REFINED CRYSTAL-STRUCTURE OF AN OCTANUCLEOTIDE DUPLEX WITH IT MISMATCHED BASE-PAIRS
REFINED CRYSTAL-STRUCTURE OF AN OCTANUCLEOTIDE DUPLEX WITH IT MISMATCHED BASE-PAIRS
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DOI：
10.1093/nar/17.1.55
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发表时间：
1989-01-11
影响因子：
14.9
通讯作者：
LEONARD, GA
中科院分区：
文献类型：
--
作者：
CRUSE, WBT;AYMANI, J;LEONARD, GA
合成的脱氧八聚体d（GGIGCTCC）的结构已通过单晶X-射线衍射技术测定到1.7埃的分辨率。该序列以空间群P61结晶，晶胞尺寸a = B = 45.07，c = 45.49埃。精修收敛于晶体学残差R =-0.14和81个溶剂分子的位置。八聚体形成具有6个Watson-Crick（G. C）碱基对和2个肌苷-胸腺嘧啶（I.T）对的A-DNA双链体。结构的细化表明它基本上是同晶的报告与d（GGGGCCCC）的错对采用“摆动”构象。构象参数和碱基堆积相互作用进行了比较，为天然双链体d（GGGGCCCC）和其他类似的序列。给出了I.T八聚体的晶体堆积效率和晶格稳定性明显增加的基本原理。
The structure of the synthetic deoxyoctamer d(GGIGCTCC) has been determined by single crystal X-ray diffraction techniques to a resolution of 1.7 .ANG.. The sequence crystallises in space group P61, with unit cell dimensions a = b = 45.07, c = 45.49 .ANG.. The refinement converged with a crystallographic residual R = -.14 and the location of 81 solvent molecules. The octamer forms an A-DNA duplex with 6 Watson-Crick (G.C) base pairs and 2 inosine-thymine (I.T) pairs. Refinement of the structure shows it to be essentially isomorphous with that reported for d(GGGGCCCC) with the mispairs adopting a "wobble" conformation. Conformational parameters and base stacking interactions are compared to those for the native duplex d(GGGGCCCC) and other similar sequences. A rationale for the apparent increased crystal packing efficiency and lattice stability of the I.T octamer is given.