View source for 6amb


==Crystal Structure of the Afadin RA1 domain in complex with HRAS==
<StructureSection load='6amb' size='340' side='right'caption='[[6amb]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6amb]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] 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=6AMB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6AMB 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GNP:PHOSPHOAMINOPHOSPHONIC+ACID-GUANYLATE+ESTER'>GNP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=6amb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6amb OCA], [https://pdbe.org/6amb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6amb RCSB], [https://www.ebi.ac.uk/pdbsum/6amb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6amb ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/RASH_HUMAN RASH_HUMAN] Defects in HRAS are the cause of faciocutaneoskeletal syndrome (FCSS) [MIM:[https://omim.org/entry/218040 218040]. A rare condition characterized by prenatally increased growth, postnatal growth deficiency, mental retardation, distinctive facial appearance, cardiovascular abnormalities (typically pulmonic stenosis, hypertrophic cardiomyopathy and/or atrial tachycardia), tumor predisposition, skin and musculoskeletal abnormalities.<ref>PMID:16170316</ref> <ref>PMID:16329078</ref> <ref>PMID:16443854</ref> <ref>PMID:17054105</ref> <ref>PMID:18247425</ref> <ref>PMID:18039947</ref> <ref>PMID:19995790</ref>   Defects in HRAS are the cause of congenital myopathy with excess of muscle spindles (CMEMS) [MIM:[https://omim.org/entry/218040 218040]. CMEMS is a variant of Costello syndrome.<ref>PMID:17412879</ref>   Defects in HRAS may be a cause of susceptibility to Hurthle cell thyroid carcinoma (HCTC) [MIM:[https://omim.org/entry/607464 607464]. Hurthle cell thyroid carcinoma accounts for approximately 3% of all thyroid cancers. Although they are classified as variants of follicular neoplasms, they are more often multifocal and somewhat more aggressive and are less likely to take up iodine than are other follicular neoplasms.  Note=Mutations which change positions 12, 13 or 61 activate the potential of HRAS to transform cultured cells and are implicated in a variety of human tumors.  Defects in HRAS are a cause of susceptibility to bladder cancer (BLC) [MIM:[https://omim.org/entry/109800 109800]. A malignancy originating in tissues of the urinary bladder. It often presents with multiple tumors appearing at different times and at different sites in the bladder. Most bladder cancers are transitional cell carcinomas. They begin in cells that normally make up the inner lining of the bladder. Other types of bladder cancer include squamous cell carcinoma (cancer that begins in thin, flat cells) and adenocarcinoma (cancer that begins in cells that make and release mucus and other fluids). Bladder cancer is a complex disorder with both genetic and environmental influences.  Note=Defects in HRAS are the cause of oral squamous cell carcinoma (OSCC).<ref>PMID:1459726</ref>   Defects in HRAS are the cause of Schimmelpenning-Feuerstein-Mims syndrome (SFM) [MIM:[https://omim.org/entry/163200 163200]. A disease characterized by sebaceous nevi, often on the face, associated with variable ipsilateral abnormalities of the central nervous system, ocular anomalies, and skeletal defects. Many oral manifestations have been reported, not only including hypoplastic and malformed teeth, and mucosal papillomatosis, but also ankyloglossia, hemihyperplastic tongue, intraoral nevus, giant cell granuloma, ameloblastoma, bone cysts, follicular cysts, oligodontia, and odontodysplasia. Sebaceous nevi follow the lines of Blaschko and these can continue as linear intraoral lesions, as in mucosal papillomatosis.<ref>PMID:22683711</ref> 
== Function ==
[https://www.uniprot.org/uniprot/RASH_HUMAN RASH_HUMAN] Ras proteins bind GDP/GTP and possess intrinsic GTPase activity.<ref>PMID:14500341</ref> <ref>PMID:9020151</ref> <ref>PMID:12740440</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Elucidation of activation mechanisms governing protein fusions is essential for therapeutic development. MLL undergoes rearrangement with numerous partners, including a recurrent translocation fusing the epigenetic regulator to a cytoplasmic RAS effector, AF6/afadin. We show here that AF6 employs a non-canonical, evolutionarily conserved alpha-helix to bind RAS, unique to AF6 and the classical RASSF effectors. Further, all patients with MLL-AF6 translocations express fusion proteins missing only this helix from AF6, resulting in exposure of hydrophobic residues that induce dimerization. We provide evidence that oligomerization is the dominant mechanism driving oncogenesis from rare MLL translocation partners and employ our mechanistic understanding of MLL-AF6 to examine how dimers induce leukemia. Proteomic data resolve association of dimerized MLL with gene expression modulators, and inhibiting dimerization disrupts formation of these complexes while completely abrogating leukemogenesis in mice. Oncogenic gene translocations are thus selected under pressure from protein structure/function, underscoring the complex nature of chromosomal rearrangements.

Evolution of AF6-RAS association and its implications in mixed-lineage leukemia.,Smith MJ, Ottoni E, Ishiyama N, Goudreault M, Haman A, Meyer C, Tucholska M, Gasmi-Seabrook G, Menezes S, Laister RC, Minden MD, Marschalek R, Gingras AC, Hoang T, Ikura M Nat Commun. 2017 Oct 23;8(1):1099. doi: 10.1038/s41467-017-01326-5. PMID:29062045<ref>PMID:29062045</ref>

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

==See Also==
*[[GTPase Hras 3D structures|GTPase Hras 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Ikura M]]
[[Category: Ishiyama N]]
[[Category: Smith MJ]]