Shown is side-by-side stereographic ribbon representation of the crystal structure of ILY (2). Shown are locations of the D3 transmembrane β-hairpins (blue), β-strands β1, β4, and β5 (magenta, green, and orange, respectively). Also shown are the D4 L1, L2, and L3 loop residues Leu-518, Ala-428, and Ala-464 (respectively) (red), the undecapeptide loop (yellow), and residue Ala-486 in the undecapeptide (cyan). D1–D4, domains 1–4. The ribbon structures were generated using Virtual Molecular Display (31).