1EXT

EXTRACELLULAR DOMAIN OF THE 55KDA TUMOR NECROSIS FACTOR RECEPTOR. CRYSTALLIZED AT PH3.7 IN P 21 21 21.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.203 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structures of the extracellular domain of the type I tumor necrosis factor receptor.

Naismith, J.H.Devine, T.Q.Kohno, T.Sprang, S.R.

(1996) Structure 4: 1251-1262

  • DOI: https://doi.org/10.1016/s0969-2126(96)00134-7
  • Primary Citation of Related Structures:  
    1EXT

  • PubMed Abstract: 

    Tumor necrosis factor (TNF) is a powerful cytokine that is involved in immune and pro-inflammatory responses. Two TNF receptors that belong to the cysteine-rich low affinity nerve growth factor receptor family (TNF-R1 and TNF-R2) are the sole mediators of TNF signalling. Signalling is thought to occur when a trimer of TNF binds to the extracellular domains of two or three receptor molecules, which permits aggregation and activation of the cytoplasmic domains. The complex is then internalized within an endocytic vesicle, whereupon it dissociates at low pH. Structure of the soluble extracellular domain of the receptor (sTNF-R1) both in the unliganded and TNF-bound state have previously been determined. In both instances, the fourth subdomain of the receptor was found to be partly disordered. In the unliganded state at pH 7.5, the extracellular domain forms two distinct types of dimer, parallel and antiparallel; the antiparallel dimer occludes the TNF-binding. We have determined the structure of sTNF-R1 in two crystal forms in high salt at pH 3.7. The orthorhombic crystals diffract to 1.85 ånd the entire polypeptide is well ordered. In contrast, the C-terminal 32 residues are disordered in the hexagonal crystals. In the orthorhombic form, these residues exhibit a topology and disulphide connectivity that differs from the other three cysteine-rich domains in the molecule. In both forms, the interface is considerably more extensive than that used in complex formation with LTalpha. This 'low pH' dimer is different from both of the dimers observed in crystals grown at pH 7.5. The occurrence of the antiparallel dimers in both low pH crystal forms suggest that they are not an artefact of crystal packing. Such dimers may form in the low pH environment of the endosome. Because the dimer contact surface occludes the TNF-binding site, formation of this dimer would dissociate the TNF-receptor complex within the endosome. Three of the four cysteine-rich domains of TNF-R1 are constructed from two distinct structural modules, termed A1 and B2. The fourth subdomain comprises an A1 module followed by an unusual C2 module. Although the orientation of these modules with respect to each other is sensitive to crystal packing, ligand binding, pH and ionic strength, the modules are structurally well conserved between and within the known sTNF-R1 structures.


  • Organizational Affiliation

    Centre for Biomolecular Sciences, Purdie Building, The University, St. Andrews, KY16 9ST, Scotland, UK. naismith@st-andrews.ac.uk


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
TUMOR NECROSIS FACTOR RECEPTOR
A, B
162Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P19438 (Homo sapiens)
Explore P19438 
Go to UniProtKB:  P19438
PHAROS:  P19438
GTEx:  ENSG00000067182 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP19438
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.203 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.81α = 90
b = 83.06β = 90
c = 67.9γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1997-01-11
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-09
    Changes: Database references, Derived calculations, Refinement description