De Anda J, Poteete A R, Sauer R T
J Biol Chem. 1983 Sep 10;258(17):10536-42.
The c2 repressor of bacteriophage P22 can be digested with trypsin, chymotrypsin, or elastase to yield stable fragments. Purified NH2-terminal fragments, like intact repressor, bind specifically to P22 operator DNA and also mediate positive and negative control of transcription. COOH-terminal fragments of repressor do not bind operator DNA but do undergo a concentration-dependent oligomerization similar to that observed with intact repressor. These results suggest that P22 repressor, like the related cI repressor of phage lambda, contains two structural domains which mediate different functions of the intact molecule.
噬菌体P22的c2阻遏物可用胰蛋白酶、胰凝乳蛋白酶或弹性蛋白酶消化，产生稳定的片段。纯化的氨基末端片段，如同完整的阻遏物一样，能特异性地结合P22操纵子DNA，并介导转录的正调控和负调控。阻遏物的羧基末端片段不结合操纵子DNA，但会发生浓度依赖性的寡聚化，类似于在完整阻遏物中观察到的情况。这些结果表明，P22阻遏物与噬菌体λ的相关cI阻遏物一样，包含两个结构域，它们介导完整分子的不同功能。
