View source for 6epn


==Ras guanine exchange factor SOS1 (Rem-cdc25) in complex with KRAS(G12C) and fragment screening hit F2==
<StructureSection load='6epn' size='340' side='right'caption='[[6epn]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6epn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6EPN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6EPN FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BQ2:1-(3,4-dihydro-1~{H}-isoquinolin-2-yl)-2-oxidanyl-ethanone'>BQ2</scene>, <scene name='pdbligand=DMS:DIMETHYL+SULFOXIDE'>DMS</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[6epl|6epl]], [[6epm|6epm]], [[6epo|6epo]], [[6epp|6epp]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KRAS, KRAS2, RASK2 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN]), SOS1 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</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=6epn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6epn OCA], [https://pdbe.org/6epn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6epn RCSB], [https://www.ebi.ac.uk/pdbsum/6epn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6epn ProSAT]</span></td></tr>
</table>
== Disease ==
[[https://www.uniprot.org/uniprot/RASK_HUMAN RASK_HUMAN]] Defects in KRAS are a cause of acute myelogenous leukemia (AML) [MIM:[https://omim.org/entry/601626 601626]]. AML is a malignant disease in which hematopoietic precursors are arrested in an early stage of development.<ref>PMID:8955068</ref>   Defects in KRAS are a cause of juvenile myelomonocytic leukemia (JMML) [MIM:[https://omim.org/entry/607785 607785]]. JMML is a pediatric myelodysplastic syndrome that constitutes approximately 30% of childhood cases of myelodysplastic syndrome (MDS) and 2% of leukemia. It is characterized by leukocytosis with tissue infiltration and in vitro hypersensitivity of myeloid progenitors to granulocyte-macrophage colony stimulating factor.  Defects in KRAS are the cause of Noonan syndrome type 3 (NS3) [MIM:[https://omim.org/entry/609942 609942]]. Noonan syndrome (NS) [MIM:[https://omim.org/entry/163950 163950]] is a disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS is associated with juvenile myelomonocytic leukemia (JMML). NS3 inheritance is autosomal dominant.<ref>PMID:16773572</ref> <ref>PMID:16474405</ref> <ref>PMID:17468812</ref> <ref>PMID:17056636</ref> <ref>PMID:19396835</ref> <ref>PMID:20949621</ref>   Defects in KRAS are a cause of gastric cancer (GASC) [MIM:[https://omim.org/entry/613659 613659]]; also called gastric cancer intestinal or stomach cancer. Gastric cancer is a malignant disease which starts in the stomach, can spread to the esophagus or the small intestine, and can extend through the stomach wall to nearby lymph nodes and organs. It also can metastasize to other parts of the body. The term gastric cancer or gastric carcinoma refers to adenocarcinoma of the stomach that accounts for most of all gastric malignant tumors. Two main histologic types are recognized, diffuse type and intestinal type carcinomas. Diffuse tumors are poorly differentiated infiltrating lesions, resulting in thickening of the stomach. In contrast, intestinal tumors are usually exophytic, often ulcerating, and associated with intestinal metaplasia of the stomach, most often observed in sporadic disease.<ref>PMID:3034404</ref> <ref>PMID:7773929</ref> <ref>PMID:14534542</ref>   Note=Defects in KRAS are a cause of pylocytic astrocytoma (PA). Pylocytic astrocytomas are neoplasms of the brain and spinal cord derived from glial cells which vary from histologically benign forms to highly anaplastic and malignant tumors.<ref>PMID:8439212</ref>   Defects in KRAS are a cause of cardiofaciocutaneous syndrome (CFC syndrome) [MIM:[https://omim.org/entry/115150 115150]]; also known as cardio-facio-cutaneous syndrome. CFC syndrome is characterized by a distinctive facial appearance, heart defects and mental retardation. Heart defects include pulmonic stenosis, atrial septal defects and hypertrophic cardiomyopathy. Some affected individuals present with ectodermal abnormalities such as sparse, friable hair, hyperkeratotic skin lesions and a generalized ichthyosis-like condition. Typical facial features are similar to Noonan syndrome. They include high forehead with bitemporal constriction, hypoplastic supraorbital ridges, downslanting palpebral fissures, a depressed nasal bridge, and posteriorly angulated ears with prominent helices. The inheritance of CFC syndrome is autosomal dominant.  Note=KRAS mutations are involved in cancer development. [[https://www.uniprot.org/uniprot/SOS1_HUMAN SOS1_HUMAN]] Defects in SOS1 are the cause of gingival fibromatosis 1 (GGF1) [MIM:[https://omim.org/entry/135300 135300]]; also known as GINGF1. Gingival fibromatosis is a rare overgrowth condition characterized by a benign, slowly progressive, nonhemorrhagic, fibrous enlargement of maxillary and mandibular keratinized gingiva. GGF1 is usually transmitted as an autosomal dominant trait, although sporadic cases are common.<ref>PMID:11868160</ref>   Defects in SOS1 are the cause of Noonan syndrome type 4 (NS4) [MIM:[https://omim.org/entry/610733 610733]]. NS4 is an autosomal dominant disorder characterized by dysmorphic facial features, short stature, hypertelorism, cardiac anomalies, deafness, motor delay, and a bleeding diathesis. It is a genetically heterogeneous and relatively common syndrome, with an estimated incidence of 1 in 1000-2500 live births. Rarely, NS4 is associated with juvenile myelomonocytic leukemia (JMML). SOS1 mutations engender a high prevalence of pulmonary valve disease; atrial septal defects are less common.<ref>PMID:17143285</ref> <ref>PMID:17143282</ref> <ref>PMID:19020799</ref> <ref>PMID:19438935</ref> <ref>PMID:20683980</ref> <ref>PMID:20673819</ref> <ref>PMID:19953625</ref> <ref>PMID:21387466</ref>  
== Function ==
[[https://www.uniprot.org/uniprot/RASK_HUMAN RASK_HUMAN]] Ras proteins bind GDP/GTP and possess intrinsic GTPase activity. [[https://www.uniprot.org/uniprot/SOS1_HUMAN SOS1_HUMAN]] Promotes the exchange of Ras-bound GDP by GTP. 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Since the late 1980s, mutations in the RAS genes have been recognized as major oncogenes with a high occurrence rate in human cancers. Such mutations reduce the ability of the small GTPase RAS to hydrolyze GTP, keeping this molecular switch in a constitutively active GTP-bound form that drives, unchecked, oncogenic downstream signaling. One strategy to reduce the levels of active RAS is to target guanine nucleotide exchange factors, which allow RAS to cycle from the inactive GDP-bound state to the active GTP-bound form. Here, we describe the identification of potent and cell-active small-molecule inhibitors which efficiently disrupt the interaction between KRAS and its exchange factor SOS1, a mode of action confirmed by a series of biophysical techniques. The binding sites, mode of action, and selectivity were elucidated using crystal structures of KRAS(G12C)-SOS1, SOS1, and SOS2. By preventing formation of the KRAS-SOS1 complex, these inhibitors block reloading of KRAS with GTP, leading to antiproliferative activity. The final compound 23 (BAY-293) selectively inhibits the KRAS-SOS1 interaction with an IC50 of 21 nM and is a valuable chemical probe for future investigations.

