Abstract: | Priming of phage phi X174 DNA synthesis is effected simply by dnaB protein and primase when the DNA is not coated by single-strand binding protein (SSB). The five prepriming proteins (n,n',n',i, and dnaC protein) required for priming a SSB-coated phi X174 DNA circle are dispensable. The dnaB protein-primase priming system is also active on uncoated phage G4 and M13 DNAs and on poly(dT). Multiple RNA primers, 10--60 nucleotides long, are transcribed with patterns distinctive for each DNA template. Formation of a stable dnaB protein.DNA complex in the presence of primase and ATP supports the hypothesis that dnaB protein provides a mobile replication promoter signal for primase. |