Synthesis and Applications of Oligoribonucleotides Containing N4-Methylcytidine

The modified nucleoside N 4-methylcytidine was incorporated in place of individual C residues in synthetic TAR and RRE RNA duplexes representing the binding sites for the HIV-1 tat and rev proteins respectively. In no case was cognate protein binding disrupted showing that the exocyclic amino groups of C residues are not sites of protein recognition.