Direct visualization of the EcoRII-DNA triple synaptic complex by atomic force microscopy
Direct visualization of the EcoRII-DNA triple synaptic complex by atomic force microscopy
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DOI：
10.1021/bi701123u
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发表时间：
2007-10-02
期刊：
影响因子：
2.9
通讯作者：
Lyubchenko, Yuri L.
中科院分区：
文献类型：
--
作者：
Shlyakhtenko, Luda S.;Gilmore, Jamie;Lyubchenko, Yuri L.
由特殊蛋白质介导的遥远分离的 DNA 区域之间的相互作用导致突触蛋白质-DNA 复合物的形成。这是一种普遍存在的现象，在各种遗传过程中至关重要。虽然这种相互作用通常发生在两个位点之间，但三个特定 DNA 区域之间的相互作用已被识别，并提出了相应的模型。使用原子力显微镜测试该模型的 EcoRII 限制酶，并提供涉及三个 DNA 结合位点的突触蛋白-DNA 复合物的直接可视化和表征。该复合物在图像中显示为双环结构，长度测量证明了复合物中蛋白质的位点特异性。蛋白质体积测量表明 EcoRII 二聚体是三位点突触体的核心。鉴定并分析了其他复合物。蛋白质体积数据表明，蛋白质的二聚体形式也负责其他类型突触复合物的形成。讨论了这些结果在蛋白质-DNA 相互作用机制中的应用。
Interactions between distantly separated DNA regions mediated by specialized proteins lead to the formation of synaptic protein-DNA complexes. This is a ubiquitous phenomenon which is critical in various genetic processes. Although such interactions typically occur between two sites, interactions among three specific DNA regions have been identified, and a corresponding model has been proposed. Atomic force microscopy was used to test this model for the EcoRII restriction enzyme and provide direct visualization and characterization of synaptic protein-DNA complexes involving three DNA binding sites. The complex appeared in the images as a two-loop structure, and the length measurements proved the site specificity of the protein in the complex. The protein volume measurements showed that an EcoRII dimer is the core of the three-site synaptosome. Other complexes were identified and analyzed. The protein volume data showed that the dimeric form of the protein is responsible for the formation of other types of synaptic complexes as well. The applications of these results to the mechanisms of the protein-DNA interactions are discussed.