Mattern I E, Pittard J
J Bacteriol. 1971 Jul;107(1):8-15. doi: 10.1128/jb.107.1.8-15.1971.
Mutant strains of Escherichia coli have been isolated in which the synthesis of two of the enzymes involved in tyrosine biosynthesis, 3-deoxy-d-arabinoheptulosonic acid-7 phosphate synthetase (tyr) and chorismate mutase T-prephenate dehydrogenase, is partially constitutive. The mutations involved are closely linked to aroF and tyrA, the structural genes of these enzymes. The gene in which the mutations occur has been designated aroK, and the gene sequence is aroK, aroF, tyrA. In aroK(+)/aroK diploids, the aroK allele only affects the structural genes in the cis position. The mutant allele aroK is not recessive to aroK(+) and aroK/aroK(+) strains exhibit the aroK phenotype of resistance to 4-aminophenylalanine. It is proposed that aroK is an operator locus for an aroF tyrA operon.
已分离出大肠杆菌的突变菌株，其中参与酪氨酸生物合成的两种酶，即3-脱氧-D-阿拉伯庚酮糖酸-7-磷酸合成酶（tyr）和分支酸变位酶-对羟基苯丙酮酸脱氢酶的合成部分呈组成型。所涉及的突变与这些酶的结构基因aroF和tyrA紧密连锁。发生突变的基因已被命名为aroK，基因序列为aroK、aroF、tyrA。在aroK(+)/aroK二倍体中，aroK等位基因仅影响顺式位置的结构基因。突变等位基因aroK对aroK(+)不是隐性的，aroK/aroK(+)菌株表现出对4-氨基苯丙氨酸抗性的aroK表型。有人提出aroK是aroF tyrA操纵子的一个操纵基因位点。
