Liu Hongde, Lin Shuhai, Cai Zongwei, Sun Xiao
School of Biological Science & Medical Engineering, Southeast University, Nanjing, China.
Biosystems. 2011 Sep;105(3):295-9. doi: 10.1016/j.biosystems.2011.05.016. Epub 2011 Jun 22.
10-11bp repeating patterns of the particular dinucleotides were suggested in positioning nucleosomes in eukaryotes. In order to assess the role, the 10-11bp periodicities of the dinucleotides were examined both in human well-positioned nucleosome DNA sequences and in promoter DNA sequences of eight species. Our results indicated that the periodical occurrence of the particular dinucleotides correlates to positioning nucleosome. The signals of 10-11bp periodicities are more pronounced in the nucleosome DNA sequences than in the linker DNA sequences. Near the transcription start site, the signals reveal a similar feature that the nucleosome organization exhibits. But, it seems that the species do not share the same dinucleotides patterns. Furthermore, the dinucleotides patterns are dominant at the specific region of genome, indicating their diverse roles in forming and organizing nucleosomes. Moreover, the 10-11bp periodicities signals near the translation start negatively correlate with gene expression, demonstrating a vital role in transcription regulation. Our study reveals some details about the roles of DNA sequence in positioning nucleosomes.
在真核生物中，特定二核苷酸的10 - 11碱基对重复模式被认为与核小体定位有关。为了评估其作用，研究人员检测了人类定位良好的核小体DNA序列以及八个物种的启动子DNA序列中二核苷酸的10 - 11碱基对周期性。我们的结果表明，特定二核苷酸的周期性出现与核小体定位相关。10 - 11碱基对周期性信号在核小体DNA序列中比在连接子DNA序列中更明显。在转录起始位点附近，这些信号呈现出与核小体组织相似的特征。但是，不同物种似乎并不共享相同的二核苷酸模式。此外，二核苷酸模式在基因组的特定区域占主导地位，表明它们在核小体的形成和组织中具有多种作用。而且，翻译起始位点附近的10 - 11碱基对周期性信号与基因表达呈负相关，证明其在转录调控中起着至关重要的作用。我们的研究揭示了DNA序列在核小体定位中作用的一些细节。
