[Inhibition of colicin synthesis during integration of transposons into the ColE1 plasmid in Escherichia coli].

Insertions of transposons into ColE1 plasmid have been shown to influence the plasmid-specified colicin synthesis. The quantity of colicin produced by a single bacterium being unchanged, a portion of colicin-producing cells in the population of those containing insertion mutants was 10(1)-10(4)-fold lower than in the case of ColE1. The effect of transposon was only observed in cis. Insertions were located in different sites of plasmid in both orientations. No secondary DNA rearrangements were formed in regions adjacent to the points of insertions. On the basis of data obtained. It is concluded that the phenomenon can be connected with neither of known types of mutations induced by transposons. A possibility of existence of a new type of such mutations is discussed.