1XF3

Structure of ligand-free Fab DNA-1 in space group P65


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Evidence for Structural Plasticity of Heavy Chain Complementarity-determining Region 3 in Antibody-ssDNA Recognition

Schuermann, J.P.Prewitt, S.P.Davies, C.Deutscher, S.L.Tanner, J.J.

(2005) J.Mol.Biol. 347: 965-978

  • DOI: 10.1016/j.jmb.2005.02.008
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Anti-DNA antibodies play important roles in the pathogenesis of autoimmune diseases. They also represent a unique and relatively unexplored class of DNA-binding protein. Here, we present a study of conformational changes induced by DNA binding to an ...

    Anti-DNA antibodies play important roles in the pathogenesis of autoimmune diseases. They also represent a unique and relatively unexplored class of DNA-binding protein. Here, we present a study of conformational changes induced by DNA binding to an anti-ssDNA Fab known as DNA-1. Three crystal structures are reported: a complex of DNA-1 bound to dT3, and two structures of the ligand-free Fab. One of the ligand-free structures was determined from crystals exhibiting perfect hemihedral twinning, and the details of structure determination are provided. Unexpectedly, five residues (H97-H100A) in the apex of heavy chain complementarity-determining region 3 (HCDR3) are disordered in both ligand-free structures. Ligand binding also caused a 2-4A shift of the backbone of Tyr L92 and ordering of the L92 side-chain. In contrast, these residues are highly ordered in the Fab/dT3 complex, where Tyr H100 and Tyr H100A form intimate stacking interactions with DNA bases, and L92 forms the 5' end of the binding site. The structures suggest that HCDR3 is very flexible and adopts multiple conformations in the ligand-free state. These results are discussed in terms of induced fit and pre-existing equilibrium theories of ligand binding. Our results allow new interpretations of existing thermodynamic and mutagenesis data in terms of conformational entropy and the volume of conformational space accessible to HCDR3 in the ligand-free state. In the context of autoimmune disease, plasticity of the ligand-free antibody could provide a mechanism by which anti-DNA antibodies bind diverse host ligands, and thereby contribute to pathogenicity.


    Organizational Affiliation

    Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Fab Light chain
L, A
214N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab heavy chain
H, B
230N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.208 
  • Space Group: P 65
Unit Cell:
Length (Å)Angle (°)
a = 201.751α = 90.00
b = 201.751β = 90.00
c = 44.781γ = 120.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
AMoREphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-04-12
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.3: 2017-10-11
    Type: Advisory, Refinement description