| Virus Name | Simian Virus 40 |
| Virus Short Name | SV40 |
| Order | Unassigned |
| Virus Family | Polyomaviridae |
| Virus Subfamily | N.A. |
| Genus | Betapolyomavirus |
| Species | Simian virus 40 |
| Host | Mammals, human |
| Cell Tropism | N.A. |
| Associated Disease | N.A. |
| Mode of Transmission | N.A. |
| VIPR DB link | N.A. |
| ICTV DB link | https://talk.ictvonline.org/ictv-reports/ictv_9th_report/dsdna-viruses-2011/w/dsdna_viruses/129/polyomaviridae |
| Virus Host DB link | N.A. |
| Paper Title | Simian virus 40 DNA replication is dependent on an interaction between topoisomerase I and the C-terminal end of T antigen |
| Author's Name | Sujata Khopde and Daniel T. Simmons |
| Journal Name | Journal Of Virology |
| Pubmed ID | 18003733 |
| Abstract | Topoisomerase I (topo I) is needed for efficient initiation of simian virus 40 (SV40) DNA replication and for the formation of completed DNA molecules. Two distinct binding sites for topo I have been previously mapped to the N-terminal (residues 83 to 160) and C-terminal (residues 602 to 708) regions of T antigen. By mutational analysis, we identified a cluster of six residues on the surface of the helicase domain at the C-terminal binding site that are necessary for efficient binding to topo I in enzyme-linked immunosorbent assay and far-Western blot assays. Mutant T antigens with single substitutions of these residues were unable to participate normally in SV40 DNA replication. Some mutants were completely defective in supporting DNA replication, and replication was not enhanced in the presence of added topo I. The same mutants were the ones that were severely compromised in binding topo I. Other mutants demonstrated intermediate levels of activity in the DNA replication assay and were correspondingly only partially defective in binding topo I. Mutations of nearby residues outside this cluster had no effect on DNA replication or on the ability to bind topo I. These results strongly indicate that the association of topo I with these six residues in T antigen is essential for DNA replication. These residues are located on the back edges of the T-antigen double hexamer. We propose that topo I binds to one site on each hexamer to permit the initiation of SV40 DNA replication. |
| Used Model | Sf9 cells |
| DOI | 10.1128/JVI.01314-07 |
