A Stable DNA Duplex Containing a Non-Hydrogen-Bonding and Non-Shape-Complementary Base Couple: Interstrand Stacking as the Stability Determining Factor

摘要

Hydrogen-bonding and stacking interactions between nucleobases are the major components of the noncovalent forces that stabilize the DNA and RNA double helix.~[1,2] The relative contribution of each factor to the stability has been a matter of debate since the discovery of the structure of the double helix. Recent reports on stable duplex formation and selective DNA-polymerase-mediated rep-lication of oligodeoxynucleotides that contain hydrophobic, non-hydrogen-bonding base pairs led to a new twist in this discussion,~[3-14] and have triggered a re-evaluation of the im-portance of aromatic stacking interactions and shape selectivity in the base-pair formation.~[15]