6B3S

Crystal structure of the Fab fragment of necitumumab (Fab11F8) in complex with domain III from a cetuximab resistant variant of EGFR (sEGFRd3-S468R)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.209 

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This is version 2.1 of the entry. See complete history


Literature

Molecular Basis for Necitumumab Inhibition of EGFR Variants Associated with Acquired Cetuximab Resistance.

Bagchi, A.Haidar, J.N.Eastman, S.W.Vieth, M.Topper, M.Iacolina, M.D.Walker, J.M.Forest, A.Shen, Y.Novosiadly, R.D.Ferguson, K.M.

(2018) Mol Cancer Ther 17: 521-531

  • DOI: https://doi.org/10.1158/1535-7163.MCT-17-0575
  • Primary Citation of Related Structures:  
    6B3S

  • PubMed Abstract: 

    Acquired resistance to cetuximab, an antibody that targets the EGFR, impacts clinical benefit in head and neck, and colorectal cancers. One of the mechanisms of resistance to cetuximab is the acquisition of mutations that map to the cetuximab epitope on EGFR and prevent drug binding. We find that necitumumab, another FDA-approved EGFR antibody, can bind to EGFR that harbors the most common cetuximab-resistant substitution, S468R (or S492R, depending on the amino acid numbering system). We determined an X-ray crystal structure to 2.8 Å resolution of the necitumumab Fab bound to an S468R variant of EGFR domain III. The arginine is accommodated in a large, preexisting cavity in the necitumumab paratope. We predict that this paratope shape will be permissive to other epitope substitutions, and show that necitumumab binds to most cetuximab- and panitumumab-resistant EGFR variants. We find that a simple computational approach can predict with high success which EGFR epitope substitutions abrogate antibody binding. This computational method will be valuable to determine whether necitumumab will bind to EGFR as new epitope resistance variants are identified. This method could also be useful for rapid evaluation of the effect on binding of alterations in other antibody/antigen interfaces. Together, these data suggest that necitumumab may be active in patients who are resistant to cetuximab or panitumumab through EGFR epitope mutation. Furthermore, our analysis leads us to speculate that antibodies with large paratope cavities may be less susceptible to resistance due to mutations mapping to the antigen epitope. Mol Cancer Ther; 17(2); 521-31. ©2017 AACR .


  • Organizational Affiliation

    Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Epidermal growth factor receptorA,
D [auth B],
G [auth E],
J [auth I]
214Homo sapiensMutation(s): 1 
Gene Names: EGFRERBBERBB1HER1
EC: 2.7.10.1
UniProt & NIH Common Fund Data Resources
Find proteins for P00533 (Homo sapiens)
Explore P00533 
Go to UniProtKB:  P00533
PHAROS:  P00533
GTEx:  ENSG00000146648 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP00533
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Necitumumab Fab Heavy chainB [auth H],
E [auth C],
H [auth F],
K [auth J]
222Homo sapiensMutation(s): 0 
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Sequence Annotations
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  • Reference Sequence
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Necitumumab Fab Light chainC [auth L],
F [auth D],
I [auth G],
L [auth K]
213Homo sapiensMutation(s): 0 
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Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
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  • Reference Sequence
Oligosaccharides

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Entity ID: 4
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
M, O, Q, S, T
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Entity ID: 5
MoleculeChains Length2D Diagram Glycosylation3D Interactions
beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
N
3N-Glycosylation
Glycosylation Resources
GlyTouCan:  G15407YE
GlyCosmos:  G15407YE
GlyGen:  G15407YE
Entity ID: 6
MoleculeChains Length2D Diagram Glycosylation3D Interactions
alpha-D-mannopyranose-(1-3)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
P, R
4N-Glycosylation
Glycosylation Resources
GlyTouCan:  G81315DD
GlyCosmos:  G81315DD
GlyGen:  G81315DD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.245 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.209 
  • Space Group: P 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 151.943α = 90
b = 80.756β = 91.5
c = 172.901γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction
PHASERphasing

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Cancer Institute (NIH/NCI)United StatesR01-CA112552
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesT32-GM008275

Revision History  (Full details and data files)

  • Version 1.0: 2017-12-06
    Type: Initial release
  • Version 1.1: 2018-02-21
    Changes: Database references
  • Version 1.2: 2019-12-04
    Changes: Author supporting evidence
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description, Structure summary