1I8M

CRYSTAL STRUCTURE OF A RECOMBINANT ANTI-SINGLE-STRANDED DNA ANTIBODY FRAGMENT COMPLEXED WITH DT5


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.220 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Crystal Structure of an Antigen-Binding Fragment Bound to Single-Stranded DNA

Tanner, J.J.Komissarov, A.A.Deutscher, S.L.

(2001) J Mol Biol 314: 807-822

  • DOI: https://doi.org/10.1006/jmbi.2001.5178
  • Primary Citation of Related Structures:  
    1I8M

  • PubMed Abstract: 

    Antibodies to DNA are characteristic of the autoimmune disease systemic lupus erythematosus (SLE) and they also serve as models for the study of protein-DNA recognition. Anti-DNA antibodies often play an important role in disease pathogenesis by mediating kidney damage via antibody-DNA immune complex formation. The structural underpinnings of anti-DNA antibody pathogenicity and antibody-DNA recognition, however, are not well understood, due in part to the lack of direct, experimental three-dimensional structural information on antibody-DNA complexes. To address these issues for anti-single-stranded DNA antibodies, we have determined the 2.1 A crystal structure of a recombinant Fab (DNA-1) in complex with dT5. DNA-1 was previously isolated from a bacteriophage Fab display library from the immunoglobulin repertoire of an SLE-prone mouse. The structure shows that DNA-1 binds oligo(dT) primarily by sandwiching thymine bases between Tyr side-chains, which allows the bases to make sequence-specific hydrogen bonds. The critical stacking Tyr residues are L32, L49, H100, and H100A, while His L91 and Asn L50 contribute hydrogen bonds. Comparison of the DNA-1 structure to other anti-nucleic acid Fab structures reveals a common ssDNA recognition module consisting of Tyr L32, a hydrogen bonding residue at position L91, and an aromatic side-chain from the tip of complementarity determining region H3. The structure also provides a framework for interpreting previously determined thermodynamics data, and this analysis suggests that hydrophobic desolvation might underlie the observed negative enthalpy of binding. Finally, Arg side-chains from complementarity determining region H3 appear to play a novel role in DNA-1. Rather than forming ion pairs with dT5, Arg contributes to oligo(dT) recognition by helping to maintain the structural integrity of the combining site. This result is significant because antibody pathogenicity is thought to be correlated to the Arg content of anti-DNA antibody hypervariable loops.


  • Organizational Affiliation

    Department of Chemistry, University of Missouri-Columbia, Columbia, MO 65211, USA. tannerjj@missouri.edu


Macromolecules

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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
ANTIBODY LIGHT CHAIN FABC [auth L],
E [auth A]
214Mus musculusMutation(s): 0 
UniProt
Find proteins for Q7TS98 (Mus musculus)
Explore Q7TS98 
Go to UniProtKB:  Q7TS98
Entity Groups  
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UniProt GroupQ7TS98
Sequence Annotations
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  • Reference Sequence
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Entity ID: 4
MoleculeChains Sequence LengthOrganismDetailsImage
ANTIBODY HEAVY CHAIN FABD [auth H],
F [auth B]
224Mus musculusMutation(s): 0 
UniProt
Find proteins for Q924Q6 (Mus musculus)
Explore Q924Q6 
Go to UniProtKB:  Q924Q6
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UniProt GroupQ924Q6
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  • Reference Sequence

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Entity ID: 1
MoleculeChains LengthOrganismImage
5'-D(*TP*TP*TP*TP*T)-3'A [auth T]5N/A
Sequence Annotations
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  • Reference Sequence

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Entity ID: 2
MoleculeChains LengthOrganismImage
5'-D(P*TP*T)-3'B [auth D]2N/A
Sequence Annotations
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
G [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.220 
  • Space Group: P 65 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 171.84α = 90
b = 171.84β = 90
c = 144.568γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
X-PLORmodel building
CNSrefinement
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-12-07
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description
  • Version 1.4: 2023-08-09
    Changes: Data collection, Database references, Derived calculations, Refinement description