Figure 6.

Visualization of a possible folding scheme. The first structure is the starting secondary structure. The second is formed in < 1.5 ms and illustrates electrostatic relaxation upon addition of Mg²⁺ ions. The third structure is the counterion collapsed state. In the fourth structure, the T+loop structure is changed when specific Mg²⁺ ions associate, leading to a state where the second ion binding occurs when the hairpins interact. Finally, the last state is the tertiary structure.