title: Alpha-helical coiled-coil stalks in the low-affinity receptor for IgE (Fc epsilon RII/CD23) and related C-type lectins.
abstract: The low-affinity receptor for IgE (Fc epsilon RII/CD23) is a cell surface glycoprotein that plays a role in both cellular immunity and allergic inflammation. Its extracellular IgE-binding domain bears homology to C-type animal lectins, and the protein is, therefore, classified as a member of this superfamily. We predict that this lectin-like domain is separated from the cell membrane by an extensive region of alpha-helical coiled-coil structure, based upon sequence comparisons with tropomyosin, the archetypal alpha-helical coiled-coil structure, and detection of characteristic heptad repeats. Analysis of other receptor protein sequences identified a similar structural motif in other membrane-bound members of the C-type lectin superfamily, including the asialoglycoprotein receptor, the Kupffer cell receptor, and the B-cell differentiation antigen Lyb-2 (CD72). It appears that within the C-type lectin superfamily, there is a subfamily of structurally related membrane-bound receptor proteins that contain alpha-helical coiled-coil stalks of various lengths.
authors.affiliation: Biomolecular Sciences Division, King's College London, United Kingdom.
authors.forename: A J
authors.initials: AJ
authors.lastname: Beavil
authors.forename: R L
authors.initials: RL
authors.lastname: Edmeades
authors.forename: H J
authors.initials: HJ
authors.lastname: Gould
authors.forename: B J
authors.initials: BJ
authors.lastname: Sutton
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000235:genetics; D000944:Antigens, Differentiation, B-Lymphocyte / Q000737:chemistry* / Q000235:genetics; D000950:Antigens, Ly / Q000737:chemistry; D037263:Asialoglycoprotein Receptor; D006801:Humans; D007728:Kupffer Cells; D037102:Lectins / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000737:chemistry; D051379:Mice; D008969:Molecular Sequence Data; D011487:Protein Conformation; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry*; D011961:Receptors, Fc / Q000737:chemistry*; D017455:Receptors, IgE; D011971:Receptors, Immunologic / Q000737:chemistry*; D014335:Tropomyosin / Q000737:chemistry
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000950:Antigens, Ly; D037263:Asialoglycoprotein Receptor; C064228:CD72 protein, human; C072264:Kupffer cell receptor; D037102:Lectins; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; D011961:Receptors, Fc; D017455:Receptors, IgE; D011971:Receptors, Immunologic; D014335:Tropomyosin