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PDBsum entry 4nfc

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protein Protein-protein interface(s) links
Immune system PDB id
4nfc

 

 

 

 

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Contents
Protein chains
120 a.a.
Waters ×41
PDB id:
4nfc
Name: Immune system
Title: Structure of paired immunoglobulin-like type 2 receptor (pilr )
Structure: Paired immunoglobulin-like type 2 receptor beta. Chain: a, b. Fragment: unp residues 32-150. Synonym: activating receptor pilr-beta, cell surface receptor fdfact. Engineered: yes
Source: Homo sapiens. Human. Organism_taxid: 9606. Gene: fdfact, pilr, pilrb, pp1551. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.20Å     R-factor:   0.221     R-free:   0.258
Authors: Q.Lu,G.Lu,J.Qi,Y.Li,Y.Zhang,H.Wang,Z.Fan,J.Yan,G.F.Gao
Key ref: Q.Lu et al. (2014). PILRα and PILRβ have a siglec fold and provide the basis of binding to sialic acid. Proc Natl Acad Sci U S A, 111, 8221-8226. PubMed id: 24843130 DOI: 10.1073/pnas.1320716111
Date:
31-Oct-13     Release date:   28-May-14    
PROCHECK
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 Headers
 References

Protein chains
Pfam   ArchSchema ?
Q9UKJ0  (PILRB_HUMAN) -  Paired immunoglobulin-like type 2 receptor beta from Homo sapiens
Seq:
Struc:
227 a.a.
120 a.a.*
Key:    PfamA domain  Secondary structure  CATH domain
* PDB and UniProt seqs differ at 1 residue position (black cross)

 

 
DOI no: 10.1073/pnas.1320716111 Proc Natl Acad Sci U S A 111:8221-8226 (2014)
PubMed id: 24843130  
 
 
PILRα and PILRβ have a siglec fold and provide the basis of binding to sialic acid.
Q.Lu, G.Lu, J.Qi, H.Wang, Y.Xuan, Q.Wang, Y.Li, Y.Zhang, C.Zheng, Z.Fan, J.Yan, G.F.Gao.
 
  ABSTRACT  
 
Paired immunoglobulin-like type 2 receptor α (PILRα) and β (PILRβ) belong to the PILR family and are related to innate immune regulation in various species. Despite their high sequence identity, PILRα and PILRβ are shown to have variant sialic acid (SA) binding avidities. To explore the molecular basis of this interaction, we solved the crystal structures of PILRα and PILRβ at resolutions of 1.6 Å and 2.2 Å, respectively. Both molecules adopt a typical siglec fold but use a hydrophobic bond to substitute the siglec-specific disulfide linkage for protein stabilization. We further used HSV-1 glycoprotein B (gB) as a representative molecule to study the PILR-SA interaction. Deploying site-directed mutagenesis, we demonstrated that three residues (Y2, R95, and W108) presented on the surface of PILRα form the SA binding site equivalent to those in siglecs but are arranged in a unique linear mode. PILRβ differs from PILRα in one of these three residues (L108), explaining its inability to engage gB. Mutation of L108 to tryptophan in PILRβ restored the gB-binding capacity. We further solved the structure of this PILRβ mutant complexed with SA, which reveals the atomic details mediating PILR/SA recognition. In comparison with the free PILR structures, amino acid Y2 oriented variantly in the complex structure, thereby disrupting the linear arrangement of PILR residues Y2, R95, and W108. In conclusion, our study provides significant implications for the PILR-SA interaction and paves the way for understanding PILR-related ligand binding.
 

 

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