3QO1

Monoclinic form of IgG1 Fab fragment (apo form) sharing same Fv as IgA


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.169 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structure of a human IgA1 Fab fragment at 1.55 angstrom resolution: potential effect of the constant domains on antigen-affinity modulation

Correa, A.Trajtenberg, F.Obal, G.Pritsch, O.Dighiero, G.Oppezzo, P.Buschiazzo, A.

(2013) Acta Crystallogr D Biol Crystallogr 69: 388-397

  • DOI: 10.1107/S0907444912048664
  • Primary Citation of Related Structures:  
    3QNX, 3QNY, 3QNZ, 3QO1, 3M8O

  • PubMed Abstract: 
  • Despite being the most abundant class of immunoglobulins in humans and playing central roles in the adaptive immune response, high-resolution structural data are still lacking for the antigen-binding region of human isotype A antibodies (IgAs). The crystal structures of a human Fab fragment of IgA1 in three different crystal forms are now reported ...

    Despite being the most abundant class of immunoglobulins in humans and playing central roles in the adaptive immune response, high-resolution structural data are still lacking for the antigen-binding region of human isotype A antibodies (IgAs). The crystal structures of a human Fab fragment of IgA1 in three different crystal forms are now reported. The three-dimensional organization is similar to those of other Fab classes, but FabA1 seems to be more rigid, being constrained by a hydrophobic core in the interface between the variable and constant domains of the heavy chain (VH-CH1) as well as by a disulfide bridge that connects the light and heavy chains, influencing the relative heavy/light-chain orientation. The crystal structure of the same antibody but with a G-isotype CH1 which is reported to display different antigen affinity has also been solved. The differential structural features reveal plausible mechanisms for constant/variable-domain long-distance effects whereby antibody class switching could alter antigen affinity.


    Organizational Affiliation

    Unit of Recombinant Proteins, Institut Pasteur de Montevideo, 11400 Montevideo, Uruguay.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Fab fragment of IMMUNOGLOBULIN G1 LIGHT CHAINA219Homo sapiensMutation(s): 0 
Protein Feature View
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Fab fragment of IMMUNOGLOBULIN G1 HEAVY CHAINB220Homo sapiensMutation(s): 0 
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download Ideal Coordinates CCD File 
C [auth A], D [auth B]GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.166 
  • R-Value Observed: 0.169 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.297α = 90
b = 67.214β = 103.39
c = 68.952γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
AMoREphasing
BUSTER-TNTrefinement
PDB_EXTRACTdata extraction
MAR345dtbdata collection
XDSdata reduction
BUSTERrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-02-15
    Type: Initial release
  • Version 1.1: 2013-02-27
    Changes: Database references
  • Version 1.2: 2014-03-05
    Changes: Database references