1N43

Streptavidin Mutant N23A with biotin at 1.89A


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.89 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history


Literature

Structural studies of hydrogen bonds in the high-affinity streptavidin-biotin complex: mutations of amino acids interacting with the ureido oxygen of biotin.

Le Trong, I.Freitag, S.Klumb, L.A.Chu, V.Stayton, P.S.Stenkamp, R.E.

(2003) Acta Crystallogr D Biol Crystallogr 59: 1567-1573

  • DOI: https://doi.org/10.1107/s0907444903014562
  • Primary Citation of Related Structures:  
    1N43, 1N4J, 1N7Y, 1N9M, 1N9Y, 1NBX, 1NC9, 1NDJ

  • PubMed Abstract: 

    An elaborate hydrogen-bonding network contributes to the tight binding of biotin to streptavidin. The specific energetic contributions of hydrogen bonds to the biotin ureido oxygen have previously been investigated by mapping the equilibrium and activation thermodynamic signatures of N23A, N23E, S27A, Y43A and Y43F site-directed mutants [Klumb et al. (1998), Biochemistry, 37, 7657-7663]. The crystal structures of these variants in the unbound and biotin-bound states provide structural insight into the energetic alterations and are described here. High (1.5-2.2 A) to atomic resolution (1.14 A) structures were obtained and structural models were refined to R values ranging from 0.12 to 0.20. The overall folding of streptavidin as described previously has not changed in any of the mutant structures. Major deviations such as side-chain shifts of residues in the binding site are observed only for the N23A and Y43A mutations. In none of the mutants is a systematic shift of biotin observed when one of the hydrogen-bonding partners to the ureido oxygen of biotin is removed. Recent thermodynamic studies report increases of DeltaDeltaG(o) of 5.0-14.6 kJ mol(-1) for these mutants with respect to the wild-type protein. The decreasing stabilities of the complexes of the mutants are discussed in terms of their structures.


  • Organizational Affiliation

    Department of Biological Structure and Biomolecular Structure Center, University of Washington, Box 357420, Seattle, Washington 98195-7420, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Streptavidin
A, B, C, D
127Streptomyces avidiniiMutation(s): 1 
Gene Names: core streptavidin
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: 1.89 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.192 
  • R-Value Observed: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.18α = 90
b = 97.2β = 112.6
c = 51.58γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHELXmodel building
SHELXL-97refinement
SHELXphasing

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-09-02
    Type: Initial release
  • Version 1.1: 2008-04-28
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations
  • Version 1.4: 2024-02-14
    Changes: Data collection, Refinement description