Sheppard D E, Eleuterio M, Falgout B
J Bacteriol. 1979 Sep;139(3):1085-8. doi: 10.1128/jb.139.3.1085-1088.1979.
Strains were constructed that contain mutational alterations affecting two distinct functional domains within the araC gene protein. The araCi (catabolite repression insensitivity) and araCh (catabolite repression hypersensitivity) mutations were used to alter the catabolite repression sensitivity domain, and mutation to D-fucose resistance was used to alter the inducer binding domain. araCh, D-fucose-resistant double mutants never exhibited constitutive ara operon expression, whereas all of the araCi, D-fucose-resistant double mutants did exhibit constitutivity. When L-arabinose was used as an inducer, most of the double mutants exhibited the sensitivity to catabolite repression associated with the araCi or araCh mutation. However, when D-fucose was used as an inducer, changes in sensitivity to catabolite repression were observed that were attributed to interactions between the two protein domains. The roles of catabolite activator protein and araC gene protein in the induction of the araBAD operon were discussed.
构建了含有影响araC基因蛋白内两个不同功能域的突变改变的菌株。araCi（分解代谢物阻遏不敏感）和araCh（分解代谢物阻遏超敏感）突变用于改变分解代谢物阻遏敏感域，而对D-岩藻糖抗性的突变用于改变诱导物结合域。araCh、D-岩藻糖抗性双突变体从未表现出组成型ara操纵子表达，而所有araCi、D-岩藻糖抗性双突变体确实表现出组成型。当L-阿拉伯糖用作诱导物时，大多数双突变体表现出与araCi或araCh突变相关的对分解代谢物阻遏的敏感性。然而，当D-岩藻糖用作诱导物时，观察到对分解代谢物阻遏敏感性的变化，这归因于两个蛋白质结构域之间的相互作用。讨论了分解代谢物激活蛋白和araC基因蛋白在araBAD操纵子诱导中的作用。
