Thermodynamics of Cooperative DNA Recognition at a Replication Origin and Transcription Regulatory Site
Thermodynamics of Cooperative DNA Recognition at a Replication Origin and Transcription Regulatory Site
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DOI：
10.1021/bi1014908
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发表时间：
2010-12-07
期刊：
影响因子：
2.9
通讯作者：
de Prat Gay, Gonzalo
中科院分区：
文献类型：
--
作者：
Dellarole, Mariano;Sanchez, Ignacio E.;de Prat Gay, Gonzalo
结合协同性引导蛋白质-核酸复合物的形成，特别是那些受到高度调控的复合物，例如复制起点和转录位点。以人乳头瘤病毒 16 型的起源结合和转录调节蛋白 E2 的 DNA 结合域为模型，通过等温滴定量热分析，我们确定了该蛋白与其同源串联双 E2 位点结合后具有正的、熵驱动的协同性。这种协同性与 DNA 结构的变化有关，其中总体 B 构象得以维持。 HPV18 和 HPV11 的两个同源 E2 结构域表明反应和 DNA 变形的熵成分可能存在分歧。由于 DNA 结合螺旋在三个结构域中几乎相同，因此差异必定分散在这个独特的二聚体 β 桶折叠中。这与该领域之前的结果惊人地一致，该结果揭示了全局动力学和 DNA 识别之间的紧密耦合。
Binding cooperativity guides the formation of protein-nucleic acid complexes, in particular those that are highly regulated such as replication origins and transcription sites. Using the DNA binding domain of the origin binding and transcriptional regulator protein E2 from human papillomavirus type 16 as model, and through isothermal titration calorimetry analysis, we determined a positive, entropy-driven cooperativity upon binding of the protein to its cognate tandem double E2 site. This cooperativity is associated with a change in DNA structure, where the overall B conformation is maintained. Two homologous E2 domains, those of HPV18 and HPV11, showed that the enthalpic-entropic components of the reaction and DNA deformation can diverge. Because the DNA binding helix is almost identical in the three domains, the differences must lie dispersed throughout this unique dimeric beta-barrel Fold. This is in surprising agreement with previous results for this domain, which revealed a strong coupling between global dynamics and DNA recognition.