Modification of Nucleoside Heterocycles to Probe and Expand Nucleic Acid Structure and Function

Recent progress in molecular biology and genetics has invigorated interest in modified nucleic acids both for fundamental studies and for practical applications. Herein, recent advances in design of modified non-Watson-Crick base pairs are highlighted. Examples of altered hydrogen-bonding patterns, size-expanded bases,and base pairing dependent on metal chelation and hydrophobic interactions are discussed.