SEQUENCE SELECTIVE DOUBLE-STRAND DNA CLEAVAGE BY PEPTIDE NUCLEIC-ACID(PNA) TARGETING USING NUCLEASE S1

A novel method for sequence specific double strand DNA cleavage using PNA (peptide nucleic acid) targeting is described. Nuclease Sl digesti on of double stranded DNA gives rise to double strand cleavage at an o ccupied PNA strand displacement binding site, and under optimized cond itions complete cleavage can be obtained. The efficiency of this cleav age is more than 1 0 fold enhanced when a tandem PNA site is targeted, and additionally enhanced if this site is in trans rather than in cis orientation. Thus in effect, the PNA targeting makes the single stran d specific nuclease Sl behave like a pseudo restriction endonuclease.