5W38

1.80A resolution structure of human IgG3 Fc (N392K)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.183 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural characterization of the Man5 glycoform of human IgG3 Fc.

Shah, I.S.Lovell, S.Mehzabeen, N.Battaile, K.P.Tolbert, T.J.

(2017) Mol. Immunol. 92: 28-37

  • DOI: 10.1016/j.molimm.2017.10.001

  • PubMed Abstract: 
  • Immunoglobulin G (IgG) consists of four subclasses in humans: IgG1, IgG2, IgG3 and IgG4, which are highly conserved but have unique differences that result in subclass-specific effector functions. Though IgG1 is the most extensively studied IgG subcl ...

    Immunoglobulin G (IgG) consists of four subclasses in humans: IgG1, IgG2, IgG3 and IgG4, which are highly conserved but have unique differences that result in subclass-specific effector functions. Though IgG1 is the most extensively studied IgG subclass, study of other subclasses is important to understand overall immune function and for development of new therapeutics. When compared to IgG1, IgG3 exhibits a similar binding profile to Fcγ receptors and stronger activation of complement. All IgG subclasses are glycosylated at N297, which is required for Fcγ receptor and C1q complement binding as well as maintaining optimal Fc conformation. We have determined the crystal structure of homogenously glycosylated human IgG3 Fc with a GlcNAc2Man5 (Man5) high mannose glycoform at 1.8Å resolution and compared its structural features with published structures from the other IgG subclasses. Although the overall structure of IgG3 Fc is similar to that of other subclasses, some structural perturbations based on sequence differences were revealed. For instance, the presence of R435 in IgG3 (and H435 in the other IgG subclasses) has been implicated to result in IgG3-specific properties related to binding to protein A, protein G and the neonatal Fc receptor (FcRn). The IgG3 Fc structure helps to explain some of these differences. Additionally, protein-glycan contacts observed in the crystal structure appear to correlate with IgG3 affinity for Fcγ receptors as shown by binding studies with IgG3 Fc glycoforms. Finally, this IgG3 Fc structure provides a template for further studies aimed at engineering the Fc for specific gain of function.


    Organizational Affiliation

    Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Immunoglobulin heavy constant gamma 3
A, B
223Homo sapiensMutation(s): 1 
Gene Names: IGHG3
Find proteins for P01860 (Homo sapiens)
Go to UniProtKB:  P01860
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
FLC
Query on FLC

Download SDF File 
Download CCD File 
A
CITRATE ANION
C6 H5 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-K
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.183 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 64.429α = 90.00
b = 60.443β = 109.24
c = 71.396γ = 90.00
Software Package:
Software NamePurpose
Aimlessdata scaling
PHENIXrefinement
XDSdata reduction
PHASERphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-10-18
    Type: Initial release
  • Version 1.1: 2017-11-01
    Type: Database references