Crystal structure of the hereditary haemochromatosis protein HFE complexed with transferrin receptor.
HFE is related to major histocompatibility complex (MHC) class I proteins and is mutated in the iron-overload disease hereditary haemochromatosis. HFE binds to the transferrin receptor (TfR), a receptor by which cells acquire iron-loaded transferrin. The 2.8 A crystal structure of a complex between the extracellular portions of HFE and TfR shows two HFE molecules which grasp each side of a twofold symmetric TfR dimer. On a cell membrane containing both proteins, HFE would 'lie down' parallel to the membrane, such that the HFE helices that delineate the counterpart of the MHC peptide-binding groove make extensive contacts with helices in the TfR dimerization domain. The structures of TfR alone and complexed with HFE differ in their domain arrangement and dimer interfaces, providing a mechanism for communicating binding events between TfR chains. The HFE-TfR complex suggests a binding site for transferrin on TfR and sheds light upon the function of HFE in regulating iron homeostasis.
Bennett
M J
MJ
Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Lebrón
J A
JA
Bjorkman
P J
PJ
D018360:Crystallography, X-Ray; D006680:HLA Antigens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006432:Hemochromatosis / Q000235:genetics; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D046911:Macromolecular Substances; D008565:Membrane Proteins; D008958:Models, Molecular; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D011990:Receptors, Transferrin / Q000737:chemistry* / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism
C103673:HFE protein, human; D006680:HLA Antigens; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D046911:Macromolecular Substances; D008565:Membrane Proteins; D011990:Receptors, Transferrin; D014168:Transferrin; D007501:Iron