3CZT

Crystal Structure of S100B in the Calcium and Zinc Loaded State at pH 9


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.162 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The crystal structures of human S100B in the zinc- and calcium-loaded state at three pH values reveal zinc ligand swapping.

Ostendorp, T.Diez, J.Heizmann, C.W.Fritz, G.

(2011) Biochim.Biophys.Acta 1813: 1083-1091

  • DOI: 10.1016/j.bbamcr.2010.10.006
  • Primary Citation of Related Structures:  3D0Y, 3D10

  • PubMed Abstract: 
  • S100B is a homodimeric zinc-, copper-, and calcium-binding protein of the family of EF-hand S100 proteins. Zn(2+) binding to S100B increases its affinity towards Ca(2+) as well as towards target peptides and proteins. Cu(2+) and Zn(2+) bind presumabl ...

    S100B is a homodimeric zinc-, copper-, and calcium-binding protein of the family of EF-hand S100 proteins. Zn(2+) binding to S100B increases its affinity towards Ca(2+) as well as towards target peptides and proteins. Cu(2+) and Zn(2+) bind presumably to the same site in S100B. We determined the structures of human Zn(2+)- and Ca(2+)-loaded S100B at pH 6.5, pH 9, and pH 10 by X-ray crystallography at 1.5, 1.4, and 1.65Ã… resolution, respectively. Two Zn(2+) ions are coordinated tetrahedrally at the dimer interface by His and Glu residues from both subunits. The crystal structures revealed that ligand swapping occurs for one of the four ligands in the Zn(2+)-binding sites. Whereas at pH 9, the Zn(2+) ions are coordinated by His15, His25, His 85', and His 90', at pH 6.5 and pH 10, His90' is replaced by Glu89'. The results document that the Zn(2+)-binding sites are flexible to accommodate other metal ions such as Cu(2+). Moreover, we characterized the structural changes upon Zn(2+) binding, which might lead to increased affinity towards Ca(2+) as well as towards target proteins. We observed that in Zn(2+)-Ca(2+)-loaded S100B the C-termini of helix IV adopt a distinct conformation. Zn(2+) binding induces a repositioning of residues Phe87 and Phe88, which are involved in target protein binding. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.


    Organizational Affiliation

    Fachbereich Biologie, Mathematisch-Naturwissenschaftliche Sektion, Universität Konstanz, 78459 Konstanz, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein S100-B
X
92Homo sapiensGene Names: S100B
Find proteins for P04271 (Homo sapiens)
Go to Gene View: S100B
Go to UniProtKB:  P04271
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
X
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.4 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.162 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 34.980α = 90.00
b = 89.260β = 90.00
c = 59.580γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
XDSdata reduction
MOLREPphasing
REFMACrefinement
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-04-14
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description