View source for 3gk4


==X-ray structure of bovine SBi523,Ca(2+)-S100B==
<StructureSection load='3gk4' size='340' side='right'caption='[[3gk4]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3gk4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3GK4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3GK4 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=53A:ETHYL+5-{[(1R)-1-(ETHOXYCARBONYL)-2-OXOPROPYL]SULFANYL}-1,2-DIHYDRO[1,2,3]TRIAZOLO[1,5-A]QUINAZOLINE-3-CARBOXYLATE'>53A</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3gk4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3gk4 OCA], [https://pdbe.org/3gk4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3gk4 RCSB], [https://www.ebi.ac.uk/pdbsum/3gk4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3gk4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/S100B_BOVIN S100B_BOVIN] Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer. Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites. Binds to and initiates the activation of STK38 by releasing autoinhibitory intramolecular interactions within the kinase. Interaction with AGER after myocardial infarction may play a role in myocyte apoptosis by activating ERK1/2 and p53/TP53 signaling. Could assist ATAD3A cytoplasmic processing, preventing aggregation and favoring mitochondrial localization (By similarity).<ref>PMID:14661952</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/gk/3gk4_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3gk4 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Structural studies are part of a rational drug design program underway to inhibit the S100B-p53 interaction and restore wild-type p53 function in malignant melanoma. To this end, structures of three compounds (SBi132, SBi1279, and SBi523) bound to Ca&lt;sup&gt;2+&lt;/sup&gt;-S100B were determined by X-ray crystallography at 2.10 A (Rfree = 0.257), 1.98 A (Rfree = 0.281) and 1.90 A (Rfree = 0.228) resolution, respectively. Upon comparison, SBi132, SBi279, and SBi523 were found to bind in distinct locations/orientations within the hydrophobic target binding pocket of Ca&lt;sup&gt;2+&lt;/sup&gt;-S100B with minimal structural changes observed for the protein upon complex formation with each compound. Specifically, SBi132 binds nearby residues in loop 2 (His-42, Phe-43, Leu-44) and helix 4 (Phe-76, Met-79, Ile-80, Ala-83, Cys-84, Phe-87 and Phe-88); whereas, SBi523 interacts with a separate site defined by residues within loop 2 (Ser-41, His-42, Phe-43, Leu-44, Glu-45 and Glu-46) and one residue on helix 4 (Phe-87). The SBi279 binding site on Ca&lt;sup&gt;2+&lt;/sup&gt;-S100B overlaps the SBi132 and SBi523 sites and contacts residues in both loop 2 (Ser-41, His-42, Phe-43, Leu-44, Glu-45) and helix 4 (Ile-80, Ala-83, Cys-84, Phe-87 and Phe-88). NMR data, including saturation transfer difference (STD) and &lt;sup&gt;15&lt;/sup&gt;N backbone and &lt;sup&gt;13&lt;/sup&gt;C sidechain chemical shift perturbations were consistent with the X-ray crystal structures and demonstrated the relevance of all three small molecule-S100B complexes in solution. The discovery that SBi132, SBi279, and SBi523 bind to proximal sites on Ca&lt;sup&gt;2+&lt;/sup&gt;-S100B could be useful for the development of a new class of molecule(s) that interacts with one or more of these binding sites simultaneously, thereby by yielding novel tight binding inhibitors specific for blocking protein-protein interactions involving S100B.

Small molecules bound to unique sites in the target protein binding cleft of calcium-bound S100B as characterized by nuclear magnetic resonance (NMR) and X-ray crystallography.,Charpentier TH, Wilder PT, Liriano MA, Varney KM, Zhong S, Coop A, Pozharski E, Mackerell AD, Toth EA, Weber DJ Biochemistry. 2009 May 26. PMID:19469484<ref>PMID:19469484</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3gk4" style="background-color:#fffaf0;"></div>

==See Also==
*[[S100 proteins 3D structures|S100 proteins 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Charpentier TH]]
[[Category: Toth EA]]
[[Category: Weber DJ]]