Abstract
The functional relationship between bacteriophage φX174 and SI3 gene products was investigated using an in vitro DNA synthesis system in two stages: (a), replication of the closed circular duplex form DNA (RF to RF) and (b) synthesis of single-stranded DNA from RF and formation of the intermediate 50S complex in phage morphogenesis (RF to 50S complex). Partially purified gene A products of φX174 and S13 were able to function reciprocally in the stage from RF to RF replication. In the stage of RF to 50S complex, extracts from Escherichia coli infected with φX174 catalyzed the formation of 50S complex from S13 RF DNA. Extracts from E. coli infected with SI3 also had the ability to catalyze the formation of 50S complex from φX174 RF DNA. Thus, all gene products required for DNA replication and phage morphogenesis were found to function reciprocally between φX174 and S13.
