Figure 3.

Ternary Plot of Secondary Structure Profiles for a Subset of PDB IDs

Each mark on the ternary plot represents the secondary structure composition of a single PDB ID in the subset of data. For illustration purposes, 400 points were randomly sampled and plotted from each group of PDB IDs with PEG 400 (black plus sign) and PEG 20000 (red cross). The plot shows 800 points of the 61,753 PDB IDs in the PEG-SSD dataset. In structures with a higher composition of helices (upper triangle, above the 60% mark for the H-ness axis on the left of the simplex), the points located in that sector are more likely to be black rather than red (associated with the low MW PEG instead of the high MW PEG). For the other dominated structures (triangle on the bottom left corner, above 60% mark on the bottom O-ness axis), the points are more likely to be red rather than black (associated with the high MW PEG instead of the low MW PEG). This gives a visual representation of the nature of the data used for modeling and underscores the model results.