3QNX

Orthorhombic form of human IgA1 Fab fragment, sharing same Fv as IgG


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.184 

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
  • Structures With Same Primary Citation

  • 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 c ...

    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: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab fragment of IMMUNOGLOBULIN A1 HEAVY CHAINB221Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Fab fragment of IMMUNOGLOBULIN A1 LIGHT CHAINA219Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
A, B
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.184 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 49.78α = 90
b = 95.85β = 90
c = 107.29γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
BUSTER-TNTrefinement
PDB_EXTRACTdata extraction
MAR345dtbdata collection
AMoREphasing
BUSTERrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • 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