2Y3E

Traptavidin, apo-form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.178 
  • R-Value Work: 0.134 
  • R-Value Observed: 0.135 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

How the Biotin-Streptavidin Interaction Was Made Even Stronger: Investigation Via Crystallography and a Chimeric Tetramer.

Chivers, C.E.Koner, A.L.Lowe, E.D.Howarth, M.

(2011) Biochem J 435: 55

  • DOI: https://doi.org/10.1042/BJ20101593
  • Primary Citation of Related Structures:  
    2Y3E, 2Y3F

  • PubMed Abstract: 

    The interaction between SA (streptavidin) and biotin is one of the strongest non-covalent interactions in Nature. SA is a widely used tool and a paradigm for protein-ligand interactions. We previously developed a SA mutant, termed Tr (traptavidin), possessing a 10-fold lower off-rate for biotin, with increased mechanical and thermal stability. In the present study, we determined the crystal structures of apo-Tr and biotin-Tr at 1.5 Å resolution. In apo-SA the loop (L3/4), near biotin's valeryl tail, is typically disordered and open, but closes upon biotin binding. In contrast, L3/4 was shut in both apo-Tr and biotin-Tr. The reduced flexibility of L3/4 and decreased conformational change on biotin binding provide an explanation for Tr's reduced biotin off- and on-rates. L3/4 includes Ser45, which forms a hydrogen bond to biotin consistently in Tr, but erratically in SA. Reduced breakage of the biotin-Ser45 hydrogen bond in Tr is likely to inhibit the initiating event in biotin's dissociation pathway. We generated a Tr with a single biotin-binding site rather than four, which showed a simi-larly low off-rate, demonstrating that Tr's low off-rate was governed by intrasubunit effects. Understanding the structural features of this tenacious interaction may assist the design of even stronger affinity tags and inhibitors.


  • Organizational Affiliation

    Department of Biochemistry, Oxford University, South Parks Road, Oxford OX1 3QU, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
STREPTAVIDIN
A, B
134Streptomyces avidiniiMutation(s): 2 
UniProt
Find proteins for P22629 (Streptomyces avidinii)
Explore P22629 
Go to UniProtKB:  P22629
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP22629
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.178 
  • R-Value Work: 0.134 
  • R-Value Observed: 0.135 
  • Space Group: I 41
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 57.594α = 90
b = 57.594β = 90
c = 183.354γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-02-16
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-20
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description