Woodson S A, Crothers D M
Biopolymers. 1989 Jun;28(6):1149-77. doi: 10.1002/bip.360280608.
Two-dimensional nmr data on a bulge-containing oligodeoxyribonucleotide, 5'dGATGGGCAG.dCTGACCCATC, and a regular oligomer of similar sequence, 5'dGATGGCAG.dCTGCCATC, are presented. The nonexchangeable protons are assigned from sequential nuclear Overhauser effect spectroscopy (NOESY) connectivities. The two-dimensional NOE (NOESY) and correlated (COSY) spectra of the bulge-containing oligomer are compared to those of the perfect 8-mer. Experimental proton-proton distances are determined from NOESY spectra acquired with mixing times of 100, 150, and 200 ms, using comparable distances in the B-DNA region of the molecule as a calibration. With this approach, measured distances do not depend systematically on mixing time. Energy minimization techniques are used to calculate a three-dimensional structure for the bulge-containing oligomer in agreement with the nmr data. The helix is of the B family, with the extra adenine stacked into the helix, and the helix axis is bent by 20 degrees.
本文给出了一段含凸起的寡脱氧核糖核苷酸5'dGATGGGCAG.dCTGACCCATC以及一段序列相似的规则寡聚物5'dGATGGCAG.dCTGCCATC的二维核磁共振数据。通过序列核Overhauser效应光谱法（NOESY）的连接关系对不可交换质子进行了归属。将含凸起寡聚物的二维NOE（NOESY）光谱和相关（COSY）光谱与完美8聚体的光谱进行了比较。使用分子B-DNA区域中的可比距离作为校准，从混合时间分别为100、150和200毫秒的NOESY光谱中确定了实验质子-质子距离。采用这种方法，测量距离并不系统地依赖于混合时间。使用能量最小化技术计算了与核磁共振数据一致的含凸起寡聚物的三维结构。该螺旋属于B型家族，额外的腺嘌呤堆积在螺旋中，螺旋轴弯曲了20度。
