[Effect of plasmid F'Col+trp+ on the transfer of plasmid RP4]

Interaction of conjugative plasmids F'colV colB trp and PR4 in Escherichia coli host was studied during the transfer of the plasmids from cell to cell. The plasmid F'colV colB trp is found to stimulate the transfer of RP4 from the diplasmid strain. This seems to be due to stabilization of the conjugating pairs which require normal pili coded by the plasmid F'colV colB trp.