Kuhn J C, Pabst M J, Somerville R L
J Bacteriol. 1972 Oct;112(1):93-101. doi: 10.1128/jb.112.1.93-101.1972.
Eighteen mutants (designated MT(s)), isolated in Escherichia coli K-12, showed increased sensitivity to inhibition of growth by 5-methyltryptophan. All mutants were also much more sensitive to 4-methyltryptophan and 7-azatryptophan but exhibited near normal sensitivity to 5-fluorotryptophan and 6-fluorotryptophan. All of the mutations were linked to the trp operon. Their locations within the trp operon were established by deletion mapping. There was good agreement between the map position of an MT(s) mutation and a lowered activity of one of the tryptophan pathway enzymes. Three mutants, one of which contained a mutation that mapped within the trpE gene, were deficient in their ability to use glutamine as an amino donor in the formation of anthranilic acid. Another trpE mutation led to the production of an anthranilate synthetase with an increased sensitivity to feedback inhibition by tryptophan.
在大肠杆菌K-12中分离出的18个突变体（命名为MT(s)）对5-甲基色氨酸抑制生长表现出更高的敏感性。所有突变体对4-甲基色氨酸和7-氮杂色氨酸也更为敏感，但对5-氟色氨酸和6-氟色氨酸表现出接近正常的敏感性。所有突变均与色氨酸操纵子相关。通过缺失作图确定了它们在色氨酸操纵子中的位置。MT(s)突变的图谱位置与色氨酸途径中一种酶活性降低之间存在良好的一致性。三个突变体，其中一个含有定位在trpE基因内的突变，在利用谷氨酰胺作为氨基供体形成邻氨基苯甲酸的能力上存在缺陷。另一个trpE突变导致产生一种对色氨酸反馈抑制敏感性增加的邻氨基苯甲酸合成酶。
