Replication of the Adeno-Associated Virus DNA Termini in vitro

The validity of the model proposed by Cavalier-Smith for the replication of linear, single-stranded DNA molecules was tested by using subgenomic DNA termini isolated from adeno-associated virus (AAV), a defective parvovirus. In purified DNA replication systems, the terminal hairpin structure of AAV DNA with a 3'-OH end was shown to prime the synthesis of the daughter DNA strand, which was covalently linked to the parental strand. This resulted in the synthesis of a duplex DNA structure with a terminal hairpin. The availability of such a hairpin structure should facilitate the isolation and characterization of the pivotal enzyme, the putative nickase, for the replication of AAV DNA.