Opposite effects of high-valent cations on the elasticities of DNA and RNA duplexes revealed by magnetic tweezers

We report that multivalent cations decrease the persistence length, stretching modulus, helical density and size of plectonemes formed under torque of DNA but increase those of RNA. Multivalent cations affect these physical parameters synchronously, which may imply they are intrinsically correlated. The helical densities of DNA and RNA duplexes are significantly affected by multivalent cations, which may affect the structures and the interactions with proteins in vivo.

Read more at Physical Review Letters: 
https://journals.aps.org/prl/accepted/f307eY30R971d878009c28f8568064cdd887f4e57