[Structural-functional organization of the par region of the ColN plasmid].

In the 679 b.p. SalI-KpnI-fragment of the small colicinogenic plasmid Co1N, the par-region has been localized, functioning at the expense of resolution of plasmid DNA multimer forms. It has been shown that the replication process of the monomeric form of the recombinant plasmid containing the Co1N par-region do not result in formation of a considerable number of multimers. Gene xer A product is necessary for the functioning of the multimer resolution mechanism of Co1N as well as Co1E1. Nucleotide sequence analysis of the Co1N par-region revealed the presence of essential homology with the par-locus of plasmid Co1E1. Results obtained in this work and data from literature indicate that par-regions of the Co1E1-type plasmids possess considerable homology, function according to a similar mechanism and represent the universal stability module of multicopy colicinogenic plasmids.