Rizzino A A, Bresalier R S, Freundlich M
J Bacteriol. 1974 Feb;117(2):449-55. doi: 10.1128/jb.117.2.449-455.1974.
A hisT mutant of Salmonella typhimurium was found to have altered regulation of the isoleucine-valine and leucine enzymes. These enzymes in the hisT strain were derepressed two- to eightfold over those of the parent wild-type strain when grown in minimal medium or under repressing conditions. The amount of tRNA(Leu) and the cellular concentration of charged tRNA(Leu) was about the same in the hisT strain and in the wild type. However, leucyl-tRNA from the mutant was chromatographically different from that of wild type, confirming previous reports that hisT strains have altered tRNA(Leu). These results suggest strongly that tRNA(Leu) is involved in repression of the isoleucine-valine and leucine enzymes in S. typhimurium.
已发现鼠伤寒沙门氏菌的一个hisT突变体对异亮氨酸 - 缬氨酸和亮氨酸酶的调控发生了改变。当在基本培养基中生长或处于阻遏条件下时,hisT菌株中的这些酶比亲本野生型菌株中的酶去阻遏两到八倍。hisT菌株和野生型中tRNA(Leu)的量以及带电荷tRNA(Leu)的细胞浓度大致相同。然而,突变体的亮氨酰 - tRNA在色谱上与野生型不同,证实了之前关于hisT菌株具有改变的tRNA(Leu)的报道。这些结果有力地表明,tRNA(Leu)参与了鼠伤寒沙门氏菌中异亮氨酸 - 缬氨酸和亮氨酸酶的阻遏作用。