CLEAVING DNA WITH DNA

A DNA structure is described that can cleave single-stranded DNA oligo nucleotides in the presence of ionic copper. This ''deoxyribozyme'' ca n self-cleave or can operate as a bimolecular complex that simultaneou sly makes use of duplex and tripler interactions to bind and cleave se parate DNA substrates. Bimolecular deoxyribozyme-mediated strand sciss ion proceeds with a k(obs) of 0.2 min(-1), whereas the corresponding u ncatalyzed reaction could not be detected. The duplex and tripler reco gnition domains can be altered, making possible the targeted cleavage of single-stranded DNAs with different nucleotide sequences. Several s mall synthetic DNAs were made to function as simple ''restriction enzy mes'' for the site-specific cleavage of single-stranded DNA.