8K4T | pdb_00008k4t

Crystal structure of HLA-A*11:01 in complex with KRAS G12C peptide (VVVGACGVGK)

  • Classification: IMMUNE SYSTEM
  • Organism(s): Homo sapiens
  • Expression System: Escherichia coli
  • Mutation(s): Yes 

  • Deposited: 2023-07-20 Released: 2025-01-29 
  • Deposition Author(s): Xu, Y.
  • Funding Organization(s): Ministry of Science and Technology (MoST, China)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 
    0.316 (Depositor), 0.303 (DCC) 
  • R-Value Work: 
    0.258 (Depositor) 
  • R-Value Observed: 
    0.261 (Depositor) 

Starting Model: experimental
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wwPDB Validation 3D Report Full Report

Validation slider image for 8K4T

This is version 1.1 of the entry. See complete history

Literature

Structure guided analysis of KRAS G12 mutants in HLA-A*11:01 reveals a length encoded immunogenic advantage in G12D.

Zhu, J.Chen, Z.Xu, X.Wang, Y.Liu, P.Wen, M.Wang, Q.He, Y.Jin, H.Xue, H.Wang, S.Xu, K.Zhao, L.

(2025) Commun Biol 

  • DOI: https://doi.org/10.1038/s42003-025-09285-0
  • Primary Citation Related Structures: 
    8K4T, 8K4V, 8K50, 9UV8, 9WVE, 9WVF

  • PubMed Abstract: 

    KRAS G12 mutations are frequent oncogenic drivers, yet their differential immunogenicity complicates T cell-based therapies. Here, we integrate structural, biophysical, and functional analyses to examine how KRAS G12 variants remodel peptide-MHC-I (pMHC) architecture and T cell receptor (TCR) recognition. Using HLA-A*11:01, we show that single residue substitutions at position 12 induce distinct conformational changes in the MHC groove, with G12D uniquely destabilizing the complex through a buried aspartate side chain. Notably, G12D peptides adopt two registers, a 9-mer and a 10-mer, that diverge sharply in structure and immunogenicity. The 10-mer forms a compact, stable pMHC with a TCR-accessible surface, while the 9-mer adopts a bent conformation incompatible with recognition. Molecular dynamics and NMR titration confirm the superior stability and binding affinity of the 10-mer. These results highlight how peptide length and conformation critically shape immune visibility, offering mechanistic insight for optimizing TCR-T therapies against elusive neoantigens like KRAS G12D.


  • Organizational Affiliation
    • Department of Anesthesiology, Putuo People's Hospital, School of Medicine, Tongji University, Shanghai, China.

Macromolecule Content 

  • Total Structure Weight: 94.08 kDa 
  • Atom Count: 6,213 
  • Modeled Residue Count: 763 
  • Deposited Residue Count: 816 
  • Unique protein chains: 3

Macromolecules

Find similar proteins by:|  3D Structure
Entity ID: 1
MoleculeChains  Sequence LengthOrganismDetailsImage
HLA class I histocompatibility antigen, A alpha chain
A, D
276Homo sapiensMutation(s): 3 
Gene Names: HLA-AHLAA
UniProt & NIH Common Fund Data Resources
Find proteins for P04439 (Homo sapiens)
Explore P04439 
Go to UniProtKB:  P04439
PHAROS:  P04439
GTEx:  ENSG00000206503 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP04439
Sequence Annotations
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Reference Sequence
Find similar proteins by:|  3D Structure
Entity ID: 2
MoleculeChains  Sequence LengthOrganismDetailsImage
Beta-2-microglobulin
B, E
122Homo sapiensMutation(s): 0 
Gene Names: B2MCDABP0092HDCMA22P
UniProt & NIH Common Fund Data Resources
Find proteins for P61769 (Homo sapiens)
Explore P61769 
Go to UniProtKB:  P61769
PHAROS:  P61769
GTEx:  ENSG00000166710 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP61769
Sequence Annotations
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Reference Sequence
Find similar proteins by:  Sequence   |   3D Structure  
Entity ID: 3
MoleculeChains  Sequence LengthOrganismDetailsImage
KRAS G12C peptide (VVVGACGVGK)
C, F
10Homo sapiensMutation(s): 1 
Gene Names: KRASKRAS2RASK2
EC: 3.6.5.2
UniProt & NIH Common Fund Data Resources
Find proteins for P01116 (Homo sapiens)
Explore P01116 
Go to UniProtKB:  P01116
PHAROS:  P01116
GTEx:  ENSG00000133703 
Entity Groups
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01116
Sequence Annotations
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Reference Sequence

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free:  0.316 (Depositor), 0.303 (DCC) 
  • R-Value Work:  0.258 (Depositor) 
  • R-Value Observed: 0.261 (Depositor) 
Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 48.708α = 105.864
b = 63.579β = 92.656
c = 75.507γ = 97.701
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata scaling
Cootmodel building
PHENIXphasing

Structure Validation

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Entry History 

& Funding Information

Deposition Data

  • Released Date: 2025-01-29 
  • Deposition Author(s): Xu, Y.

Funding OrganizationLocationGrant Number
Ministry of Science and Technology (MoST, China)China2021YFA1302200

Revision History  (Full details and data files)

  • Version 1.0: 2025-01-29
    Type: Initial release
  • Version 1.1: 2025-12-24
    Changes: Database references