A two-dimensional replica-exchange molecular dynamics method for simulating RNA folding using sparse experimental restraints.

We present a 2D replica exchange protocol incorporating secondary structure information to dramatically improve 3D RNA folding using molecular dynamics simulations. We show that incorporating base-pairing restraints into all-atom, explicit solvent simulations enables the accurate recapitulation of the global tertiary fold for 4 representative RNAs ranging in length from 24 to 68 nt. This method can potentially utilize base-pairing information from a wide variety of experimental inputs to predict complex RNA tertiary folds including pseudoknots, multi-loop junctions, and non-canonical interactions.