Segal Eran, Widom Jonathan
Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, 76100, Israel.
Curr Opin Struct Biol. 2009 Feb;19(1):65-71. doi: 10.1016/j.sbi.2009.01.004. Epub 2009 Feb 7.
Homopolymeric stretches of deoxyadenosine nucleotides (A's) on one strand of double-stranded DNA, referred to as poly(dA:dT) tracts or A-tracts, are overabundant in eukaryotic genomes. They have unusual structural, dynamic, and mechanical properties, and may resist sharp bending. Such unusual material properties, together with their overabundance in eukaryotes, raised the possibility that poly(dA:dT) tracts might function in eukaryotes to influence the organization of nucleosomes at many genomic regions. Recent genome-wide studies strongly confirm these ideas and suggest that these tracts play major roles in chromatin organization and genome function. Here we review what is known about poly(dA:dT) tracts and how they work.
双链DNA一条链上的脱氧腺苷核苷酸（A）的同聚物片段，即所谓的聚（dA:dT）序列或A序列，在真核生物基因组中含量过高。它们具有不同寻常的结构、动力学和机械特性，可能会抵抗急剧弯曲。这些不同寻常的物质特性，以及它们在真核生物中的过量存在，引发了一种可能性，即聚（dA:dT）序列可能在真核生物中发挥作用，影响许多基因组区域核小体的组织。最近的全基因组研究有力地证实了这些观点，并表明这些序列在染色质组织和基因组功能中发挥着重要作用。在这里，我们综述了关于聚（dA:dT）序列的已知信息以及它们的作用方式。
