Members of this family adopt a secondary structure consisting of seven beta-strands arranged in an immunoglobulin-like beta-sandwich, in a Greek-key topology. They are required for binding to interferon-alpha [1].

1: The human type I interferon receptor: NMR structure reveals the molecular basis of ligand binding. Chill JH, Quadt SR, Levy R, Schreiber G, Anglister J; Structure. 2003;11:791-802. PMID:12842042