5VKJ

Crystal structure of human CD22 Ig domains 1-3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.12 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.204 

wwPDB Validation 3D Report Full Report



Literature

Molecular basis of human CD22 function and therapeutic targeting.

Ereno-Orbea, J.Sicard, T.Cui, H.Mazhab-Jafari, M.T.Benlekbir, S.Guarne, A.Rubinstein, J.L.Julien, J.P.

(2017) Nat Commun 8: 764-764

  • DOI: 10.1038/s41467-017-00836-6
  • Primary Citation of Related Structures:  
    5VL3, 5VKK, 5VKJ, 5VKM

  • PubMed Abstract: 
  • CD22 maintains a baseline level of B-cell inhibition to keep humoral immunity in check. As a B-cell-restricted antigen, CD22 is targeted in therapies against dysregulated B cells that cause autoimmune diseases and blood cancers. Here we report the cr ...

    CD22 maintains a baseline level of B-cell inhibition to keep humoral immunity in check. As a B-cell-restricted antigen, CD22 is targeted in therapies against dysregulated B cells that cause autoimmune diseases and blood cancers. Here we report the crystal structure of human CD22 at 2.1 Å resolution, which reveals that specificity for α2-6 sialic acid ligands is dictated by a pre-formed β-hairpin as a unique mode of recognition across sialic acid-binding immunoglobulin-type lectins. The CD22 ectodomain adopts an extended conformation that facilitates concomitant CD22 nanocluster formation on B cells and binding to trans ligands to avert autoimmunity in mammals. We structurally delineate the CD22 site targeted by the therapeutic antibody epratuzumab at 3.1 Å resolution and determine a critical role for CD22 N-linked glycosylation in antibody engagement. Our studies provide molecular insights into mechanisms governing B-cell inhibition and valuable clues for the design of immune modulators in B-cell dysfunction.The B-cell-specific co-receptor CD22 is a therapeutic target for depleting dysregulated B cells. Here the authors structurally characterize the ectodomain of CD22 and present its crystal structure with the bound therapeutic antibody epratuzumab, which gives insights into the mechanism of inhibition of B-cell activation.


    Organizational Affiliation

    Department of Immunology, University of Toronto, Toronto, ON, Canada, M5S 1A8. jean-philippe.julien@sickkids.ca.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
B-cell receptor CD22A324Homo sapiensMutation(s): 5 
Gene Names: CD22SIGLEC2
Find proteins for P20273 (Homo sapiens)
Explore P20273 
Go to UniProtKB:  P20273
NIH Common Fund Data Resources
PHAROS  P20273
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChainsChain Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-3)-[alpha-D-mannopyranose-(1-6)]beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
B
5 N-Glycosylation Oligosaccharides Interaction
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.12 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.202 
  • R-Value Observed: 0.204 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 126.807α = 90
b = 56.569β = 110.7
c = 49.434γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XSCALEdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction
PHASERphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
CIHR, BantingCanada--

Revision History 

  • Version 1.0: 2017-10-04
    Type: Initial release
  • Version 1.1: 2017-10-25
    Changes: Database references
  • Version 1.2: 2019-11-20
    Changes: Database references
  • Version 1.3: 2019-11-27
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary