Plot showing the distribution of basic and acidic residues in the hypervariable regions of various proteins of the Ras and Rho families. The hypervariable regions of these proteins are characterized by having a high degree of positive charge or further lipid modification sites to aid membrane interaction and association. Sequences are aligned on the terminal isoprenylated cysteine residue (dark grey), residues of the hypervariable regions are coloured by their properties: basic residues are in blue, acidic in red, sites of potential additional lipidation in dark grey and all others are white. Light grey denotes residues of the G-domain. There is a large variation in both sequence and charge distribution within these HVRs, even when comparing highly similar isoforms of a protein e.g. RalA and RalB. This hypervariability led to the conclusion that these disordered regions, once neglected, must be crucial for the complex signalling of these proteins.