In vitro conversion of S13 viral DNA in phage particles to the double-stranded DNA

The conversion of single-stranded DNA in S13 intact phage particles to the double-stranded replicative form DNA was observed in cell extracts prepared from Escherichia coli H560 (S13s, polA, endA) cells lysed with lysozyme and the non-ionic detergent, Brij 58. The DNA product, which associated with a rapidly sedimenting component, was identified as RFII-DNA with a gap by sedimentation analysis. The conversion was inhibited by N-ethylmaleimide, but not by rifampicin, nicotinamide mononucleotide or polymyxin B. The dnaB gene product was involved in the replicative system. Similar extracts prepared from a S13-resistant E. coli strain K12W6 also catalyzed this synthesis.