Nucleosome packaging and nucleosome positioning of genomic DNA
Nucleosome packaging and nucleosome positioning of genomic DNA
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DOI：
10.1073/pnas.94.4.1183
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发表时间：
1997-02-18
影响因子：
11.1
通讯作者：
Widom, J
中科院分区：
文献类型：
--
作者：
Lowary, PT;Widom, J
本研究的目的是评估基因组DNA序列在核小体中的包装程度，并揭示核小体包装与定位之间的关系。利用竞争性核小体重建试验，我们发现至少95%的基因组DNA序列对核小体中的组蛋白八聚体具有与随机合成DNA相似的亲和力;它们在单个核小体的水平上对其自身的包装贡献很小。开发了一个方程，该方程将所测量的自由能与特定核小体位置的占有率相关联。显然，真核基因组DNA的大部分也不进化或约束于在单个核小体水平上的显著序列指导的核小体定位。在体内基因调控的影响进行了讨论。
The goals of this study were to assess the extent to which bulk genomic DNA sequences contribute to their own packaging in nucleosomes and to reveal the relationship between nucleosome packaging and positioning, Using a competitive nucleosome reconstitution assay, we found that at least 95% of bulk DNA sequences have an affinity for histone octamer in nucleosomes that is similar to that of randomly synthesized DNA; they contribute little to their own packaging at the level of individual nucleosomes. An equation was developed that relates the measured free energy to the fractional occupancy of specific nucleosome positions, Evidently, the bulk of eukaryotic genomic DNA is also not evolved or constrained for significant sequence-directed nucleosome positioning at the level of individual nucleosomes. Implications for gene regulation in vivo are discussed.