Removal of a single minor-groove functional group eliminates A-tract curvature.
Removal of a single minor-groove functional group eliminates A-tract curvature.
复制标题
去除单个小凹槽官能团可消除 A 束弯曲。
DOI：
10.1021/ja0632310
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发表时间：
2006
影响因子：
15
通讯作者：
L. McLaughlin
中科院分区：
文献类型：
--
作者：
Meena;Zhenhua Sun;C. Mulligan;L. McLaughlin
在研究A道曲率现象的工作中，大部分涉及将修饰的残基插入A道序列中，然后将结构差异与所产生的曲率效应互相关。在A段序列d（A-T）5中，通过用氢取代来去除单个官能团（中心dT残基的O2-羰基）完全消除了曲率性质。这种原子特异性的变化是通过使用C-核苷dm 32 P完成的，其中O2-羰基被-H取代，但保持正常的沃森-克里克氢键。当中心dT残基存在时，具有-F（dF 62 P）或-CH 3（dm 62 P）的类似衍生物也消除曲率。最后，我们已经表明，含有这种羰基的序列的曲率的程度是敏感的[Mg 2 +]，而那些缺乏羰基显示很少或没有Mg 2+的依赖性，强烈建议，我们相信，在小沟中的Na+/Mg 2+合作相互作用的作用，以解释曲率现象。
Much of the work in studying the phenomenon of A-tract curvature has involved the insertion of modified residues into the A-tract sequence and then cross-correlation of the structural differences with the resulting curvature effects. In the A-tract sequence d(A-T)5, removal of a single functional group (the O2-carbonyl of the central dT residue) by its replacement with hydrogen completely eliminates the curvature properties. This atom-specific change was accomplished by using the C-nucleoside dm32P in which the O2-carbonyl is replaced with -H but normal Watson-Crick hydrogen bonding is maintained. Similar derivatives with -F (dF62P) or -CH3 (dm62P) when present for the central dT residue also eliminate curvature. Finally, we have shown that the extent of curvature for sequences containing this carbonyl are sensitive to the [Mg2+], while those lacking the carbonyl show little to no Mg2+ dependence, strongly suggesting, we believe, a role for Na+/Mg2+ cooperative interactions in the minor groove to explain the curvature phenomenon.