The sequence of nucleotides (sidechains) for this puzzle is:
To see hydrogen bonds, turn on show bonds (non-protein) in view menu.
In lua, when using structure.GetAminoAcid(n) on an RNA molecule, foldit returns a 2-letter abbreviation for base n ("ra", "rc", "rg", or "ru").
Wikipedia has a page on secondary structure of RNA, with a few pictures of shapes that RNA can make:
More pics of shapes RNA can make - scroll down to the "secondary structure" section: http://www.sivabio.50webs.com/nucleicacidstructure.htm
We really need a way to straighten out the backbone when it gets twisted (wiggle twists it a LOT when we use bands to move things around). No tweak, no remix, no rebuild, no cutting - it's very hard to recover from twisting!