Protein-facilitated RNA folding.

In the absence of protein collaborators, both simple and complex RNAs often misfold or are unfolded. Biologically important RNAs solve their folding problem, in part, using the assistance of chaperone and cofactor proteins. Recent work emphasizes several rules for RNA-protein complexes: formation involves induced fit; many large RNAs fold slowly; and ribonucleoprotein assembly requires multiple steps. Finally, protein binding can introduce thermodynamic side effects.