Strands hybridize in postreplicative adenovirus overlap recombination.

We describe a postreplicative mechanism for adenovirus overlap recombination. An adenovirus minichromosome system was used to study overlap recombination driven by adenovirus DNA replication. Crossing-over appeared to occur equally at, but not within, the borders of the overlap between partner molecules. We propose that recombination in the minichromosome system proceeds through an intermediate formed by direct hybridization of complementary sequences on displaced strands generated by adenovirus-specific DNA replication. Some, but not all, heterologous regions in the intermediate are susceptible to mismatch correction. This pathway is intrinsically nonreciprocal and differs significantly from other adenovirus recombinational mechanisms that have been described previously.