3QNX

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.181 

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.,Sect.D 69: 388-397

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

  • 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: 1
MoleculeChainsSequence LengthOrganismDetails
Fab fragment of IMMUNOGLOBULIN A1 LIGHT CHAIN
A
219N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab fragment of IMMUNOGLOBULIN A1 HEAVY CHAIN
B
221N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A, B
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.181 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 49.780α = 90.00
b = 95.850β = 90.00
c = 107.290γ = 90.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
AMoREphasing
PDB_EXTRACTdata extraction
BUSTERrefinement
BUSTER-TNTrefinement
MAR345dtbdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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