Five strains of Enterobacteriaceae family have been revealed that have restriction-modification systems of type II, isoschizomers of SsoII. The genes coding for the restriction endonucleases and DNA methyltransferases are located on plasmids of two types. These plasmids differ in size, capacity for mobilization by conjugative plasmids, and structure of locus cer. Recombinant two-plasmid strains were obtained containing plasmids with genes for Ecl18kI and EcoRII restriction endonucleases in the presence of DNA methyltransferase Ecl18kI. The stability of the two-plasmid system with the ecoRIIR and ecl18kIM genes implies similar mechanisms of concerted regulation of gene expression in the restriction-modification systems Ecl18kI and EcoRII. Genes for Ecl18kI and SsoII restriction-modification systems have essentially the same sequence.
|Original language||English (US)|
|Number of pages||7|
|State||Published - Sep 1 1997|
All Science Journal Classification (ASJC) codes
- Structural Biology