[Structure-functional characteristics of pBS195 plasmids from a broad range of gram-positive and gram-negative hosts]

Abstract

The ability of plasmid pBS195 to be inherited by a broad host range including both gram-positive and gram-negative bacteria attracts special attention to its molecular genetic organization. Physical map of the plasmid has been constructed and the gene for kanamycin resistance and oriV homologous to the one of pUC19 have been localized. The determinants for kanamycin-resistance have been shown to share no homology with the genes for the I and II type phosphotransferases and type II nucleotide-transferase. The minicells of Escherichia coli x925 harboring pBS195 produce two plasmid-encoded proteins with mol. masses 26 and 34 kD found in SDS-PAGE. The plasmid determines an oxygenase activity and shares homology with a nahC gene in the EcoRI-BamHI region (0 bp-1.6 kbp). The enzyme was identified as a methylpyrocatehase possessing high activity in Escherichia coli cells and substrate specificity uncharacteristic of this type enzymes.