Figure 7.

Stability of native and permuted sequences in humans with boxplots. A and B are for alternative splice sites. C and D are for constitutive splice sites. E and F are for skipped splice sites. The permuted sequences ("_p1",white) that kept the first order nucleotide frequencies always had less stable structures than the native sequences ("_orig", black). The difference was significant but relatively small compared with the difference between different GC-number groups. However, when the dinucleotide frequencies were fixed ("_p2", grey), the permuted sequences exhibited comparable structural stability, indicating insignificant contribution from the nucleotide order.