STRUCTURE/FUNCTION OF THE SV40 TUMOR ANTIGEN

猴病毒40(SV4O)肿瘤(T)抗原在 在病毒感染体内启动和维持SV40 DNA的复制 猴子细胞。这种蛋白质，以及DNA和细胞因子 参与，作为理解真核DNA复制的模型。这个 许多不同实验室的工作提供了对这些步骤的唯一见解 参与了这一进程，但缺乏关于这一事件的许多细节。在……里面 特别是，人们对T抗原的机制知之甚少 绑定到原点并在结构上扭曲原点。同样，我们对此知之甚少 关于这种蛋白质如何在起源和复制时解开DNA 或关于分子相互作用的性质和功能 T抗原与参与DNA复制的细胞因子之间的关系。我们的 方法是在基因中进行大量单点替换突变 蛋白质中的起始点结合结构域和其他地方，并确定 这些突变对各种生化反应的影响 在DNA合成的启动和繁殖过程中放置。通过这种方式，我们 已经确定的氨基酸可能直接或间接地 参与原基结合、非特异性DNA结合、结构结合 原点扭曲、原点展开、齐聚和 体内复制DNA。通过研究WT和各种突变蛋白，我们 建议详细研究T抗原的制备机制 通过融化和解缠复制的起源，它的方式 在原点和复制分叉处展开DNA， T抗原与细胞蛋白一起促进DNA复制，而T抗原的作用 T抗原在DNA复制的后期。通过这种方式，我们希望 更好地了解病毒和细胞DNA复制的过程 发生了。

The simian virus 40 (SV4O) tumor (T) antigen plays a crucial role in initiating and maintaining the replication of SV40 DNA in virus-infected monkey cells. This protein, along with the DNA and cellular factors involved, serves as a model to understand eukaryotic DNA replication. The work of many different labs has provided sole insights into the steps involved in this process but many details of this event are lacking. In particular, little is understood about the mechanism by which T antigen binds to and structurally distorts the origin. Likewise, we know little about how this protein unwinds the DNA at the origin and at replication forks, or about the nature and function of the molecular interactions between T antigen and the cellular factors engaged in DNA replication. Our approach has been to make numerous single-point substitution mutations in the origin-binding domain and elsewhere in the protein and to determine the effects of these mutations on various biochemical reactions that take place during initiation and propagation of DNA synthesis. In this way, we have identified amino acids that are likely to directly or indirectly participate in origin binding, nonspecific DNA binding, structural distortion of the origin, origin unwinding, oligomerization, and replication of DNA in vivo. By studying WT and various mutant proteins we propose to examine, in detail, the mechanisms by which T antigen prepares the origin for replication by melting and untwisting it, the way it unwinds DNA at the origin and at replication forks, how the interaction of T antigen with cellular proteins promotes DNA replication, and the role of T antigen in later stages of DNA replication. In this way, we hope to better understand the process by which viral and cell DNA replication takes place.