Charge and biological molecules: why RNA folds and DNA condenses

Double stranded RNA resists condensation

L. Li, S. A. Pabit, S. Meisburger, L. Pollack
Phys. Rev. Lett., 106, 108101 (2011).


Much attention has focused on DNA condensation because of its fundamental biological importance. The recent discovery of new roles for RNA duplexes demands efficient packaging of dsRNA for therapeutics. Here we report measurements of short DNA and RNA duplexes in the presence of trivalent ions. Under conditions where UV spectroscopy indicates condensation of DNA duplexes into (insoluble) precipitates, RNA duplexes remain soluble. SAXS results suggest that the differing surface topologies of RNA and DNA may be crucial in generating the attractive forces that result in precipitation.

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