View source for 4krp


==Nanobody/VHH domain 9G8 in complex with the extracellular region of EGFR==
<StructureSection load='4krp' size='340' side='right'caption='[[4krp]], [[Resolution|resolution]] 2.82&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4krp]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens], [https://en.wikipedia.org/wiki/Lama_glama Lama glama] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4KRP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4KRP 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]] 2.823&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=4krp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4krp OCA], [https://pdbe.org/4krp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4krp RCSB], [https://www.ebi.ac.uk/pdbsum/4krp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4krp ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/EGFR_HUMAN EGFR_HUMAN] Defects in EGFR are associated with lung cancer (LNCR) [MIM:[https://omim.org/entry/211980 211980]. LNCR is a common malignancy affecting tissues of the lung. The most common form of lung cancer is non-small cell lung cancer (NSCLC) that can be divided into 3 major histologic subtypes: squamous cell carcinoma, adenocarcinoma, and large cell lung cancer. NSCLC is often diagnosed at an advanced stage and has a poor prognosis.
== Function ==
[https://www.uniprot.org/uniprot/EGFR_HUMAN EGFR_HUMAN] Receptor tyrosine kinase binding ligands of the EGF family and activating several signaling cascades to convert extracellular cues into appropriate cellular responses. Known ligands include EGF, TGFA/TGF-alpha, amphiregulin, epigen/EPGN, BTC/betacellulin, epiregulin/EREG and HBEGF/heparin-binding EGF. Ligand binding triggers receptor homo- and/or heterodimerization and autophosphorylation on key cytoplasmic residues. The phosphorylated receptor recruits adapter proteins like GRB2 which in turn activates complex downstream signaling cascades. Activates at least 4 major downstream signaling cascades including the RAS-RAF-MEK-ERK, PI3 kinase-AKT, PLCgamma-PKC and STATs modules. May also activate the NF-kappa-B signaling cascade. Also directly phosphorylates other proteins like RGS16, activating its GTPase activity and probably coupling the EGF receptor signaling to the G protein-coupled receptor signaling. Also phosphorylates MUC1 and increases its interaction with SRC and CTNNB1/beta-catenin.<ref>PMID:7657591</ref> <ref>PMID:11602604</ref> <ref>PMID:12873986</ref> <ref>PMID:10805725</ref> <ref>PMID:11116146</ref> <ref>PMID:11483589</ref> <ref>PMID:17115032</ref> <ref>PMID:21258366</ref> <ref>PMID:12297050</ref> <ref>PMID:12620237</ref> <ref>PMID:15374980</ref> <ref>PMID:19560417</ref> <ref>PMID:20837704</ref>   Isoform 2 may act as an antagonist of EGF action.<ref>PMID:7657591</ref> <ref>PMID:11602604</ref> <ref>PMID:12873986</ref> <ref>PMID:10805725</ref> <ref>PMID:11116146</ref> <ref>PMID:11483589</ref> <ref>PMID:17115032</ref> <ref>PMID:21258366</ref> <ref>PMID:12297050</ref> <ref>PMID:12620237</ref> <ref>PMID:15374980</ref> <ref>PMID:19560417</ref> <ref>PMID:20837704</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The epidermal growth factor receptor (EGFR) is implicated in human cancers and is the target of several classes of therapeutic agents, including antibody-based drugs. Here, we describe X-ray crystal structures of the extracellular region of EGFR in complex with three inhibitory nanobodies, the variable domains of heavy chain only antibodies (VHH). VHH domains, the smallest natural antigen-binding modules, are readily engineered for diagnostic and therapeutic applications. All three VHH domains prevent ligand-induced EGFR activation, but use two distinct mechanisms. 7D12 sterically blocks ligand binding to EGFR in a manner similar to that of cetuximab. EgA1 and 9G8 bind an epitope near the EGFR domain II/III junction, preventing receptor conformational changes required for high-affinity ligand binding and dimerization. This epitope is accessible to the convex VHH paratope but inaccessible to the flatter paratope of monoclonal antibodies. Appreciating the modes of binding and inhibition of these VHH domains will aid in developing them for tumor imaging and/or cancer therapy.

Structural evaluation of EGFR inhibition mechanisms for nanobodies/VHH domains.,Schmitz KR, Bagchi A, Roovers RC, van Bergen en Henegouwen PM, Ferguson KM Structure. 2013 Jul 2;21(7):1214-24. doi: 10.1016/j.str.2013.05.008. Epub 2013, Jun 20. PMID:23791944<ref>PMID:23791944</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4krp" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
*[[Epidermal growth factor receptor 3D structures|Epidermal growth factor receptor 3D structures]]
*[[3D structures of non-human antibody|3D structures of non-human antibody]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Lama glama]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Ferguson KM]]
[[Category: Schmitz KR]]