Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 10.79 kDa 
• Atom Count: 787 
• Residue Count: 96 
• Unique protein chains: 1

3Q2C

Binding properties to HLA class I molecules and the structure of the leukocyte Ig-like receptor A3 (LILRA3/ILT6/LIR4/CD85e)

• DOI: 10.2210/pdb3Q2C/pdb

• Classification: IMMUNE SYSTEM
• Organism(s): Homo sapiens
• Mutation(s): No 


• Deposited: 2010-12-20 Released: 2011-07-13 
• Deposition Author(s): Ryu, M., Chen, Y., Qi, J.X., Liu, J., Shi, Y., Cheng, H., Gao, G.F.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.257 
• R-Value Work: 0.225 
• R-Value Observed: 0.226 

Literature

LILRA3 binds both classical and non-classical HLA class I molecules but with reduced affinities compared to LILRB1/LILRB2: structural evidence

Ryu, M., Chen, Y., Qi, J., Liu, J., Fan, Z., Nam, G., Shi, Y., Cheng, H., Gao, G.F.

(2011) PLoS One 6: e19245-e19245

• PubMed: 21559424 
• DOI: 10.1371/journal.pone.0019245
• Primary Citation of Related Structures:  
  3Q2C


• PubMed Abstract: 
  

Structurally, Group 1 LILR (Leukocyte Immunoglobulin (Ig)-Like Receptor, also known as Ig-like transcripts, ILT; Leukocyte Ig-like receptor, LIR; and CD85) members are very similar in terms of the HLAIs (human leukocyte antigen class I molecules) binding region and were hypothesized that they all bind to HLAIs. As one of the Group 1 LILRs, LILRA3 is the only secretory LILR and may greatly control the inhibitory immune response induced by LILRB1, LILRB2, and other HLA-binding LILR molecules like LILRA1. Nevertheless, little was known about the binding of LILRA3 to HLAIs. In this report, we present the crystal structure of the LILRA3 domain 1 (D1) and evaluate the D1 and D1D2 (domain 1 and domain 2) binding to classical and non-classical HLAIs using BIAcore® surface plasmon resonance analysis (SPR). We found that LILRA3 binds both classical HLA-A*0201 and non-classical HLA-G1 but with reduced affinities compared to either LILRB1 or LILRB2. The polymorphic amino acids and the LILRA3 D1 structure support this notion.

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Organizational Affiliation: 

CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Leukocyte immunoglobulin-like receptor subfamily A member 3	A	97	Homo sapiens	Mutation(s): 0  Gene Names: LILRA3, ILT6, LIR4
Find proteins for Q8N6C8 (Homo sapiens) Explore Q8N6C8  Go to UniProtKB:  Q8N6C8

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.50 Å
• R-Value Free: 0.257 
• R-Value Work: 0.225 
• R-Value Observed: 0.226 
• Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 83.308	α = 90
b = 27.817	β = 111.65
c = 48.257	γ = 90

Software Package:

Software Name	Purpose
CrystalClear	data collection
PHASER	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2010-12-20 
• Released Date: 2011-07-13 
Deposition Author(s): Ryu, M., Chen, Y., Qi, J.X., Liu, J., Shi, Y., Cheng, H., Gao, G.F.

Revision History 

• Version 1.0: 2011-07-13
  Type: Initial release