The Holliday junction in an inverted repeat DNA sequence: Sequence effects on the structure of four-way junctions
The Holliday junction in an inverted repeat DNA sequence: Sequence effects on the structure of four-way junctions
复制标题
DOI：
10.1073/pnas.97.8.3971
复制
发表时间：
2000-04-11
影响因子：
11.1
通讯作者：
Ho, PS
中科院分区：
文献类型：
--
作者：
Eichman, BF;Vargason, JM;Ho, PS
霍利迪连接是重组、病毒整合和DNA修复的重要结构中间体。我们在这里提出的单晶结构的反向重复序列d（CCGGTACCCG）作为霍利迪结在2.1埃的标称分辨率。与之前的晶体结构不同，这种DNA连接具有所有标准沃森-克里克碱基对的B-DNA臂;因此它代表了霍利迪提出的参与同源重组的中间体。该连接是在堆叠的X构象，与两个相互连接的双链体形成的同轴堆叠的臂，并在一个41.4度的角度交叉的右手X，与以前的B-DNA和连接晶体结构的序列比较表明，ACC三核苷酸形成一个稳定的连接在这个系统中的核心。该ACC核心的3 '-C.G碱基对与交叉链处的磷酸盐形成直接和水介导的氢键。该核心内的相互作用限定了霍利迪连接的构象，包括与堆叠的双链体相关的角度以及碱基对如何以连接的稳定形式堆叠。
Holliday junctions are important structural intermediates in recombination, viral integration, and DNA repair. We present here the single-crystal structure of the inverted repeat sequence d(CCGGTACCCG) as a Holliday junction at the nominal resolution of 2.1 Angstrom. Unlike the previous crystal structures, this DNA junction has B-DNA arms with all standard Watson-Crick base pairs; it therefore represents the intermediate proposed by Holliday as being involved in homologous recombination. The junction is in the stacked-X conformation, with two interconnected duplexes formed by coaxially stacked arms, and is crossed at an angle of 41.4 degrees as a right-handed X, A sequence comparison with previous B-DNA and junction crystal structures shows that an ACC trinucleotide forms the core of a stable junction in this system. The 3'-C.G base pair of this ACC core forms direct and water-mediated hydrogen bonds to the phosphates at the crossover strands. Interactions within this core define the conformation of the Holliday junction, including the angle relating the stacked duplexes and how the base pairs are stacked in the stable form of the junction.