Eckdahl T T, Anderson J N
Department of Biological Sciences, Purdue University, West Lafayette, IN 47907.
Nucleic Acids Res. 1990 Mar 25;18(6):1609-12. doi: 10.1093/nar/18.6.1609.
According to the model of Bramhill and Kornberg, initiation of DNA replication in prokaryotes involves binding of an initiator protein to origin DNA and subsequent duplex opening of adjacent direct repeat sequences. In this report, we have used computer analysis to examine the higher-order DNA structure of a variety of origins of replication from plasmids, phages, and bacteria in order to determine whether these sequences are localized in domains of altered structure. The results demonstrate that the primary sites of initiator protein binding lie in discrete domains of DNA bending, while the direct repeats lie within well-defined boundaries of an unusual anti-bent domain. The anti-bent structures arise from a periodicity of A3 and T3 tracts which avoids the 10-11 bp bending periodicity. Since DNA fragments which serve as replicators in yeast also contain these two conserved structural elements, the results provide new insight into the universal role of conserved DNA structures in DNA replication.
根据布拉姆希尔和科恩伯格的模型，原核生物中DNA复制的起始涉及起始蛋白与起始DNA的结合以及随后相邻直接重复序列的双链打开。在本报告中，我们使用计算机分析来检查来自质粒、噬菌体和细菌的各种复制起始位点的高阶DNA结构，以确定这些序列是否定位在结构改变的区域。结果表明，起始蛋白结合的主要位点位于DNA弯曲的离散区域，而直接重复序列位于一个不寻常的抗弯曲区域的明确边界内。抗弯曲结构源于A3和T3序列的周期性，避免了10 - 11 bp的弯曲周期性。由于在酵母中作为复制子的DNA片段也包含这两个保守的结构元件，这些结果为保守DNA结构在DNA复制中的普遍作用提供了新的见解。
