3M8O

Human IgA1 Fab fragment


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.153 
  • R-Value Observed: 0.154 

wwPDB Validation 3D Report Full Report


This is version 1.3 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: 1
MoleculeChainsSequence LengthOrganismDetails
IMMUNOGLOBULIN A1 LIGHT CHAINL219Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence

Find similar proteins by: Sequence  |  Structure

Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
IMMUNOGLOBULIN A1 HEAVY CHAINH221Homo sapiensMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download CCD File 
H, L
GLYCEROL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download CCD File 
H, L
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.55 Å
  • R-Value Free: 0.182 
  • R-Value Work: 0.153 
  • R-Value Observed: 0.154 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 43.78α = 90
b = 76.3β = 105.48
c = 55.85γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
AMoREphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
MAR345dtbdata collection
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-03-30
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2013-02-27
    Changes: Database references, Refinement description
  • Version 1.3: 2014-02-19
    Changes: Database references