METHODS FOR CLEAVING SINGLE-STRANDED AND DOUBLE-STRANDED DNA SUBSTRATES WITH NUCLEOTIDE INTEGRASE

摘要

Methods, employing a nucleotide integrase, for cleaving single-stranded RNA substrates, single-stranded DNA substrates, and double-stranded DNA substrates at specific sites and for inserting a nucleic acid molecule into the cleaved substrate are provided. One method uses a nucleotide integrase to cleave one strand of a double-stranded DNA substrate. The method comprises the steps of: providing an isolated nucleotide integrase comprising a group II intron RNA having two hybridizing sequences for hybridizing with two intron RNA binding sequences on the top strand of the DNA substrate, and a group II-intron encoded protein which binds to a first sequence element of the substrate; and reacting the nucleotide integrase with the double-stranded DNA substrate to permit the nucleotide integrase to cleave the top strand of the DNA substrate and to insert the group II intron RNA into the cleavage site. The method of cleaving both strands of a double-stranded DNA substrate comprises the steps of: providing a nucleotide integrase comprising a group II intron RNA having two hybridizing sequences for hybridizing with two intron RNA binding sequences on one strand of the substrate, and a group II-intron encoded protein that interacts with a first sequence element and a second sequence element in the recognition site of the substrate; and reacting the nucleotide integrase with the double-stranded DNA substrate such that the nucleotide integrase cleaves both strands of the DNA substrate and inserts the group II intron RNA into the cleavage site of the one strand. The method for cleaving a single-stranded nucleic acid substrate comprises the steps of: providing a nucleotide integrase having two hybridizing sequences for hybridizing with two intron RNA-binding sequences on the single-stranded substrate, and a group II-intron encoded protein; and reacting the nucleotide integrase with the single stranded nucleic acid substrate to allow the nucleotide integrase to cleave the substrate and to attach the group II intron RNA molecule thereto.