PECULIARITIES OF GENE-EXPRESSION OF THE ECORII MODIFICATION-RESTRICTION SYSTEM

The restriction-modification genes of the EcoRII system have been clon ed into plasmids under control of phage-specific promoters T7 and SP6. The transcription was induced by cell infection with the recombinant M13 phages with the corresponding genes of phage RNA-polymerases under control of the p(lac)-promoter in the presence of IPTG. The induction yields significant amounts of EcoRII DNA-methylase for both phage-spe cific promoters. In both cases no increase in EcoRII endonuclease expr ession could be achieved. We hypothesize that the expression of the en donuclease gene is regulated on the translational level.