Mechanistic analysis of local ori melting and helicase assembly by the papillomavirus E1 protein.
Mechanistic analysis of local ori melting and helicase assembly by the papillomavirus E1 protein.
复制标题
乳头瘤病毒E1蛋白局部ori熔解和解旋酶组装的机制分析。
DOI：
10.1016/j.molcel.2011.06.026
复制
发表时间：
2011
期刊：
影响因子：
16
通讯作者：
Stenlund,Arne
中科院分区：
文献类型：
--
作者：
Schuck,Stephen;Stenlund,Arne
制备用于复制的DNA模板需要打开双链体以暴露单链（ss）DNA。复制性DNA解旋酶需要局部解链的DNA来启动解旋。在真核复制子中如何产生局部解链尚不清楚，但来自少数真核病毒的起始蛋白可以执行此功能。在这里，我们剖析了乳头瘤病毒E1蛋白进行的局部熔化过程。我们从动力学角度描述了解链过程，并鉴定了E1解旋酶和ori中阻止局部解链过程的突变。我们发现，这些突变体的一个子集有特定的缺陷，熔化的中心的ori含有E1的结合位点，并证明这些突变体未能解开的ori DNA。这种对E1如何产生局部解链的理解暗示了其他复制子中局部解链的可能机制。
Preparation of DNA templates for replication requires opening of the duplex to expose single-stranded (ss) DNA. The locally melted DNA is required for replicative DNA helicases to initiate unwinding. How local melting is generated in eukaryotic replicons is unknown, but initiator proteins from a handful of eukaryotic viruses can perform this function. Here we dissect the local melting process carried out by the papillomavirus E1 protein. We characterize the melting process kinetically and identify mutations in the E1 helicase and in the ori that arrest the local melting process. We show that a subset of these mutants have specific defects for melting of the center of the ori containing the binding sites for E1 and demonstrate that these mutants fail to untwist the ori DNA. This understanding of how E1 generates local melting suggests possible mechanisms for local melting in other replicons.