PAN domain. The PAN domain contains a conserved core of three disulphide bridges. In some members of the family there is an additional fourth disulphide bridge the links the N and C termini of the domain. The domain is found in diverse proteins, in some they mediate protein-protein interactions, in others they mediate protein-carbohydrate interactions.
divergent subfamily of APPLE domains. Apple-like domains present in Plasminogen, C. elegans hypothetical ORFs and the extracellular portion of plant receptor-like protein kinases. Predicted to possess protein- and/or carbohydrate-binding functions.
Fringe-like. The drosophila protein fringe (FNG) is a glucosaminyltransferase that controls the response of the Notch receptor to specific ligands. FNG is localized to the Golgi apparatus (not secreted as previously thought). Modification of Notch occurs through glycosylation by FNG. The xenopus homolog, lunatic fringe, has been implicated in a variety of functions.
Subfamily of PAN/APPLE-like domains; present in plasma prekallikrein/coagulation factor XI, microneme antigen proteins, and a few prokaryotic proteins. PAN/APPLE domains fulfill diverse biological functions by mediating protein-protein or protein-carbohydrate interactions.