Figure 1

Construction of the co-occurrence matrix. Construction of the co-occurrence matrix (for the simplicity windows are of length 4, and 3 sub-matrices are generated in each direction of the general matrix). Coordinates of the general matrix (large numbers) represent the location of aminoacids in the sequences. Each aminoacid is represented by a number between 1 and 20 (ordered alphabetically), located within sub-matrices. For example, the point highlighted in red would indicate a high co-occurrence score between lysine (K) at position 1 of the sequence and tryptophan (W) at position 3 of the sequence.