Metals induce transient folding and activation of the twister ribozyme.

Twister is a small ribozyme present in almost all kingdoms of life that rapidly self-cleaves in variety of divalent metal ions. We used activity assays, bulk FRET and single-molecule FRET (smFRET) to understand how different metal ions promote folding and self-cleavage of the Oryza sativa twister ribozyme. Although most ribozymes require additional Mg for catalysis, twister inverts this expectation, requiring 20-30 times less Mg to self-cleave than to fold.