suggest pathway occurs when high levels canavanyl-tRNA are present, thus support notion plays role generating signal.