Steinberg W
J Bacteriol. 1974 Mar;117(3):1023-34. doi: 10.1128/jb.117.3.1023-1034.1974.
A tryptophanyl-transfer ribonucleic acid (tRNA) synthetase (l-tryptophan: tRNA ligase adenosine monophosphate, EC 6.1.1.2) mutant (trpS1) of Bacillus subtilis is derepressed for enzymes of the tryptophan biosynthetic pathway at temperatures which reduce the growth rate but still allow exponential growth. Derepression of anthranilate synthase in a tryptophan-supplemented medium (50 mug/ml) is maximal at 36 C, and the differential rate of synthesis is 600- to 2,000-fold greater than that of the wild-type strain or trpS1 revertants. A study of the derepression pattern in the mutant and its revertants indicates that the 5-fluorotryptophan recognition site of the tryptophanyl-tRNA synthetase is an integral part of the repression mechanism. Evidence for a second locus, unlinked to the trpS1 locus, which functions in the repression of tryptophan biosynthetic enzymes is presented.
枯草芽孢杆菌的一种色氨酰 - 转移核糖核酸（tRNA）合成酶（L - 色氨酸：tRNA连接酶 单磷酸腺苷，EC 6.1.1.2）突变体（trpS1），在降低生长速率但仍允许指数生长的温度下，色氨酸生物合成途径的酶不受阻遏。在添加色氨酸的培养基（50微克/毫升）中，邻氨基苯甲酸合酶的去阻遏在36℃时最大，其合成差异速率比野生型菌株或trpS1回复突变体大600至2000倍。对该突变体及其回复突变体的去阻遏模式的研究表明，色氨酰 - tRNA合成酶的5 - 氟色氨酸识别位点是阻遏机制的一个组成部分。本文还提出了一个与trpS1位点不连锁的第二个位点的证据，该位点在色氨酸生物合成酶的阻遏中起作用。
