The fluorescent aptamer Squash extensively repurposes the adenine riboswitch fold.
Truong, L., Kooshapur, H., Dey, S.K., Li, X., Tjandra, N., Jaffrey, S.R., Ferre-D'Amare, A.R.(2022) Nat Chem Biol 18: 191-198
- PubMed: 34937911 
- DOI: 10.1038/s41589-021-00931-2
- Primary Citation of Related Structures:  
7KVT, 7KVU, 7KVV - PubMed Abstract: 
Squash is an RNA aptamer that strongly activates the fluorescence of small-molecule analogs of the fluorophore of green fluorescent protein (GFP). Unlike other fluorogenic aptamers, isolated de novo from random-sequence RNA, Squash was evolved from the bacterial adenine riboswitch to leverage its optimized in vivo folding and stability ...