Crystal Structure of a Ligand-Binding Domain of the Human Polymeric Ig Receptor, pIgR

Experimental Data Snapshot

  • Resolution: 1.90 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 

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Crystal Structure of a Polymeric Immunoglobulin Binding Fragment of the Human Polymeric Immunoglobulin Receptor

Hamburger, A.E.West Jr., A.P.Bjorkman, P.J.

(2004) Structure 12: 1925-1935

  • DOI: https://doi.org/10.1016/j.str.2004.09.006
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The polymeric immunoglobulin receptor (pIgR) is a type I transmembrane protein that delivers dimeric IgA (dIgA) and pentameric IgM to mucosal secretions. Here, we report the 1.9 A resolution X-ray crystal structure of the N-terminal domain of human pIgR, which binds dIgA in the absence of other pIgR domains with an equilibrium dissociation constant of 300 nM. The structure of pIgR domain 1 reveals a folding topology similar to immunoglobulin variable domains, but with differences in the counterparts of the complementarity determining regions (CDRs), including a helical turn in CDR1 and a CDR3 loop that points away from the other CDRs. The unusual CDR3 loop position prevents dimerization analogous to the pairing of antibody variable heavy and variable light domains. The pIgR domain 1 structure allows interpretation of previous mutagenesis results and structure-based comparisons between pIgR and other IgA receptors.

  • Organizational Affiliation

    Division of Biology 114-96, California Institute of Technology, Pasadena, CA 91125, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Polymeric-immunoglobulin receptor
A, B, C, D, E
A, B, C, D, E, F
117Homo sapiensMutation(s): 0 
Gene Names: PIGR
UniProt & NIH Common Fund Data Resources
Find proteins for P01833 (Homo sapiens)
Explore P01833 
Go to UniProtKB:  P01833
GTEx:  ENSG00000162896 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01833
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.90 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.183 
  • R-Value Observed: 0.183 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.996α = 90
b = 157.195β = 112.94
c = 53.86γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
DENZOdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-11-23
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance