1H3T

Crystal structure of the human igg1 fc-fragment,glycoform (mn2f)2


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.280 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Analysis of Human Igg-Fc Glycoforms Reveals a Correlation between Glycosylation and Structural Integrity

Krapp, S.Mimura, Y.Jefferis, R.Huber, R.Sondermann, P.

(2003) J.Mol.Biol. 325: 979

  • Primary Citation of Related Structures:  1H3U, 1H3V, 1H3W, 1H3X, 1H3Y

  • PubMed Abstract: 
  • Antibodies may be viewed as adaptor molecules that provide a link between humoral and cellular defence mechanisms. Thus, when antigen-specific IgG antibodies form antigen/antibody immune complexes the effectively aggregated IgG can activate a wide ra ...

    Antibodies may be viewed as adaptor molecules that provide a link between humoral and cellular defence mechanisms. Thus, when antigen-specific IgG antibodies form antigen/antibody immune complexes the effectively aggregated IgG can activate a wide range of effector systems. Multiple effector mechanisms result from cellular activation mediated through a family of IgG-Fc receptors differentially expressed on leucocytes. It is established that glycosylation of IgG-Fc is essential for recognition and activation of these ligands. IgG antibodies predominate in human serum and most therapeutic antibodies are of the IgG class. The IgG-Fc is a homodimer of N-linked glycopeptide chains comprised of two immunoglobulin domains (Cgamma2, Cgamma3) that dimerise via inter-heavy chain disulphide bridges at the N-terminal region and non-covalent interactions between the C-terminal Cgamma3 domains. The overall shape of the IgG-Fc is similar to that of a "horseshoe" with a majority of the internal space filled by the oligosaccharide chains, only attached through asparagine residues 297.To investigate the influence of individual sugar (monosaccharide) residues of the oligosaccharide on the structure and function of IgG-Fc we have compared the structure of "wild-type" glycosylated IgG1-Fc with that of four glycoforms bearing consecutively truncated oligosaccharides. Removal of terminal N-acetylglucosamine as well as mannose sugar residues resulted in the largest conformational changes in both the oligosaccharide and in the polypeptide loop containing the N-glycosylation site. The observed conformational changes in the Cgamma2 domain affect the interface between IgG-Fc fragments and FcgammaRs. Furthermore, we observed that the removal of sugar residues permits the mutual approach of Cgamma2 domains resulting in the generation of a "closed" conformation; in contrast to the "open" conformation which was observed for the fully galactosylated IgG-Fc, which may be optimal for FcgammaR binding. These data provide a structural rationale for the previously observed modulation of effector activities reported for this series of proteins.


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Abteilung Strukturforschung, Am Klopferspitz 18a, D-82152, Martinsried, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
IG GAMMA-1 CHAIN C REGION
A, B
223Homo sapiensGene Names: IGHG1
Find proteins for P01857 (Homo sapiens)
Go to UniProtKB:  P01857
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BMA
Query on BMA

Download SDF File 
Download CCD File 
A, B
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
FUL
Query on FUL

Download SDF File 
Download CCD File 
A
BETA-L-FUCOSE
6-DEOXY-BETA-L-GALACTOSE
C6 H12 O5
SHZGCJCMOBCMKK-KGJVWPDLSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.280 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 49.572α = 90.00
b = 80.776β = 90.00
c = 139.648γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-01-23
    Type: Initial release
  • Version 1.1: 2011-10-12
    Type: Atomic model, Derived calculations, Non-polymer description, Other, Refinement description, Structure summary, Version format compliance