Properties of Replicating SV40 DNA Molecules and Mapping Unpaired Regions in SV40 DNA I

Last year at this meeting Salzman et al. (1974) reviewed certain aspects of SV40 DNA replication. In brief, it was shown that (a) initiation of synthesis occurs at a specific site, (b) replication is bidirec-tional, (c) chain growth occurs by a discontinuous mechanism with the possible involvement of two polymerases, one required for synthesis of 4S frag-ments and the second involved in filling the gaps be-tween these fragments and the growing chains, and (d) a mechanism ust exist which allows for nick-ing and sealing of parental strands to permit DNA replication and yet preserves a covalently closed structure in the template strands of the replicating molecules. In this paper, findings are reported which describ