[The role of genes of the system of mismatched base correction in genetic recombination of Escherichia coli].

A genetic system was elaborated to study intramolecular recombination of bacteriophages lambda and phi 80. Practically, the ideal complementation of nucleotide sequences in recombining DNA molecules is required to obtain recombinants resulting from RecA-dependent recombination in Escherichia coli cells. a hypothesis is proposed to which the correction of mismatched bases hinders recombinant formation during recombination of fully homologous DNAs. The increased yields of hybrid molecules during interaction of the same DNA in the cells with deficient genes for correction support the hypothesis as well as independent demonstration of mutation in a gene for correction according to the effect of the increased yield of recombinants. A series of Escherichia coli cells mutants with increased formation of recombinant clones has been obtained.