7DC6 | pdb_00007dc6

Giant panda MHC class I complexes


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.68 Å
  • R-Value Free: 
    0.291 (Depositor), 0.291 (DCC) 
  • R-Value Work: 
    0.266 (Depositor), 0.266 (DCC) 
  • R-Value Observed: 
    0.268 (Depositor) 

Starting Model: experimental
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This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the giant panda MHC class I complex: First insights into the viral peptide presentation profile in the bear family.

Yuan, H.Ma, L.Zhang, L.Li, X.Xia, C.

(2020) Protein Sci 29: 2468-2481

  • DOI: https://doi.org/10.1002/pro.3980
  • Primary Citation Related Structures: 
    7DC6

  • PubMed Abstract: 

    The viral cytotoxic T lymphocyte (CTL) epitope peptides presented by classical MHC-I molecules require the assembly of a peptide-MHC-I-β2m (pMHC-I) trimolecular complex for T cell receptor (TCR) recognition, which is the critical activation link for triggering antiviral T cell immunity. Research on T cell immunology in the Ursidae family, especially structural immunology, is still lacking. In this study, the structure of the key trimolecular complex pMHC-I, which binds a peptide from canine distemper virus, was solved for the first time using giant panda as a representative species of Ursidae. The structural characteristics of the giant panda pMHC-I complex (pAime-128), including the unique pockets in the peptide-binding groove (PBG), were analyzed in detail. Comparing the pAime-128 to others in the bear family and extending the comparison to other mammals revealed distinct features. The interaction between MHC-I and β2m, the features of pAime-128 involved in TCR docking and cluster of differentiation 8 (CD8) binding, the anchor sites in the PBG, and the CTL epitopes of potential viruses that infect pandas were clarified. Unique features of pMHC-I viral antigen presentation in the panda were revealed by solving the three-dimensional (3D) structure of pAime-128. The distinct characteristics of pAime-128 indicate an unusual event that emerged during the evolution of the MHC system in the bear family. These results provide a new platform for research on panda CTL immunity and the design of vaccines for application in the bear family.


  • Organizational Affiliation
    • Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing, China.

Macromolecule Content 

  • Total Structure Weight: 88.9 kDa 
  • Atom Count: 6,298 
  • Modeled Residue Count: 765 
  • Deposited Residue Count: 766 
  • Unique protein chains: 3

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
MHC class I antigen
A, C
275Ailuropoda melanoleucaMutation(s): 0 
Gene Names: Aime-128
UniProt
Find proteins for B2KT53 (Ailuropoda melanoleuca)
Explore B2KT53 
Go to UniProtKB:  B2KT53
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB2KT53
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Beta-2-microglobulin
B, D
99Ailuropoda melanoleucaMutation(s): 0 
Gene Names: B2MPANDA_000996
UniProt
Find proteins for A0A7N5K2L4 (Ailuropoda melanoleuca)
Explore A0A7N5K2L4 
Go to UniProtKB:  A0A7N5K2L4
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A7N5K2L4
Sequence Annotations
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Reference Sequence
Find similar proteins by:  Sequence   |   3D Structure  
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
CCV-NGY9 peptide from Spike protein
E, F
9Canine coronavirusMutation(s): 0 
UniProt
Find proteins for P10033 (Feline coronavirus (strain FIPV WSU-79/1146))
Explore P10033 
Go to UniProtKB:  P10033
Entity Groups
UniProt GroupP10033
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.68 Å
  • R-Value Free:  0.291 (Depositor), 0.291 (DCC) 
  • R-Value Work:  0.266 (Depositor), 0.266 (DCC) 
  • R-Value Observed: 0.268 (Depositor) 
Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 173.677α = 90
b = 173.677β = 90
c = 84.346γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
HKL-2000data scaling
REFMACphasing

Structure Validation

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Entry History 

& Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Natural Science Foundation of China (NSFC)China31572493
National Natural Science Foundation of China (NSFC)China31972683

Revision History  (Full details and data files)

  • Version 1.0: 2021-06-16
    Type: Initial release
  • Version 1.1: 2023-11-29
    Changes: Data collection, Database references, Refinement description
  • Version 1.2: 2024-10-16
    Changes: Structure summary