EFFECTOR OLIGONUCLEOTIDES INCREASE EFFICI ENCY OF SITE-SPECIFIC CLEAVAGE OF TARGET DNA BY BLEOMYCIN DERIVATIVES OF TETRANUCLEOTIDE

The efficiency of site-specific interaction of target DNA with bleomyc in derivatives of short nucleotides can be significantly increased usi ng flanking effector oligonucleotides. The cleavage of a 20-mer single -stranded target DNA by a tetranucleotide containing a bleomycin A(5) residue at the 5'-end was studied in the presence of effector oligonuc leotides bearing phenazine residues at the 5'- and 3'-ends. In the pre sence of two effecters, the extent of the target DNA modification at 3 7 degrees C increased from 20 to 70%. Site-specific cleavage occurs, b y up to 90%, at a single site of the target DNA. The melting temperatu re of the complementary complex formed by the bleomycin A(5)-modified tetranucleotide and target DNA in the presence of two effecters was 45 degrees C, whereas in the absence of the effecters, below 7 degrees C .