FIGURE 1.

Order and structure in proteins. A and B, schematic of an energy landscape for an ordered protein (A) and a disordered protein (B). Red tones indicate relatively high energy conformations, and blue tones indicate low energy conformations. C, order-structure continuum. Proteins with varying degrees of order and secondary structure propensity are shown in their approximate position on an order-structure continuum. Helices are shown in red, β-strands are shown in purple, and turns and unstructured regions are shown in green. Red, purple, and blue lines are used to indicate location along helical content, β-strand content, and order axes in three dimensions. Protein Data Bank (PDB) IDs left to right are: 2k3j (71), 1bh4 (72), PED Entry 9AAA (73), 1k7b (74), PED Entry 7AAA (75), 2kac (76), 2k3g (77), and 1qjp (78). PED refers to the Protein Ensemble Database (79).