Supercoiling-dependent flexibility of adenosine-tract-containing DNA detected by a topological method.
Supercoiling-dependent flexibility of adenosine-tract-containing DNA detected by a topological method.
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通过拓扑方法检测含腺苷段 DNA 的超螺旋依赖性灵活性。
DOI：
10.1073/pnas.94.7.2817
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发表时间：
1997
影响因子：
11.1
通讯作者：
Levene,SD
中科院分区：
文献类型：
--
作者：
Tsen,H;Levene,SD
内在弯曲的 DNA 序列通过促进超螺旋结构域末端环附近的 DNA 序列并置而参与转录激活。我们开发了一种基于 λ 整合重组的新型 DNA 环拓扑分析方法，以研究固有弯曲 DNA 序列对负超螺旋 DNA 三级结构的影响。值得注意的是，超螺旋质粒末端环中腺苷束（A-tract）序列的定位与内在弯曲的程度无关。结果表明，除了固有弯曲之外，包含A-tract的序列还具有组织超螺旋结构域结构的其他特性，并且可以解释位于细菌启动子上游的DNA序列之间A-tract依赖性弯曲程度缺乏保守性。
Intrinsically bent DNA sequences have been implicated in the activation of transcription by promoting juxtaposition of DNA sequences near the terminal loop of a superhelical domain. We have developed a novel topological assay for DNA looping based on λ integrative recombination to study the effects of intrinsically bent DNA sequences on the tertiary structure of negatively supercoiled DNA. Remarkably, the localization of adenosine-tract (A-tract) sequences in the terminal loop of a supercoiled plasmid is independent of the extent of intrinsic bending. The results suggest that A-tract-containing sequences have other properties that organize the structure of superhelical domains apart from intrinsic bending and may explain the lack of conservation in the degree of A-tract-dependent bending among DNA sequences located upstream of bacterial promoters.