Sequence alignment of Hint and Asw. Secondary structural elements are from the crystal structure of rabbit Hint . The primary sequences of rabbit  and chicken  Hint are aligned with chicken  and quail  Asw. Green denotes identity among all sequences. Blue denotes identity between Hint sequences at residues not identical in Asw. Pink denotes identity between Asw sequences at residues not identical in Hint. Sixteen residues involved in AMP interactions, including 14 identified from Hint-nucleotide co-crystal structures  plus His110 and Trp123, are boxed. Note that 15 of 16 nucleotide-interacting (boxed) residues are chromosomally dimorphic (pink/blue) and that the dimer interface, which is located primarily in helix α2 and strand β4, is highly conserved.