Visualization of Protein Ligand Graphs (VPLG) uses a graph-based model to describe the structure of proteins on the super-secondary structure level. A protein-ligand graph is computed from the atomic coordinates in a PDB file and the secondary structure assignments of the DSSP algorithm. In this graph, vertices represent secondary structure elements (SSEs, usually alpha helices and beta strands) or ligand molecules, while the edges model contacts and relative orientations between them. The graphs can be visualized, written to a database, and saved in a text-based file format.
