E. coli O157 ParE2-associated antitoxin 2 (PaaA2)

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 5000 
  • Conformers Submitted: 50 
  • Selection Criteria: SAXS DATA 

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Small-Angle X-Ray Scattering- and Nuclear Magnetic Resonance-Derived Conformational Ensemble of the Highly Flexible Antitoxin Paaa2.

Sterckx, Y.G.Volkov, A.N.Vranken, W.F.Kragelj, J.Jensen, M.R.Buts, L.Garcia-Pino, A.Jove, T.Van Melderen, L.Blackledge, M.Van Nuland, N.A.Loris, R.

(2014) Structure 22: 854

  • DOI: https://doi.org/10.1016/j.str.2014.03.012
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Antitoxins from prokaryotic type II toxin-antitoxin modules are characterized by a high degree of intrinsic disorder. The description of such highly flexible proteins is challenging because they cannot be represented by a single structure. Here, we present a combination of SAXS and NMR data to describe the conformational ensemble of the PaaA2 antitoxin from the human pathogen E. coli O157. The method encompasses the use of SAXS data to filter ensembles out of a pool of conformers generated by a custom NMR structure calculation protocol and the subsequent refinement by a block jackknife procedure. The final ensemble obtained through the method is validated by an established residual dipolar coupling analysis. We show that the conformational ensemble of PaaA2 is highly compact and that the protein exists in solution as two preformed helices, connected by a flexible linker, that probably act as molecular recognition elements for toxin inhibition.

  • Organizational Affiliation

    Structural Biology Brussels, Department of Biotechnology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium; Molecular Recognition Unit and Jean Jeener NMR Centre, Structural Biology Research Center, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
PAAA271Escherichia coli O157:H7Mutation(s): 0 
Find proteins for Q8XAD5 (Escherichia coli O157:H7)
Explore Q8XAD5 
Go to UniProtKB:  Q8XAD5
Entity Groups  
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UniProt GroupQ8XAD5
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 5000 
  • Conformers Submitted: 50 
  • Selection Criteria: SAXS DATA 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-01-15
    Type: Initial release
  • Version 1.1: 2014-05-07
    Changes: Database references
  • Version 1.2: 2014-06-25
    Changes: Database references
  • Version 2.0: 2024-01-31
    Changes: Atomic model, Data collection, Database references, Other