Fig. 4.
Fuzzy-logic design converges on amino acids with physicochemical properties that resemble those of the natural H-RAS. Sequence logos [68] of the natural, positive-only, and fuzzy-logic designed sequences of two structures with distinct conformations: H-RASSOS1 and H-RASRal-GDS. All designable positions exhibit two features: (i) a different sequence is compatible with each structure after positive design and (ii) the sequences of the two converge after the design to identities physicochemically similar to those observed in the natural sequence.