View source for 6wo2


==Crystal Structure of the Grb2 SH2 Domain in Complex with a Tripeptide: Ac-pY-Ac6c-N-isohexyl==
<StructureSection load='6wo2' size='340' side='right'caption='[[6wo2]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6wo2]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6WO2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6WO2 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&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=02K:1-AMINOCYCLOHEXANECARBOXYLIC+ACID'>02K</scene>, <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=IPA:ISOPROPYL+ALCOHOL'>IPA</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=PTR:O-PHOSPHOTYROSINE'>PTR</scene>, <scene name='pdbligand=U67:4-methylpentan-1-amine'>U67</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=6wo2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6wo2 OCA], [https://pdbe.org/6wo2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6wo2 RCSB], [https://www.ebi.ac.uk/pdbsum/6wo2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6wo2 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GRB2_HUMAN GRB2_HUMAN] Adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway.<ref>PMID:1322798</ref> <ref>PMID:8178156</ref> <ref>PMID:19815557</ref>   Isoform 2 does not bind to phosphorylated epidermal growth factor receptor (EGFR) but inhibits EGF-induced transactivation of a RAS-responsive element. Isoform 2 acts as a dominant negative protein over GRB2 and by suppressing proliferative signals, may trigger active programmed cell death.<ref>PMID:1322798</ref> <ref>PMID:8178156</ref> <ref>PMID:19815557</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Understanding how making structural changes in small molecules affects their binding affinities for targeted proteins is central to improving strategies for rational drug design. To assess the effects of varying the nature of nonpolar groups upon binding entropies and enthalpies, we designed and prepared a set of Grb2-SH2 domain ligands, Ac-pTyr-Ac6c-Asn-(CH2)n-R, in which the size and electrostatic nature of R groups at the pTyr+3 site were varied. The complexes of these ligands with the Grb2-SH2 domain were evaluated in a series of studies in which the binding thermodynamics were determined using isothermal titration calorimetry, and binding interactions were examined in crystallographic studies of two different complexes. Notably, adding nonpolar groups to the pTyr+3 site leads to higher binding affinities, but the magnitude and energetic origins of these effects vary with the nature of the R substituent. For example, enhancements to binding affinities using aliphatic R groups are driven by more favorable changes in binding entropies, whereas aryl R groups improve binding free energies through a combination of more favorable changes in binding enthalpies and entropies. However, enthalpy/entropy compensation plays a significant role in these associations and mitigates against any significant variation in binding free energies, which vary by only 0.8 kcal*mol(-1), with changes in the electrostatic nature and size of the R group. Crystallographic studies show that differences in DeltaG degrees or DeltaH degrees correlate with buried nonpolar surface area, but they do not correlate with the total number of polar or van der Waals contacts. The relative number of ordered water molecules and relative order in the side chains at pTyr+3 correlate with differences in -TDeltaS degrees . Overall, these studies show that burial of nonpolar surface can lead to enhanced binding affinities arising from dominating entropy- or enthalpy-driven hydrophobic effects, depending upon the electrostatic nature of the apolar R group.

Some thermodynamic effects of varying nonpolar surfaces in protein-ligand interactions.,Cramer DL, Cheng B, Tian J, Clements JH, Wypych RM, Martin SF Eur J Med Chem. 2020 Aug 23;208:112771. doi: 10.1016/j.ejmech.2020.112771. PMID:32916312<ref>PMID:32916312</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6wo2" style="background-color:#fffaf0;"></div>

==See Also==
*[[Growth factor receptor-bound proteins 3D structures|Growth factor receptor-bound proteins 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Clements JH]]
[[Category: Martin SF]]