Fold a riboswitch with and without its ligand

Fold a transcript twice — once freely, once with the aptamer held out of the secondary structure as a bound ligand would hold it — and report what changes at the ribosome binding site. Returns both structures, both free energies, the cost of occupying the aptamer, and whether the site becomes more or less accessible. This is the question a riboswitch design can be checked on before the bench: is the site sequestered in one state and free in the other. Returns NO activation ratio and no fold-change — see this tool's validation note for why that number is not offered. Pair with rbs_occlusion, which finds what can pair over the site in the first place.