• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >Binding sites and dynamics of ammonium ions in a telomere repeat DNA quadruplex.
【24h】

Binding sites and dynamics of ammonium ions in a telomere repeat DNA quadruplex.

机译：端粒重复DNA四链体中铵离子的结合位点和动力学。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Guanine quartets are readily formed by guanine nucleotides and guanine-rich oligonucleotides in the presence of certain monovalent and divalent cations. The quadruplexes composed of these quartets are of interest for their potential roles in vivo, their relatively frequent appearance in oligonucleotides derived from in vitro selection, and their inhibition of template directed RNA polymerization under proposed prebiotic conditions. The requirement of cation coordination for the stabilization of G quartets makes understanding cation-quadruplex interactions an essential step towards a complete understanding of G quadruplex formation. We have used 15NH4+ as a probe of cation coordination by the four G quartets of the DNA bimolecular quadruplex [d(G4T4G4)]2, formed from oligonucleotides with the repeat sequence found in Oxytricha nova telomeres. 1H and 15N heteronuclear NMR spectroscopy has allowed the direct localization of monovalent cation binding sites in the solution state and the analysis of cation movement between the binding sites. These experiments show that [d(G4T4G4)]2 coordinates three ammonium ions, one in each of two symmetry related sites and one on the axis of symmetry of the dimeric molecule. The NH4+ move along the central axis of the quadruplex between these sites and the solution, reminiscent of an ion channel. The residence time of the central ion is determined to be 250 ms. The 15NH4+ is shown to be a valuable probe of monovalent cation binding sites and dynamics. Copyright 1999 Academic Press.
机译：在某些单价和二价阳离子存在的情况下，鸟嘌呤四联体很容易由鸟嘌呤核苷酸和富含鸟嘌呤的寡核苷酸形成。由这些四重奏组成的四链体因其在体内的潜在作用，它们在源自体外选择的寡核苷酸中相对频繁出现以及在拟议的益生元条件下抑制模板指导的RNA聚合而受到关注。阳离子配位对稳定G四元组的要求使了解阳离子-四链体相互作用成为全面理解G四链体形成的重要步骤。我们已经使用15NH4 +作为DNA双分子四链体[d（G4T4G4）] 2的四个G四重体的阳离子配位探针，该四重体由具有在Oxytricha nova端粒中发现的重复序列的寡核苷酸形成。 1H和15N异核NMR光谱技术可以将单价阳离子结合位点直接定位在溶液状态，并可以分析结合位点之间的阳离子运动。这些实验表明[d（G4T4G4）] 2配位三个铵离子，一个在两个对称相关位点中的每个，一个在二聚体分子的对称轴上。 NH4 +在这些位点和溶液之间沿着四链体的中心轴移动，让人联想到离子通道。确定中心离子的停留时间为250ms。 15NH4 +被证明是单价阳离子结合位点和动力学的有价值的探针。版权所有1999，学术出版社。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号