Results obtained from protein 1YP2.

<p>(A). The cartoon structure: the two symmetric substructures are shown in red and green; the extended irregular structure in the middle of the helix is shown in blue. (B). The profile of local codon usage bias: the decreased region in the middle of the codon sequence is shown with dashed square lines. (C). The comparison between the profile of the natural gene sequence and the averaged profile of the same codon sequence randomized by 10 times. The blue line is for natural gene sequence and the red line is for the average of the random sequences. (D). The profile of local folding free energy, and the dashed square lines shows the region with decreased local folding free energy. (F). The comparison between the natural gene sequence and the random sequences. The blue line is for natural gene sequence and the red line is for the average of the random sequences.