Beyond Sequence: Internucleosomal Interactions Dominate Array Assembly
Beyond Sequence: Internucleosomal Interactions Dominate Array Assembly
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DOI：
10.1021/acs.jpcb.2c05321
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发表时间：
2022-12-14
影响因子：
3.3
通讯作者：
Lyubchenko，Yuri L.
中科院分区：
文献类型：
--
作者：
Wang，Yaqing;Stormberg，Tommy;Lyubchenko，Yuri L.
核小体阵列的组织是染色质组装成更高级结构及其功能的关键组成部分。在这里，我们研究的DNA序列和internucleosomal相互作用的组织核小体阵列在紧凑的结构，使用原子力显微镜的贡献。我们在DNA底物上组装核小体，从而形成四核小体。我们发现，核小体能够紧密定位，它们之间没有明显的空间，即使在组装的双核小体的情况下。阵列的这种形态与观察到的由均匀间隔区分开的核小体定位基序的重复组装的阵列形成对比。模拟组装的四个核小体随机放置沿着基板显示，核小体阵列压实促进核小体的相互作用。我们建立了一个理论模型来解释DNA序列和核小体间相互作用在核小体结构形成中的作用。这些发现表明，在染色质组装，核小体的DNA序列的亲和力和核小体间的相互作用的强度是两个主要因素定义的染色质的紧凑性。
The organization of the nucleosome array is a critical component of the chromatin assembly into higher order structure as well as its function. Here, we investigated the contributions of the DNA sequence and internucleosomal interactions on the organization of the nucleosomal arrays in compact structures using atomic force microscopy. We assembled nucleosomes on DNA substrates allowing for the formation of tetranucleosomes. We found that nucleosomes are capable of close positioning with no discernible space between them, even in the case of assembled dinucleosomes. This morphology of the array is in contrast with that observed for arrays assembled with repeats of the nucleosome positioning motifs separated by uniform spacers. Simulated assembly of tetranucleosomes by random placement along the substrates revealed that nucleosome array compaction is promoted by the interaction of the nucleosomes. We developed a theoretical model to account for the role of DNA sequence and internucleosomal interactions in the formation of the nucleosome structures. These findings suggest that, in the chromatin assembly, the affinity of the nucleosomes to the DNA sequence and the strengths of the internucleosomal interactions are the two major factors defining the compactness of the chromatin.