Folding energy of human tRNAs. Folding energies were determined for 359 different sequences and the values were sorted by amino acids and their increasing Free folding energy (FFE) values. The intact (total, TFE), randomized (RFE), and free (FFE) folding energies are plotted. FFE = TFE-RFE. Free energy estimates were determined using the Mfold and DINAMelt Web Servers [35, 56–58].