Direct interactions between Z-DNA and alkaline earth cations, discovered in the presence of high concentrations of MgCl2 and CaCl2
Direct interactions between Z-DNA and alkaline earth cations, discovered in the presence of high concentrations of MgCl2 and CaCl2
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DOI：
10.1016/j.jinorgbio.2013.03.004
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发表时间：
2013-07-01
影响因子：
3.9
通讯作者：
Sunami, Tomoko
中科院分区：
文献类型：
--
作者：
Chatake, Toshiyuki;Sunami, Tomoko
在本研究中，利用温度控制技术，在高浓度碱土盐(500 MM)存在下，获得了六聚体与氯化镁和氯化钙的络合晶体，并在1.3埃分辨率下测定了它们的晶体结构。这些结构中的镁和钙离子倾向于直接与Z-DNA双链体的磷酸基团相互作用：然而，在较低浓度的碱土盐存在下，它们倾向于与Z-DNA形成水介导的相互作用。在这些晶体中，一个DNA双链沿其c轴排列，并通过P-O-中心点、中心点、中心点(Mg2+或Ca2+)(中心点、中心点、中心点)O-P的配位键与相邻的6个DNA双链相互作用。一个对称的六方Z-DNA双链组装模型可以解释碱土盐类引起的DNA缩合。这些结构揭示了碱土阳离子对Z-DNA双链的结构和组装所必需的功能。(C)2013 Elsevier Inc.保留所有权利。
In this study, crystals of Z-DNA hexamer d(CGCGCG) complexed with MgCl2 and CaCl2 were obtained in the presence of high concentrations of alkaline earth salts (500 mM) using a temperature control technique, and their crystal structures were determined at 1.3 angstrom resolution. Mg2+ and Ca2+ cations in these structures tend to interact directly with phosphate groups of Z-DNA duplexes: however, they tend to form water-mediated interactions with Z-DNA in the presence of lower concentrations of alkaline earth salts. In these crystals, a DNA duplex was laid along its c-axis and interacted with its 6 neighboring DNA duplexes through coordination bonds of P-O-center dot center dot center dot(Mg2+ or Ca2+)(center dot center dot center dot)O-P. A symmetrical hexagonal Z-DNA duplex assembly model may explain DNA condensation caused by alkaline earth salts. These structures offer insights into the functions of alkaline earth cations essential to the structures and assembly of Z-DNA duplexes. (C) 2013 Elsevier Inc. All rights reserved.