Fig. 3.

A comparison of IL-1β and HYB^β. (A) Aligned structures of HYB^β and IL-1β. The gray regions are common to both proteins. The differences are in red (IL-1β: the β-bulge) and blue (HYB^β: tight β-turn). The gray and red spheres depict the C_α atoms of the residues in the B-site. (B) Contact maps of IL-1β (422 contacts) and HYB^β (384 contacts). The map is symmetric about the diagonal, and both triangles are shown for clarity. Gray contacts are common to both proteins. The red contacts are present only in IL-1β and the blue ones only in HYB^β. The circled contacts involve the β-bulge. The x and y axes give residue numbers, and the index is of the larger protein, here, IL-1β. (C and D) How different parts of the protein fold. The Insets show the different regions into which the two proteins are partitioned. The color of the parts matches the color of the Q_parts. (C) IL-1β. The initial rise and fall of the green Q_C-term denotes the backtracking. The red Q_center shows a marked increase with a reduction in the structure of the green region. (D) HYB^β. The C-terminal region forms early and stays formed. The red region increases almost linearly with Q.