View source for 6yr8


==Affimer K6 - KRAS protein complex==
<StructureSection load='6yr8' size='340' side='right'caption='[[6yr8]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6yr8]] 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=6YR8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6YR8 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></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])</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=6yr8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6yr8 OCA], [https://pdbe.org/6yr8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6yr8 RCSB], [https://www.ebi.ac.uk/pdbsum/6yr8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6yr8 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. 
== Function ==
[[https://www.uniprot.org/uniprot/RASK_HUMAN RASK_HUMAN]] Ras proteins bind GDP/GTP and possess intrinsic GTPase activity. 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RAS mutations are the most common oncogenic drivers across human cancers, but there remains a paucity of clinically-validated pharmacological inhibitors of RAS, as druggable pockets have proven difficult to identify. Here, we identify two RAS-binding Affimer proteins, K3 and K6, that inhibit nucleotide exchange and downstream signaling pathways with distinct isoform and mutant profiles. Affimer K6 binds in the SI/SII pocket, whilst Affimer K3 is a non-covalent inhibitor of the SII region that reveals a conformer of wild-type RAS with a large, druggable SII/alpha3 pocket. Competitive NanoBRET between the RAS-binding Affimers and known RAS binding small-molecules demonstrates the potential to use Affimers as tools to identify pharmacophores. This work highlights the potential of using biologics with small interface surfaces to select unseen, druggable conformations in conjunction with pharmacophore identification for hard-to-drug proteins.

RAS-inhibiting biologics identify and probe druggable pockets including an SII-alpha3 allosteric site.,Haza KZ, Martin HL, Rao A, Turner AL, Saunders SE, Petersen B, Tiede C, Tipping K, Tang AA, Ajayi M, Taylor T, Harvey M, Fishwick KM, Adams TL, Gaule TG, Trinh CH, Johnson M, Breeze AL, Edwards TA, McPherson MJ, Tomlinson DC Nat Commun. 2021 Jun 30;12(1):4045. doi: 10.1038/s41467-021-24316-0. PMID:34193876<ref>PMID:34193876</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6yr8" style="background-color:#fffaf0;"></div>

==See Also==
*[[GTPase KRas 3D structures|GTPase KRas 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Edwards, T A]]
[[Category: Haza, K Z]]
[[Category: Martin, H L]]
[[Category: McPherson, M J]]
[[Category: Rao, A]]
[[Category: Tiede, C]]
[[Category: Tomlinson, D C]]
[[Category: Trinh, C H]]
[[Category: Affimer]]
[[Category: Inhibitor]]
[[Category: Kra]]
[[Category: Protein binding]]
[[Category: Protein complex]]