If you want to design puzzles based on naturally-occurring RNAs, consider searching for a sequence in one of the online secondary structure databases listed below. You may have to break pseudoknots to create your puzzle. For structures represented in dot-bracket notation, this can be done by substituting a "." for symbols other than parentheses.
|RNA STRAND||Over 4000 secondary structures from a variety of sources. Structures available in dot-bracket notation.|
|Rfam||A collection of RNA families. Secondary structures must be saved through the VARNA applet.|
|fRNAdb||A database of noncoding RNAs.|
|Subviral RNA Database||A database of subviral agents.|