View source for 1ywt


==Crystal structure of the human sigma isoform of 14-3-3 in complex with a mode-1 phosphopeptide==
<StructureSection load='1ywt' size='340' side='right'caption='[[1ywt]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ywt]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YWT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1YWT 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SEP:PHOSPHOSERINE'>SEP</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=1ywt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ywt OCA], [https://pdbe.org/1ywt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ywt RCSB], [https://www.ebi.ac.uk/pdbsum/1ywt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ywt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/1433S_HUMAN 1433S_HUMAN] Adapter protein implicated in the regulation of a large spectrum of both general and specialized signaling pathways. Binds to a large number of partners, usually by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner. When bound to KRT17, regulates protein synthesis and epithelial cell growth by stimulating Akt/mTOR pathway (By similarity).  p53-regulated inhibitor of G2/M progression.
== 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/yw/1ywt_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1ywt ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 14-3-3 family of proteins includes seven isotypes in mammalian cells that play numerous diverse roles in intracellular signaling. Most 14-3-3 proteins form homodimers and mixed heterodimers between different isotypes, with overlapping roles in ligand binding. In contrast, one mammalian isoform, 14-3-3sigma, expressed primarily in epithelial cells, appears to play a unique role in the cellular response to DNA damage and in human oncogenesis. The biological and structural basis for these 14-3-3sigma-specific functions is unknown. We demonstrate that endogenous 14-3-3sigma preferentially forms homodimers in cells. We have solved the x-ray crystal structure of 14-3-3sigma bound to an optimal phosphopeptide ligand at 2.4 angstroms resolution. The structure reveals the presence of stabilizing ring-ring and salt bridge interactions unique to the 14-3-3sigma homodimer structure and potentially destabilizing electrostatic interactions between subunits in 14-3-3sigma-containing heterodimers, rationalizing preferential homodimerization of 14-3-3sigma in vivo. The interaction of the phosphopeptide with 14-3-3 reveals a conserved mechanism for phospho-dependent ligand binding, implying that the phosphopeptide binding cleft is not the critical determinant of the unique biological properties of 14-3-3sigma. Instead, the structure suggests a second ligand binding site involved in 14-3-3sigma-specific ligand discrimination. We have confirmed this by site-directed mutagenesis of three sigma-specific residues that uniquely define this site. Mutation of these residues to the alternative sequence that is absolutely conserved in all other 14-3-3 isotypes confers upon 14-3-3sigma the ability to bind to Cdc25C, a ligand that is known to bind to other 14-3-3 proteins but not to sigma.

A structural basis for 14-3-3sigma functional specificity.,Wilker EW, Grant RA, Artim SC, Yaffe MB J Biol Chem. 2005 May 13;280(19):18891-8. Epub 2005 Feb 24. PMID:15731107<ref>PMID:15731107</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ywt" style="background-color:#fffaf0;"></div>

==See Also==
*[[14-3-3 protein 3D structures|14-3-3 protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Artim SC]]
[[Category: Grant RA]]
[[Category: Wilker EW]]
[[Category: Yaffe MB]]