Involvement of host cell gene products in conversion of bacteriophage S13 single-stranded DNa to duplex replicative...

The single-stranded circular DNA of bacteriophage S13 was converted to the duplex replicative form DNA by soluble extracts from Escherichia coli strain H560 (polA, endA) in vitro. The maximal conversion required four deoxyribonucleoside triphosphates, Mg2+, exogenous S13 DNA and ATP, but not CTP, UTP, or GTP. The conversion was blocked by N-ethylmaleinimide but not by rifampicin. The product was identified as a gapped duplex replicative form DNA. Using extracts from some thermosensitive mutants of E. coli defective in DNA replication, we found that dnaB and dnaC gene products are involved in the conversion stage of single-stranded DNA to duplex DNA in vitro.