Fig. 7.

Physical structure, circularization, and packaging mechanism of a phage with exact direct terminal repeats (DTR) at each end. a The DNA inside the phage virion before infection has the same sequence at both ends. These ends are identical in each virion. b After infection, the ends undergo homologous recombination to form a circular DNA molecule. c A linear concatemer is generated via rolling circle replication. The repeated ends are duplicated while the DNA is being packaged. Each virion has identical repeats at each end