Escherichia coli factor Y sites of plasmid pBR322 can function as origins of DNA replication.

Abstract

The Escherichia coli replication factor Y, in conjunction with other genetically undefined E. coli replication factors and the gene products of the E. coli dnaB, dnaC and dnaG loci, is involved in de novo primer formation on phage .vphi.X174 (+) single-strand circular DNA template [(+) ss(c)DNA]. The participation of factor Y in this series of reactions is correlated with its .vphi.X174 (+) ss(c)-specific DNA-dependent ATPase activity. Two factor Y effector DNA segments of the plasmid pBR322 were identified in close proximity to the plasmid origin of DNA replication. Insertion of factor Y sites into the filamentous phage f1R229 (+) ss(c)DNA confers the ability to be converted to RF DNA in vitro through a rifampicin-resistant dnaB, dnaC and dnaG gene product-dependent pathway. Factor Y effector sites can apparently function as origins of DNA replication.