1I1A

CRYSTAL STRUCTURE OF THE NEONATAL FC RECEPTOR COMPLEXED WITH A HETERODIMERIC FC


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.222 

wwPDB Validation   3D Report Full Report


This is version 2.0 of the entry. See complete history


Literature

Crystal structure at 2.8 A of an FcRn/heterodimeric Fc complex: mechanism of pH-dependent binding.

Martin, W.L.West Jr., A.P.Gan, L.Bjorkman, P.J.

(2001) Mol Cell 7: 867-877

  • DOI: 10.1016/s1097-2765(01)00230-1
  • Primary Citation of Related Structures:  
    1I1C, 1I1A

  • PubMed Abstract: 
  • The neonatal Fc receptor (FcRn) transports immunoglobulin G (IgG) across epithelia, binding IgG in acidic vesicles (pH < or = 6.5) and releasing IgG in the blood at pH 7.4. Well-ordered FcRn/Fc crystals are prevented by the formation of "oligomeric ribbons" of FcRn dimers bridged by Fc homodimers, thus we crystallized a 1:1 complex between rat FcRn and a heterodimeric Fc containing only one FcRn binding site ...

    The neonatal Fc receptor (FcRn) transports immunoglobulin G (IgG) across epithelia, binding IgG in acidic vesicles (pH < or = 6.5) and releasing IgG in the blood at pH 7.4. Well-ordered FcRn/Fc crystals are prevented by the formation of "oligomeric ribbons" of FcRn dimers bridged by Fc homodimers, thus we crystallized a 1:1 complex between rat FcRn and a heterodimeric Fc containing only one FcRn binding site. The 2.8 A complex structure demonstrates that FcRn uses its alpha2 and beta2-microglobulin domains and carbohydrate to interact with the Fc C(gamma)2-C(gamma)3 interface. The structure reveals conformational changes in Fc and three titratable salt bridges that confer pH-dependent binding, and can be used to guide rational design of therapeutic IgGs with longer serum half-lives.


    Organizational Affiliation

    Division of Biology, California Institute of Technology, Pasadena, CA 91125, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
NEONATAL FC RECEPTOR AA269Rattus norvegicusMutation(s): 0 
Gene Names: FcgrtFcrn
UniProt
Find proteins for P13599 (Rattus norvegicus)
Explore P13599 
Go to UniProtKB:  P13599
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
BETA-2-MICROGLOBULINB99Rattus norvegicusMutation(s): 0 
Gene Names: B2m
UniProt
Find proteins for P07151 (Rattus norvegicus)
Explore P07151 
Go to UniProtKB:  P07151
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
IG GAMMA-2A CHAIN C REGIONC225Rattus norvegicusMutation(s): 0 
Gene Names: Igg-2a
UniProt
Find proteins for P20760 (Rattus norvegicus)
Explore P20760 
Go to UniProtKB:  P20760
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
IG GAMMA-2A CHAIN C REGIOND239Rattus norvegicusMutation(s): 6 
Gene Names: Igg-2a
UniProt
Find proteins for P20760 (Rattus norvegicus)
Explore P20760 
Go to UniProtKB:  P20760
Protein Feature View
Expand
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 5
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranoseE2 N-Glycosylation Oligosaccharides Interaction
Entity ID: 6
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseF6 N-Glycosylation Oligosaccharides Interaction
Entity ID: 7
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[beta-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseG8 N-Glycosylation Oligosaccharides Interaction
Entity ID: 8
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-2)-alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranoseH8 N-Glycosylation Oligosaccharides Interaction
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download Ideal Coordinates CCD File 
I [auth A], J [auth A]2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
CYS
Query on CYS

Download Ideal Coordinates CCD File 
K [auth A], L [auth A]CYSTEINE
C3 H7 N O2 S
XUJNEKJLAYXESH-REOHCLBHSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.292 
  • R-Value Work: 0.222 
  • R-Value Observed: 0.222 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.358α = 90
b = 74.213β = 90
c = 196.604γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-02-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.3: 2013-09-25
    Changes: Derived calculations
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Advisory, Atomic model, Data collection, Database references, Derived calculations, Structure summary