We present results of computer simulations of the Azoarcus group I intron in 50 mM KCl, with varying Mg2+ concentration. We show that the monovalent cations substantially stabilize the secondary structure and reduce the radius of gyration of the intron, but that elements of the tertiary structure require Mg2+ to form. At sub-millimolar Mg2+ concentration, a transient formation of individual tertiary elements is detected in the unfolded intron. The transient existence of each element is precisely correlated in time with binding of Mg2+ ions by specific RNA residues. We find that the binding sites associated with individual tertiary elements in the unfolded intron are preserved in the crystallographic structure of the folded intron. Increasing Mg2+ concentration above 1 mM leads to the stability of the entire structure, but the folding midpoints differ among different tertiary elements. Further connection to the intron function and experiments will be provided.

How does Mg<sup>2+</sup> drive tertiary folding of RNA?

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.

How does Mg2+ drive tertiary folding of RNA?

How does Mg²⁺ drive tertiary folding of RNA?