Specific interactions of divalent metal ions with a DNA duplex containing the d(CA)n/(GT)n tandem repeat.
Specific interactions of divalent metal ions with a DNA duplex containing the d(CA)n/(GT)n tandem repeat.
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二价金属离子与含有 d(CA)n/(GT)n 串联重复序列的 DNA 双链体的特异性相互作用。
DOI：
10.1080/07391102.2006.10507091
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Russu,IrinaM
中科院分区：
文献类型：
--
作者：
Griffiths,KerenK;Russu,IrinaM
二价金属离子对于维持DNA分子的功能状态是必不可少的。它们在DNA结构中的参与由碱基序列调节，并根据离子的性质而变化。本研究解决了两个CA二核苷酸，（CA）2/（TG）2的串联重复的Ca 2+离子的相互作用。通过使用化学位移映射的核磁共振（NMR）光谱监测Ca 2+与重复的结合。平行实验监测Mg 2+离子与重复序列的结合以及每个离子与其中（CA）2/（TG）2重复序列被消除的DNA双链体的结合。结果表明，Ca ~（2+）和Mg ~（2+）引起的化学位移变化的方向和幅度不同。通过消除（CA）2/（TG）2重复序列，两种阳离子之间的差异显著减小。这些结果表明Ca ~（2+）与（CA）_2/（TG）_2基序之间存在特异性的相互作用。这种相互作用的特异性在于重复序列的两个A-T碱基对，并且它涉及第一个A-T碱基对的大沟和第二个A-T碱基对的两个沟。
Divalent metal ions are essential for maintaining functional states of the DNA molecule. Their participation in DNA structure is modulated by the base sequence and varies depending on the nature of the ion. The present investigation addresses the interaction of Ca2+ions with a tandem repeat of two CA dinucleotides, (CA)2/(TG)2. The binding of Ca2+to the repeat is monitored by nuclear magnetic resonance (NMR) spectroscopy using chemical shift mapping. Parallel experiments monitor binding of Mg2+ions to the repeat as well as binding of each ion to a DNA duplex in which the (CA)2/(TG)2repeat is eliminated. The results reveal that the direction and the magnitude of chemical shift changes induced by Ca2+ions in the NMR spectra of the repeat are different from those induced by Mg2+ions. The differences between the two cations are significantly diminished by the elimination of the (CA)2/(TG)2repeat. These findings suggest a specific interaction of Ca2+ions with the (CA)2/(TG)2motif. The specificity of the interaction resides in the two A-T base pairs of the repeat, and it involves the major groove of the first A-T base pair and both grooves of the second A-T base pair.