4PE0

Crystal Structure of Calcium-loaded S100B bound to SBi4434


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.08 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.192 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Covalent Small Molecule Inhibitors of Ca(2+)-Bound S100B.

Cavalier, M.C.Pierce, A.D.Wilder, P.T.Alasady, M.J.Hartman, K.G.Neau, D.B.Foley, T.L.Jadhav, A.Maloney, D.J.Simeonov, A.Toth, E.A.Weber, D.J.

(2014) Biochemistry 53: 6628-6640

  • DOI: 10.1021/bi5005552
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Elevated levels of the tumor marker S100B are observed in malignant melanoma, and this EF-hand-containing protein was shown to directly bind wild-type (wt) p53 in a Ca(2+)-dependent manner, dissociate the p53 tetramer, and inhibit its tumor suppressi ...

    Elevated levels of the tumor marker S100B are observed in malignant melanoma, and this EF-hand-containing protein was shown to directly bind wild-type (wt) p53 in a Ca(2+)-dependent manner, dissociate the p53 tetramer, and inhibit its tumor suppression functions. Likewise, inhibiting S100B with small interfering RNA (siRNA(S100B)) is sufficient to restore wild-type p53 levels and its downstream gene products and induce the arrest of cell growth and UV-dependent apoptosis in malignant melanoma. Therefore, it is a goal to develop S100B inhibitors (SBiXs) that inhibit the S100B-p53 complex and restore active p53 in this deadly cancer. Using a structure-activity relationship by nuclear magnetic resonance approach (SAR by NMR), three persistent binding pockets are found on S100B, termed sites 1-3. While inhibitors that simultaneously bind sites 2 and 3 are in place, no molecules that simultaneously bind all three persistent sites are available. For this purpose, Cys84 was used in this study as a potential means to bridge sites 1 and 2 because it is located in a small crevice between these two deeper pockets on the protein. Using a fluorescence polarization competition assay, several Cys84-modified S100B complexes were identified and examined further. For five such SBiX-S100B complexes, crystallographic structures confirmed their covalent binding to Cys84 near site 2 and thus present straightforward chemical biology strategies for bridging sites 1 and 3. Importantly, one such compound, SC1982, showed an S100B-dependent death response in assays with WM115 malignant melanoma cells, so it will be particularly useful for the design of SBiX molecules with improved affinity and specificity.


    Organizational Affiliation

    Center for Biomolecular Therapeutics (CBT), Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine , Baltimore, Maryland 21201, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein S100-B
X, A
92Bos taurusMutation(s): 0 
Gene Names: S100B
Find proteins for P02638 (Bos taurus)
Go to Gene View: S100B
Go to UniProtKB:  P02638
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NQS
Query on NQS

Download SDF File 
Download CCD File 
A, X
2-[(2-hydroxyethyl)sulfanyl]naphthalene-1,4-dione
C12 H10 O3 S
IBLOZMPODBITIK-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A, X
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.08 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.192 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 35.180α = 90.00
b = 56.270β = 108.79
c = 48.050γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
Blu-Icedata collection
Aimlessdata scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited StatesGM58888
National Institutes of Health/National Cancer InstituteUnited StatesCA107331
National Institutes of Health/National Cancer InstituteUnited StatesCA154274

Revision History 

  • Version 1.0: 2014-11-05
    Type: Initial release
  • Version 1.1: 2017-09-13
    Type: Author supporting evidence, Database references, Derived calculations, Other, Refinement description, Source and taxonomy
  • Version 1.2: 2017-11-22
    Type: Refinement description