spacer THE STRUCTURE OF TUMOR NECROSIS FACTOR-ALPHA AT 2.6 ANGSTROMS RESOLUTION. IMPLICATIONS FOR RECEPTOR BINDING
Primary citation
Title The structure of tumor necrosis factor-alpha at 2.6 A resolution. Implications for receptor binding.
Authors Eck, M.J.search; Sprang, S.R.search
Journal J.BIOL.CHEM.search vol:264, pag:17595-17605 (1989), Identifiers: PubMed ID (2551905)search
Abstract The three-dimensional structure of tumor necrosis factor (TNF-alpha), a protein hormone secreted by macrophages, has been determined at 2.6 A resolution by x-ray crystallography. Phases were determined by multiple isomorphous replacement using data collected from five heavy atom derivatives. The multiple isomorphous replacement phases were further improved by real space symmetry averaging, exploiting the noncrystallographic 3-fold symmetry of the TNF-alpha trimer. An atomic model corresponding to the known amino acid sequence of TNF-alpha was readily built into the electron density map calculated with these improved phases. The 17,350-dalton monomer forms an elongated, antiparallel beta-pleated sheet sandwich with a "jelly-roll" topology. Three monomers associate intimately about a 3-fold axis of symmetry to form a compact bell-shaped trimer. Examination of the model and comparison to known protein structures reveals striking structural homology to several viral coat proteins, particularly satellite tobacco necrosis virus. Locations of residues conserved between TNF-alpha and lymphotoxin (TNF-beta, a related cytokine known to bind to the same receptors as TNF-alpha) suggest that lymphotoxin, like TNF-alpha, binds to the receptor as a trimer and that the general site of interaction with the receptor is at the "base" of the trimer.
MeSH terms Amino Acid Sequencesearch, Binding Sitessearch, Capsidsearch, Humanssearch, Lymphotoxin-alphasearch, Macromolecular Substancessearch, Modelssearch, Molecularsearch, Molecular Sequence Datasearch, Molecular Structuresearch, Molecular Weightsearch, Protein Conformationsearch, Receptorssearch, Cell Surfacesearch, Receptorssearch, Tumor Necrosis Factorsearch, Sequence Homologysearch, Nucleic Acidsearch, Tumor Necrosis Factor-alphasearch, X-Ray Diffractionsearch
Secondary citations
Title Crystallization of Trimeric Recombinant Human Tumor Necrosis Factor (Cachectin)
Authors Eck, M.J.search; Beutler, B.search; Kuo, G.search; Merryweather, J.P.search; Sprang, S.R.search
Journal J.BIOL.CHEM.search vol:263, pag:12816 (1988)
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