Amino Acid Alignment of β-keratins showing the 32aa Filament Segment of Feathers: Alignment of the two most diverged feather β-keratins from each chromosome of G. gallus and T. guttata. Annotation of the sequences includes the three letter abbreviation of the species, the chromosome number, type of β-keratin, and the number indicating position in the 5' to 3' direction on each chromosome. The 31 amino acids in the box comprise those described by Fraser and Parry  as the 32-residue segment constituting the filament framework of feather β-keratins. Both the G. gallus and T. guttata β-keratins possess a deletion in position 3 of the 32-residue segment.
Greenwold and Sawyer BMC Evolutionary Biology 2010 10:148 doi:10.1186/1471-2148-10-148