Crystal structure of a DNA decamer showing a novel pseudo four-way helix-helix junction.
Crystal structure of a DNA decamer showing a novel pseudo four-way helix-helix junction.
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DNA 十聚体的晶体结构显示出一种新型的伪四向螺旋-螺旋连接。
DOI：
10.1073/pnas.92.23.10767
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发表时间：
1995
影响因子：
11.1
通讯作者：
Neidle,S
中科院分区：
文献类型：
--
作者：
Spink,N;Nunn,CM;Vojtechovsky,J;Berman,HM;Neidle,S
十核核苷酸d(CGCAATTGCG)2的晶体结构已通过分子置换和重原子方法的结合得到解决，并在2.7 a下被精炼到R因子为20.2%。它不是一个完全碱基配对的双链，但有一个由八个沃森-克里克碱基对组成的中心核心，两侧是未配对的末端鸟苷和胞嘧啶。它们在晶格中与相邻的十聚体双键形成氢键。未配对的鸟苷结合在双小凹槽的G+C区。胞嘧啶具有相对高的流动性，即使它们被限制在一个区域，在那里它们与G.C碱基对组成碱基对的三联体。双区5′-AATT序列具有狭窄的小沟槽，进一步证实了沟槽宽度的序列依赖性。
The crystal structure of the decanucleotide d(CGCAATTGCG)2 has been solved by a combination of molecular replacement and heavy-atom procedures and has been refined to an R factor of 20.2% at 2.7 A. It is not a fully base-paired duplex but has a central core of eight Watson-Crick base pairs flanked by unpaired terminal guanosines and cytosines. These participate in hydrogen-bonding arrangements with adjacent decamer duplexes in the crystal lattice. The unpaired guanosines are bound in the G+C regions of duplex minor grooves. The cytosines have relatively high mobility, even though they are constrained to be in one region where they are involved in base-paired triplets with G.C base pairs. The 5'-AATT sequence in the duplex region has a narrow minor groove, providing further confirmation of the sequence-dependent nature of groove width.