Site-specific covalent modification of RNA guided by functionality-transfer oligodeoxynucleotides.

Efficient methods for the covalent modification of large RNA molecules should find significance utility as innovative biological tools as well as therapeutic methods. In this study, the development of a general method for site-specific RNA modification guided by the functional ODN template has been investigated. The ODN probe containing 6-thioguanosine was modified by the methylenediketone derivative to form the S-functionalized ODN. Site-specific and cytosine-selective RNA modifications were achieved by the functionality-transfer reaction from the sulfur atom of the functionalized probe to the amino group of the cytosine base of the target strand. It was shown that the base and site selectivity were due to the close proximity of the reactants in the DNA-RNA duplexes.