Discovery of potent SOS1 inhibitors that block RAS activation via disruption of the RAS-SOS1 interaction.,Hillig RC, Sautier B, Schroeder J, Moosmayer D, Hilpmann A, Stegmann CM, Werbeck ND, Briem H, Boemer U, Weiske J, Badock V, Mastouri J, Petersen K, Siemeister G, Kahmann JD, Wegener D, Bohnke N, Eis K, Graham K, Wortmann L, von Nussbaum F, Bader B Proc Natl Acad Sci U S A. 2019 Feb 12;116(7):2551-2560. doi:, 10.1073/pnas.1812963116. Epub 2019 Jan 25. PMID:30683722<ref>PMID:30683722</ref>

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

==See Also==
*[[GTPase KRas 3D structures|GTPase KRas 3D structures]]
*[[Son of sevenless|Son of sevenless]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Bader, B]]
[[Category: Badock, V]]
[[Category: Briem, H]]
[[Category: Hillig, R C]]
[[Category: Hilpmann, A]]
[[Category: Kahmann, J]]
[[Category: Moosmayer, D]]
[[Category: Petersen, K]]
[[Category: Sautier, B]]
[[Category: Schroeder, J]]
[[Category: Wegener, D]]
[[Category: Wortmann, L]]
[[Category: Fragment screen]]
[[Category: Gef]]
[[Category: Gtpase]]
[[Category: Guanine nucleotide exchange factor]]
[[Category: Signaling protein]]