3IQO

1.5 angstrom X-ray structure of bovine Ca(2+)-S100B


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.202 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Effects of CapZ Peptide (TRTK-12) Binding to S100B-Ca(2+) as Examined by NMR and X-ray Crystallography

Charpentier, T.H.Thompson, L.E.Liriano, M.A.Varney, K.M.Wilder, P.T.Pozharski, E.Toth, E.A.Weber, D.J.

(2010) J Mol Biol 396: 1227-1243

  • DOI: 10.1016/j.jmb.2009.12.057
  • Primary Citation of Related Structures:  
    3IQO, 3IQQ

  • PubMed Abstract: 
  • Structure-based drug design is underway to inhibit the S100B-p53 interaction as a strategy for treating malignant melanoma. X-ray crystallography was used here to characterize an interaction between Ca(2)(+)-S100B and TRTK-12, a target that binds to the p53-binding site on S100B ...

    Structure-based drug design is underway to inhibit the S100B-p53 interaction as a strategy for treating malignant melanoma. X-ray crystallography was used here to characterize an interaction between Ca(2)(+)-S100B and TRTK-12, a target that binds to the p53-binding site on S100B. The structures of Ca(2+)-S100B (1.5-A resolution) and S100B-Ca(2)(+)-TRTK-12 (2.0-A resolution) determined here indicate that the S100B-Ca(2+)-TRTK-12 complex is dominated by an interaction between Trp7 of TRTK-12 and a hydrophobic binding pocket exposed on Ca(2+)-S100B involving residues in helices 2 and 3 and loop 2. As with an S100B-Ca(2)(+)-p53 peptide complex, TRTK-12 binding to Ca(2+)-S100B was found to increase the protein's Ca(2)(+)-binding affinity. One explanation for this effect was that peptide binding introduced a structural change that increased the number of Ca(2+) ligands and/or improved the Ca(2+) coordination geometry of S100B. This possibility was ruled out when the structures of S100B-Ca(2+)-TRTK-12 and S100B-Ca(2+) were compared and calcium ion coordination by the protein was found to be nearly identical in both EF-hand calcium-binding domains (RMSD=0.19). On the other hand, B-factors for residues in EF2 of Ca(2+)-S100B were found to be significantly lowered with TRTK-12 bound. This result is consistent with NMR (15)N relaxation studies that showed that TRTK-12 binding eliminated dynamic properties observed in Ca(2+)-S100B. Such a loss of protein motion may also provide an explanation for how calcium-ion-binding affinity is increased upon binding a target. Lastly, it follows that any small-molecule inhibitor bound to Ca(2+)-S100B would also have to cause an increase in calcium-ion-binding affinity to be effective therapeutically inside a cell, so these data need to be considered in future drug design studies involving S100B.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 108 North Greene Street, Baltimore, MD 21201, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein S100-BA, B92Bos taurusMutation(s): 0 
Gene Names: S100B
UniProt
Find proteins for P02638 (Bos taurus)
Explore P02638 
Go to UniProtKB:  P02638
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.200 
  • R-Value Observed: 0.202 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.637α = 90
b = 35.044β = 92.62
c = 58.113γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-02-02
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description