Figure 3.

(A) Relative frequencies of observed supersecondary motifs (loops) in all protein chains (blue), BPs (green), ABPs (dark yellow), OBPs (purple), and PBPs (red). (B) Cartoon images of the loops present in PBPs. Different secondary structure elements are shown in color (helices in red, strands in yellow, and coiled-coil regions in green). Each motif is identified in the first text line below by the code of its corresponding loop type(s). The PDB file from where each loop structure shown was obtained, protein chain and starting residue of the supersecondary structure are provided in the second line below each cartoon.