1G6V

Complex of the camelid heavy-chain antibody fragment CAB-CA05 with bovine carbonic anhydrase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.50 Å
  • R-Value Free: 0.276 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Antigen specificity and high affinity binding provided by one single loop of a camel single-domain antibody.

Desmyter, A.Decanniere, K.Muyldermans, S.Wyns, L.

(2001) J Biol Chem 276: 26285-26290

  • DOI: 10.1074/jbc.M102107200
  • Primary Citation of Related Structures:  
    1G6V

  • PubMed Abstract: 
  • Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal structures of an antibody fragment derived from a camel heavy c ...

    Detailed knowledge on antibody-antigen recognition is scarce given the unlimited antibody specificities of which only few have been investigated at an atomic level. We report the crystal structures of an antibody fragment derived from a camel heavy chain antibody against carbonic anhydrase, free and in complex with antigen. Surprisingly, this single-domain antibody interacts with nanomolar affinity with the antigen through its third hypervariable loop (19 amino acids long), providing a flat interacting surface of 620 A(2). For the first time, a single-domain antibody is observed with its first hypervariable loop adopting a type-1 canonical structure. The second hypervariable loop, of unique size due to a somatic mutation, reveals a regular beta-turn. The third hypervariable loop covers the remaining hypervariable loops and the side of the domain that normally interacts with the variable domain of the light chain. Specific amino acid substitutions and reoriented side chains reshape this side of the domain and increase its hydrophilicity. Of interest is the substitution of the conserved Trp-103 by Arg because it opens new perspectives to 'humanize' a camel variable domain of heavy chain of heavy chain antibody (VHH) or to 'camelize' a human or a mouse variable domain of heavy chain of conventional antibody (VH).


    Organizational Affiliation

    Department Ultrastructure, Vlaams Interuniversitair Instituut voor Biotechnologie, Vrije Universiteit Brussel, Paardenstraat 65, B-1640 Sint Genesius Rode, Belgium. aldesmtr@vub.ac.be



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CARBONIC ANHYDRASEA260Bos taurusMutation(s): 0 
Gene Names: CA2
EC: 4.2.1.1
Find proteins for P00921 (Bos taurus)
Explore P00921 
Go to UniProtKB:  P00921
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
ANTIBODY HEAVY CHAINK126Camelus dromedariusMutation(s): 0 
Protein Feature View
Expand
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.50 Å
  • R-Value Free: 0.276 
  • R-Value Work: 0.210 
  • R-Value Observed: 0.210 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.86α = 90
b = 83.86β = 90
c = 224.05γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALAdata scaling
AMoREphasing
CNSrefinement
CCP4data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-11-22
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance