The mechanism of SV40 DNA replication is certainly not completely understood. The proteins that are necessary for replication have been known for quite some time, but how they work together to form a nanomachine capable of faithfully replicating the virus DNA is only partially understood. Some of the proteins involved have been crystallized and their 3D structures determined, and several EM reconstructions of SV40 T antigen have been generated. In addition, there is a fair amount of biochemical data that pinpoints the sites of interaction between various proteins. With this information, various models were assembled that show how the SV40 DNA replication nanomachine could be structured in three dimensional space. This process was aided by the use of a 3D docking program as well as fitting of structures. The advantage of the availability of these models is that they are experimentally testable and they provide an insight into how the replication machine could work. Another advantage is that it is possible to quickly compare newly published structures to the models in order to come up with improved models.
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