Metzler W J, Arndt K, Tecza E, Wasilewski J, Lu P
Biochemistry. 1985 Mar 12;24(6):1418-24. doi: 10.1021/bi00327a020.
The experiments here show that chemically synthesized DNA containing fluorine at selected sites can be used to test specific predictions of a model for cro repressor--operator interaction. This is done by observation of the perturbation to the fluorine-19 NMR spectra of analogues of OR3 synthesized with 2'-deoxy-5-fluorouracil at specific positions in the DNA helix. Although the three-dimensional structure of the cro repressor from phage lambda has been determined by Matthews and co-workers [Anderson, W., Ohlendorf, D., Takeda, Y., & Matthews, B. (1981) Nature (London) 290, 754-758], direct structural observations on the complex of the protein with its specific DNA recognition sequence, OR3, are limited. From that structure of the protein, alone, a model of its complex to DNA was built by fitting B-form DNA, with some distortion [Ohlendorf, D., Anderson, W., Fisher, R., Takeda, Y., & Matthews, B. (1982) Nature (London) 298, 718-723]. That model proposes that the cro repressor contacts only one side of this DNA double helix and a number of specific protein--DNA contacts. To test the model, 2'-deoxy-5-fluorouracil was used to place the fluorine-19 nuclear spin-label on the side of the DNA contacting the cro repressor and on the opposite side facing away from the cro repressor. The results presented here are consistent with the prediction that lambda phage cro repressor contacts only one side of the DNA double helix.
此处的实验表明，在选定位置含有氟的化学合成DNA可用于测试cro阻遏蛋白与操纵基因相互作用模型的特定预测。这是通过观察用2'-脱氧-5-氟尿嘧啶在DNA螺旋特定位置合成的OR3类似物的氟-19核磁共振谱的扰动来实现的。尽管噬菌体λ的cro阻遏蛋白的三维结构已由马修斯及其同事确定[安德森，W.，奥尔登多夫，D.，武田，Y.，&马修斯，B.（1981年）《自然》（伦敦）290，754 - 758]，但关于该蛋白质与其特定DNA识别序列OR3复合物的直接结构观察有限。仅根据该蛋白质的结构，通过拟合B型DNA构建了其与DNA复合物的模型，存在一些扭曲[奥尔登多夫，D.，安德森，W.，费舍尔，R.，武田，Y.，&马修斯，B.（1982年）《自然》（伦敦）298，718 - 723]。该模型提出cro阻遏蛋白仅与该DNA双螺旋的一侧接触以及一些特定的蛋白质 - DNA接触。为了测试该模型，使用2'-脱氧-5-氟尿嘧啶将氟-19核自旋标记置于与cro阻遏蛋白接触的DNA一侧以及背离cro阻遏蛋白的另一侧。此处呈现的结果与λ噬菌体cro阻遏蛋白仅与DNA双螺旋一侧接触的预测一致。
