A translational signature for nucleosome positioning in vivo
A translational signature for nucleosome positioning in vivo
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DOI：
10.1093/nar/gkp574
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发表时间：
2009-09-01
影响因子：
14.9
通讯作者：
Travers, Andrew
中科院分区：
文献类型：
--
作者：
Caserta, Micaela;Agricola, Eleonora;Travers, Andrew
体内核小体通常占据基因组 DNA 上明确的首选位置。一个重要的问题是这些首选位置在多大程度上是由 DNA 序列本身直接编码的。我们从体内位置导出，通过部分微球菌核酸酶消化精确绘制，这是一种平移定位信号，可识别组蛋白八聚体结合的 DNA 的大致中点。平均而言，该中点富含 A/T（类似于 73%），特别是，二核苷酸 TpA 优先出现在该凹槽和其他朝外的小凹槽处。我们得出的结论是，在这组序列中，DNA 弯曲和核小体定位的序列代码与其他描述的序列不同，我们建议在中心富集含有 AT 的二核苷酸是局部解旋所必需的。我们表明，该特征优先与启动子区域侧翼的核小体相关，并表明它有助于建立基因特异性核小体阵列。
In vivo nucleosomes often occupy well-defined preferred positions on genomic DNA. An important question is to what extent these preferred positions are directly encoded by the DNA sequence itself. We derive here from in vivo positions, accurately mapped by partial micrococcal nuclease digestion, a translational positioning signal that identifies the approximate midpoint of DNA bound by a histone octamer. This midpoint is, on average, highly A/T rich (similar to 73%) and, in particular, the dinucleotide TpA occurs preferentially at this and other outward-facing minor grooves. We conclude that in this set of sequences the sequence code for DNA bending and nucleosome positioning differs from the other described sets and we suggest that the enrichment of AT-containing dinucleotides at the centre is required for local untwisting. We show that this signature is preferentially associated with nucleosomes flanking promoter regions and suggest that it contributes to the establishment of gene-specific nucleosome arrays.