In vitro rescue of an integrated hybrid adeno-associated virus/simian virus 40 genome.
In an in vitro simian virus 40 (SV40) DNA replication assay, we have observed excision of a hybrid adeno-associated virus (AAV)/SV40 insert from a plasmid construct. The excision was dependent on the presence of the palindromic AAV terminal repeat and greatly enhanced by the addition of the SV40 T antigen to the reaction. Analysis of the excision product supports a model in which the palindromic terminal sequences of AAV form a cruciform structure (equivalent to a Holliday recombination intermediate), which is cleaved and resealed so that the excision products are linear duplex pBR322 and linear duplex AAV/SV40 insert. Both the excised linear duplex pBR322 and the excised linear duplex AAV/SV40 insert have each terminus covalently crosslinked by one copy of the palindromic region of the AAV terminal repeat region folded on itself. The excision process may be a model system for cellular homologous recombination. The process as observed was either concomitant with or subsequent to DNA replication.
Ward
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Hearst Microbiology Research Center, Department of Microbiology, Cornell University Medical College, New York, NY 10021.
Berns
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D000260:Adenoviruses, Human / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D000957:Antigens, Viral, Tumor / Q000235:genetics; D008040:Genetic Linkage; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D010957:Plasmids; D011995:Recombination, Genetic; D012091:Repetitive Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D014779:Virus Replication
D000957:Antigens, Viral, Tumor