Deeley R G, Goldberger R F, Kovach J S, Meyers M M, Mullinix K P
Nucleic Acids Res. 1975 Apr;2(4):545-54. doi: 10.1093/nar/2.4.545.
We have examined the interaction between phosphoribosyltransferase and purified tRNA-His from the wild type strain of Salmonella typhimurium, LT-2, and the histidine regulatory mutant hisTl504. Histidyl-tRNA from the mutant strain functions normally in protein synthesis but is defective in its role in the repression mechanism of the histidine operon. Phosphoribosyltransferase has been suggested as a possible aporegulator for this operon and as such might be expected to interact abnormally with tRNA-His from hisT1504. In these studies we have been unable to detect any difference between the affinities of phosphoribosyltransferase for tRNA-His from LT-2 or hisT1504, and thus we conclude that if the complex between phosphoribosyltransferase and histidyl-tRNA does function in regulation, the defect in the hisT1504 mutant must influence the interaction of the complex with some other regulatory element.
我们研究了磷酸核糖基转移酶与来自鼠伤寒沙门氏菌LT-2野生型菌株及组氨酸调节突变体hisT1504的纯化tRNA-His之间的相互作用。来自突变菌株的组氨酰-tRNA在蛋白质合成中功能正常,但在组氨酸操纵子的阻遏机制中其作用存在缺陷。有人提出磷酸核糖基转移酶可能是该操纵子的一种潜在的无辅基调节蛋白,因此可能预期它会与来自hisT1504的tRNA-His发生异常相互作用。在这些研究中,我们未能检测到磷酸核糖基转移酶对来自LT-2或hisT1504的tRNA-His的亲和力之间存在任何差异,因此我们得出结论,如果磷酸核糖基转移酶与组氨酰-tRNA之间的复合物确实在调节中起作用,那么hisT1504突变体中的缺陷必定会影响该复合物与其他一些调节元件的相互作用。