1QKX

Alpha-spectrin Src Homology 3 domain, N47A mutant in the distal loop.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.216 
  • R-Value Observed: 0.216 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Thermodynamic and structural characterization of Asn and Ala residues in the disallowed II' region of the Ramachandran plot.

Vega, M.C.Martinez, J.C.Serrano, L.

(2000) Protein Sci 9: 2322-2328

  • DOI: 10.1110/ps.9.12.2322
  • Primary Citation of Related Structures:  
    1QKX, 1QKW

  • PubMed Abstract: 
  • Residue Asn47 at position L1 of a type II' beta-turn of the alpha-spectrin SH3 domain is located in a disallowed region of the Ramachandran plot (phi = 56 +/- 12, psi = -118 +/- 17). Therefore, it is expected that replacement of Asn47 by Gly should result in a considerable stabilization of the protein ...

    Residue Asn47 at position L1 of a type II' beta-turn of the alpha-spectrin SH3 domain is located in a disallowed region of the Ramachandran plot (phi = 56 +/- 12, psi = -118 +/- 17). Therefore, it is expected that replacement of Asn47 by Gly should result in a considerable stabilization of the protein. Thermodynamic analysis of the N47G and N47A mutants shows that the change in free energy is small (approximately 0.7 kcal/mol; approximately 3 kJ/mol) and comparable to that found when mutating a Gly to Ala in a alpha-helix or beta-sheet. X-ray structural analysis of these mutants shows that the conformation of the beta-turn does not change upon mutation and, therefore, that there is no relaxation of the structure, nor is there any gain or loss of interactions that could explain the small energy change. Our results indicate that the energetic definition of II' region of the Ramachandran plot (phi = 60 +/- 30, psi = -115 +/- 15) should be revised for at least Ala and Asn in structure validation and protein design.


    Organizational Affiliation

    EMBL, Heidelberg, Germany.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
SPECTRIN ALPHA CHAINA62Gallus gallusMutation(s): 1 
Gene Names: SPTAN1SPTA2
Find proteins for P07751 (Gallus gallus)
Explore P07751 
Go to UniProtKB:  P07751
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.275 
  • R-Value Work: 0.216 
  • R-Value Observed: 0.216 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 33.6α = 90
b = 42.24β = 90
c = 49.69γ = 90
Software Package:
Software NamePurpose
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2000-12-15
    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: 2019-10-09
    Changes: Advisory, Data collection, Database references