Duplex-hairpin transitions in DNA: NMR studies on CGCGTATACGCG.
Duplex-hairpin transitions in DNA: NMR studies on CGCGTATACGCG.
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DNA 中的双链发夹转变：CGCGTATACGCG 的 NMR 研究。
DOI：
10.1093/nar/13.10.3755
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发表时间：
1985
影响因子：
14.9
通讯作者：
Reid,BR
中科院分区：
文献类型：
--
作者：
Wemmer,DE;Chou,SH;Hare,DR;Reid,BR
二维核磁共振方法已被用于指认高盐(>；100 mM Na+)，低温双链形式的自互补DNA十二聚体d(CGTATACGCG)中的质子共振。在低盐(<；10 mM Na+)和较高温度下，分子的二维谱和一维谱都发生了明显的变化，表明该分子转变为另一种构象。利用饱和转移方法，对这一新构象的许多共振峰进行了归属，并研究了这两种构象相互转化的动力学。这种交替构象形成的线宽、关联时间和浓度依赖关系支持它是单分子发夹的观点。通过观察发夹构象中的化学位移和NOE，可以进行一些初步的结构表征。对相互转化的能量学的研究表明，形式之间的交换不是通过单链中间体进行的，而是通过另一条途径进行的，可能涉及十字形结构。
Two dimensional NMR, methods have been used to assign proton resonances in the high salt (>100mM Na+), low temperature duplex form of the self-complementary DNA dodecamer d(CGCGTATACGCG). At low salt (< 10mM Na+) and higher temperature marked changes in the two-dimentional spectrum, and in the one-dimensional spectrum reported by others, indicate that the molecule converts to an alternate conformation. Using saturation transfer methods, many of the resonances of this new conformation have been assigned, and the kinetics of the interconversion of the two forms has been studied. The linewidth, correlation time, and concentration dependence of the formation of this alternate conformation support the idea that it is a unimolecular hairpin. Observation of chemical shifts and NOEs in the hairpin conformation allow some preliminary structural characterization. Examination of the energetics of the interconversion suggests that the exchange between forms does not proceed through a single stranded intermediate, but rather through another pathway, probably involving a cruciform structure.