This entry consists of mammal and viral interferon gamma receptor proteins. Molecular interactions among cytokines and cytokine receptors in eukaryotes form the basis of many cell-signalling pathways relevant to immune function. Human interferon-gamma (IFN-gamma) signals through a multimeric receptor complex consisting of two different but structurally related transmembrane chains: the high-affinity receptor-binding subunit (IFN-gammaRalpha) and a species specific accessory factor (AF-1 or IFN-gammaRbeta) [1]. The vaccinia viral interferon gamma receptor has been shown to be secreted from infected cells during early infection [2]. The structure has been halved such that the N-terminus of this family is now represented by Tissue_fac Pfam:PF01108 (which represents the D1 domain), and this domain represents the D2 domain [1,3], both of which adopt an Ig-like fold. This domain is mediates receptor-receptor contacts [3].

1: Observation of an unexpected third receptor molecule in the crystal structure of human interferon-gamma receptor complex. Thiel DJ, le Du MH, Walter RL, D'Arcy A, Chene C, Fountoulakis M, Garotta G, Winkler FK, Ealick SE; Structure Fold Des 2000;8:927-936. PMID:10986460

2: The vaccinia virus soluble interferon-gamma receptor is a homodimer. Alcami A, Smith GL; J Gen Virol. 2002;83:545-549. PMID:11842249

3: Structure of the IFNgamma receptor complex guides design of biased agonists. Mendoza JL, Escalante NK, Jude KM, Sotolongo Bellon J, Su L, Horton TM, Tsutsumi N, Berardinelli SJ, Haltiwanger RS, Piehler J, Engleman EG, Garcia KC; Nature. 2019;567:56-60. PMID:30814731