Ribonucleosides and RNA.

Landmark discoveries such as the autocatalytic cleavage activity of certain RNA molecules, as well as small oligoribonucletide ribozymes and later the in vitro evolution of novel bioactive oligoribonucleotides (SELEX), have created entire new fields of biochemical research. The discovery of SELEX has provided a method for producing high-affinity nucleic acid ligands with high binding specificity to important medicinal targets. Including modified nucleotides into RNA ligands derived from SELEX may yield improved RNA therapeutics. The chemistry of oligoribonucleotides in comparison to oligodeoxyribonucleotides has led to resurgent attention on the role of modified nucleotides in RNA structure and function. Such modifications are also employed to impart stability towards endonuclease degradation on oligoribonucleotides.