[Determination of the minimal length DNA homologous region required for plasmid integration into the Bacillus subtilis chromosome via homologous recombination]. / Opredelenie minimal'noi dliny gomologichnogo uchastka DNK, neobkhodimoi dlia integratsii plazmid v khromosomu Bacillus subtilis posredstvom gomologichnoi rekombinatsii.

With a view to determine a minimal sequence length of homology necessary for RecE-dependent homologous recombination in Bacillus subtilis cells, we developed a system, based on interaction between plasmid replicon and bacterial chromosome. Recombination frequencies were measured between ts plasmid pE194 derivatives carrying chromosomal beta-glucuronidase gene (bglS) fragments of various length, and a bacterial chromosome. The homologous recombination events resulted in bglS gene disruption. Approx. 70 bp of homology were found to be necessary for detectable homologous recombination. Homologous recombination was not detected when homology was equal 25 bp. These data indicate that homology requirement for recombination in B. subtilis differs from that in Escherichia coli.

[The role of DNA-gyrase from Bacillus subtilis during intermolecular irregular recombination]. / Issledovanie roli DNK-girazy Bacillus subtilis v protsesse mezhmolekuliarnoi nezakonnoi rekombinatsii.

The location of oxolinis acid-induced gyrase cleavage sites on pBR322 and pUB110 plasmid DNA in Bacillus subtilis cells has been studied and established. The treated Bacillus subtilis protoplasts were used in the study. Coordinates of the gyrase cleavage sites were compared to the location of the illegitimate recombination sites precisely mapped on the plasmid genomes. The obtained data indicate involvement of the DNA gyrase in formation of a fraction of recombinants in Bacillus subtilis.