SOLUTION STRUCTURAL STUDIES OF THE AG(I)-DNA COMPLEX
SOLUTION STRUCTURAL STUDIES OF THE AG(I)-DNA COMPLEX
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DOI：
10.1093/nar/9.12.2971
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发表时间：
1981-01-01
影响因子：
14.9
通讯作者：
CROTHERS, DM
中科院分区：
文献类型：
--
作者：
DATTAGUPTA, N;CROTHERS, DM
本文报道了银离子与DNA的两种强配合物（Ⅰ和Ⅱ）的平衡透析和电二色性研究。DNA的合作转换为更强的I型复合物的结果在9%的长度减少，和插入的乙锭是垂直于螺旋轴的结构。在添加更多的Ag+以形成II型复合物时，DNA长度恢复到其原始值，并且结合的乙锭再次从垂直于螺旋轴的平面倾斜。在I型和II型Ag（I）- DNA复合物中，乙锭的结合是温和的协同作用.我们解释的结果在银诱导的合作开关的DNA从它的B-型结构螺旋桨扭曲的碱基对的结构，在I型复杂的结构，并再次回到propellered的碱基对在II型复杂的序列。
We report equilibrium dialysis and electric dichroism studies of the two strong complexes (I and II) of silver ion with DNA. Cooperative conversion of DNA to the stronger type I complex results in a 9% length decrease, and a structure in which intercalated ethidium is perpendicular to the helix axis. Upon addition of more Ag+to form the type II complex, the DNA length reverts to its original value and bound ethidium once again becomes tilted from the plane perpendicular to the helix axis. In both typs I and type II Ag (I) - DNA complexes, ethidium binding is mildly cooperatve. We interpret the results in terms of a sequence of silver-induced cooperative switches of DNA from its B-form structure with propeller twisted base pairs to a structure with flat base pairs in the type I complex, and back again to propellered base pairs in the type II complex.