View source for 6h46


==Human KRAS in complex with darpin K13==
<StructureSection load='6h46' size='340' side='right'caption='[[6h46]], [[Resolution|resolution]] 2.22&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6h46]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6H46 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6H46 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KRAS, KRAS2, RASK2 ([http://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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6h46 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6h46 OCA], [http://pdbe.org/6h46 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6h46 RCSB], [http://www.ebi.ac.uk/pdbsum/6h46 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6h46 ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/RASK_HUMAN RASK_HUMAN]] Defects in KRAS are a cause of acute myelogenous leukemia (AML) [MIM:[http://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:[http://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:[http://omim.org/entry/609942 609942]]. Noonan syndrome (NS) [MIM:[http://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:[http://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:[http://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 ==
[[http://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 ==
Inhibiting the RAS oncogenic protein has largely been through targeting the switch regions that interact with signalling effector proteins. Here, we report designed ankyrin repeat proteins (DARPins) macromolecules that specifically inhibit the KRAS isoform by binding to an allosteric site encompassing the region around KRAS-specific residue histidine 95 at the helix alpha3/loop 7/helix alpha4 interface. We show that these DARPins specifically inhibit KRAS/effector interactions and the dependent downstream signalling pathways in cancer cells. Binding by the DARPins at that region influences KRAS/effector interactions in different ways, including KRAS nucleotide exchange and inhibiting KRAS dimerization at the plasma membrane. These results highlight the importance of targeting the alpha3/loop 7/alpha4 interface, a previously untargeted site in RAS, for specifically inhibiting KRAS function.

KRAS-specific inhibition using a DARPin binding to a site in the allosteric lobe.,Bery N, Legg S, Debreczeni J, Breed J, Embrey K, Stubbs C, Kolasinska-Zwierz P, Barrett N, Marwood R, Watson J, Tart J, Overman R, Miller A, Phillips C, Minter R, Rabbitts TH Nat Commun. 2019 Jun 13;10(1):2607. doi: 10.1038/s41467-019-10419-2. PMID:31197133<ref>PMID:31197133</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6h46" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Barrett, N]]
[[Category: Bery, N]]
[[Category: Breed, J]]
[[Category: Debreczeni, J E]]
[[Category: Embrey, K]]
[[Category: Kolasinska-Zwierz, P]]
[[Category: Legg, S]]
[[Category: Marwood, R]]
[[Category: Miller, A]]
[[Category: Minter, R]]
[[Category: Overman, R]]
[[Category: Phillips, C]]
[[Category: Rabbitts, T H]]
[[Category: Stubbs, C]]
[[Category: Tart, J]]
[[Category: Watson, J]]
[[Category: Darpin]]
[[Category: Gtp-ase]]
[[Category: Kras signalling]]
[[Category: Signaling protein]]