A packing mechanism for nucleosome organization reconstituted across a eukaryotic genome.
A packing mechanism for nucleosome organization reconstituted across a eukaryotic genome.
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DOI：
10.1126/science.1200508
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发表时间：
2011-05-20
期刊：
影响因子：
--
通讯作者：
Pugh BF
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文献类型：
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作者：
Zhang Z;Wippo CJ;Wal M;Ward E;Korber P;Pugh BF
在大多数真核生物基因的5 '端附近，核小体形成高度规则的阵列，从转录起始点的标准距离开始。这个和基因组核小体组织的其他方面的决定因素被归因于统计定位，内在dna编码定位，或转录起始的某些方面。在这里，我们为另一种解释提供证据。通过三磷酸腺苷依赖的反式作用因子，在大多数酵母基因的5 '端实现了适当的核小体定位、间距和占用水平的生化重建。这些与转录无关的活动覆盖了dna固有的定位，即使在低核小体密度下，也能在基因的5 '端保持均匀的间距。因此，一个活跃的、非统计的核小体包装机制在基因的5 '端产生染色质组织中心，在那里重要的调控元件存在。
Near the 5′ end of most eukaryotic genes, nucleosomes form highly regular arrays that begin at canonical distances from the transcriptional start site. Determinants of this and other aspects of genomic nucleosome organization have been ascribed to statistical positioning, intrinsically DNA-encoded positioning, or some aspect of transcription initiation. Here, we provide evidence for a different explanation. Biochemical reconstitution of proper nucleosome positioning, spacing, and occupancy levels was achieved across the 5′ ends of most yeast genes by adenosine triphosphate–dependent trans-acting factors. These transcription-independent activities override DNA-intrinsic positioning and maintain uniform spacing at the 5′ ends of genes even at low nucleosome densities. Thus, an active, nonstatistical nucleosome packing mechanism creates chromatin organizing centers at the 5′ ends of genes where important regulatory elements reside.