1L7I

Crystal Structure of the anti-ErbB2 Fab2C4


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Comprehensive functional maps of the antigen-binding site of an anti-ErbB2 antibody obtained with shotgun scanning mutagenesis.

Vajdos, F.F.Adams, C.W.Breece, T.N.Presta, L.G.de Vos, A.M.Sidhu, S.S.

(2002) J Mol Biol 320: 415-428

  • DOI: 10.1016/S0022-2836(02)00264-4
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Shotgun scanning combinatorial mutagenesis was used to study the antigen-binding site of Fab2C4, a humanized monoclonal antibody fragment that binds to the extracellular domain of the human oncogene product ErbB2. Essentially all the residues in the ...

    Shotgun scanning combinatorial mutagenesis was used to study the antigen-binding site of Fab2C4, a humanized monoclonal antibody fragment that binds to the extracellular domain of the human oncogene product ErbB2. Essentially all the residues in the Fab2C4 complementarity determining regions (CDRs) were alanine-scanned using phage-displayed libraries that preferentially allowed side-chains to vary as the wild-type or alanine. A separate homolog-scan was performed using libraries that allowed side-chains to vary only as the wild-type or a similar amino acid residue. Following binding selections to isolate functional clones, DNA sequencing was used to determine the wild-type/mutant ratios at each varied position, and these ratios were used to assess the contributions of each side-chain to antigen binding. The alanine-scan revealed that most of the side-chains that contribute to antigen binding are located in the heavy chain, and the Fab2C4 three-dimensional structure revealed that these residues fall into two groups. The first group consists of solvent-exposed residues which likely make energetically favorable contacts with the antigen and thus comprise the functional-binding epitope. The second group consists of buried residues with side-chains that pack against other CDR residues and apparently act as scaffolding to maintain the functional epitope in a binding-competent conformation. The homolog-scan involved subtle mutations, and as a result, only a subset of the side-chains that were intolerant to alanine substitutions were also intolerant to homologous substitutions. In particular, the 610 A2 functional epitope surface revealed by alanine-scanning shrunk to only 369 A2 when mapped with homologous substitutions, suggesting that this smaller subset of side-chains may be involved in more precise contacts with the antigen. The results validate shotgun scanning as a rapid and accurate method for determining the functional contributions of individual side-chains involved in protein-protein interactions.


    Organizational Affiliation

    Department of Protein Engineering, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
chimera of Fab2C4: "humanized" murine monoclonal antibodyL214Homo sapiensMutation(s): 0 
Find proteins for Q7Z3Y4 (Homo sapiens)
Explore Q7Z3Y4 
Go to UniProtKB:  Q7Z3Y4
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
chimera of Fab2C4: "humanized" murine monoclonal antibodyH222Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download CCD File 
L
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.197 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.966α = 90
b = 64.249β = 105.44
c = 79.445γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
AMoREphasing
CNXrefinement
CCP4data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-07-10
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance