Bogosian G, Somerville R L, Nishi K, Kano Y, Imamoto F
Mol Gen Genet. 1984;193(2):244-50. doi: 10.1007/BF00330675.
The expression of the trpR gene of Escherichia coli was investigated by measuring trpR messenger RNA levels in vivo under various physiological conditions. Trp repressor, when present, led to significant decreases in the amount of trpR message produced; this effect was enhanced by providing excess L-tryptophan to the system. In the absence of Trp repressor, no changes in trpR message levels were observed under any of the conditions employed. Sedimentation profiles of trpR mRNA revealed a single species under all circumstances. These results suggest that autogenous repression alone acts to regulate transcription of the trpR gene. The activity of the trpR promoter in vivo was evaluated using a trpR-lacZ operon fusion. Very good agreement was found between relative promoter activity and trpR message levels under all experimental conditions.
通过测量在各种生理条件下大肠杆菌体内色氨酸阻遏蛋白（trpR）信使核糖核酸（mRNA）水平，对大肠杆菌trpR基因的表达进行了研究。色氨酸阻遏蛋白存在时，会导致所产生的trpR信使核糖核酸量显著减少；向系统中提供过量的L-色氨酸可增强这种效应。在没有色氨酸阻遏蛋白的情况下，在所采用的任何条件下均未观察到trpR信使核糖核酸水平的变化。trpR信使核糖核酸的沉降图谱在所有情况下均显示为单一物种。这些结果表明，仅自体阻遏作用就可调节trpR基因的转录。利用trpR-乳糖操纵子融合体评估了trpR启动子在体内的活性。在所有实验条件下，均发现相对启动子活性与trpR信使核糖核酸水平之间具有很好的一致性。
