XcmI as a universal restriction enzyme for single-stranded DNA.

Single-stranded DNA can be cleaved into defined fragments at any predetermined site by interaction with a specially designed oligodeoxyribonucleotide (oligo) adaptor and the class-IIN restriction endonuclease, XcmI. The oligo adaptor has the structure [sequence: see text]. Upon hybridization to the target DNA through the central 9-nucleotide region and with the addition of XcmI, the template DNA is specifically cleaved to near completion. Hairpin structures on the template close to the hybridization site reduce the efficacy of cleavage.