Table 4. Codons corresponding to FCBS-enriched sequence motifs.

Codon	Amino acid	FCBS-enriched sequences	AA category
GAC	Asp / D	one of two codons	acidic
UAU	Tyr / Y	both codons	aromatic
UAC	Tyr / Y	both codons	aromatic
TGG	Trp / W	only codon	aromatic
GGA	Gly / G	one of four codons	small

Notes:

Phe/F is the only aromatic amino acid not encoded by FCBS-enriched sequence motifs. Phe/F codons are UUU and UUC.

TGG (Trp/W) is the least abundant of all vertebrate codons. TAT and TAC (Tyr/Y) are also low-abundance codons.