Figure 3. Amino acid abundance of FG Nups and DisProt proteins.

Amino acids are sorted according to their disorder-promoting property, with Tryptophan as the most order-promoting amino acid and Proline as the most disorder-promoting one⁴⁴. Both groups show low abundance of hydrophobic residues (Ile, Leu, Val, Trp, Tyr, Phe) compared to structured proteins. However, FG Nups have a lower content (number density) of hydrophobic residues compared to those in DisProt proteins, except for Phenylalanine. Furthermore, FG Nups demonstrate higher abundance of polar residues and lower abundance of charged residues compared to DisProt proteins. Abundance is defined as the number of residue normalized by the number of residues in the entire database.