Replication of ϕX174 DNA by Escherichia coli polA - In Vitro

Abstract
Lysates of an Escherichia coli polA(-) strain convert single-stranded DNA from varphiX174 virus to the double-stranded replicative form with high efficiency on cellophane discs. The initiation of synthesis of the complementary strand appears to be rate limiting; once initiation occurs, the chain is propagated rapidly. Under these conditions, the unsealed replicative form accumulates and is slowly converted to the sealed form; this conversion requires the activity of the DPN-dependent DNA ligase.