Physical polymerization and liquid crystallization of RNA oligomers.

Ultrashort complementary RNA oligomers, as short as six base pairs in length, are found to exhibit chiral nematic and columnar liquid crystal phases in aqueous solution, through end-to-end adhesion into physically bound, but chemically segmented, polymers. Geometrical constraints indicate that the phosphate helix is continuous along the aggregated chain. The end-to-end adhesion is due to a base-staking type interaction, whose energy and temperature dependence are determined.