1xed
Crystal Structure of a Ligand-Binding Domain of the Human Polymeric Ig Receptor, pIgR
|
OverviewOverview
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.
DiseaseDisease
Known disease associated with this structure: IgA nephropathy, susceptibility to OMIM:[173880]
About this StructureAbout this Structure
1XED is a Single protein structure of sequence from Homo sapiens with MG as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of a polymeric immunoglobulin binding fragment of the human polymeric immunoglobulin receptor., Hamburger AE, West AP Jr, Bjorkman PJ, Structure. 2004 Nov;12(11):1925-35. PMID:15530357
Page seeded by OCA on Mon Nov 12 20:04:23 2007