View source for 8vgq


==CryoEM structure of GNE-1952-alkylated KRAS G12C in complex with engineered conformationally rigid Fab 2H11.4DS==
<StructureSection load='8vgq' size='340' side='right'caption='[[8vgq]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8vgq]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8VGQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8VGQ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=A1AAW:1-[4-[6-methyl-7-(5-methyl-2~{H}-indazol-4-yl)quinazolin-4-yl]piperazin-1-yl]propan-1-one'>A1AAW</scene>, <scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</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=8vgq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8vgq OCA], [https://pdbe.org/8vgq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8vgq RCSB], [https://www.ebi.ac.uk/pdbsum/8vgq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8vgq 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 ==
High-resolution structures of proteins are critical to understanding molecular mechanisms of biological processes and in the discovery of therapeutic molecules. Cryo-EM has revolutionized structure determination of large proteins and their complexes(1), but a vast majority of proteins that underlie human diseases are small (&lt; 50 kDa) and usually beyond its reach due to low signal-to-noise images and difficulties in particle alignment(2). Current strategies to overcome this problem increase the overall size of small protein targets using scaffold proteins that bind to the target, but are limited by inherent flexibility and not being bound to their targets in a rigid manner, resulting in the target being poorly resolved compared to the scaffolds(3-11). Here we present an iteratively engineered molecular design for transforming Fabs (antibody fragments), into conformationally rigid scaffolds (Rigid-Fabs) that, when bound to small proteins (~20 kDa), can enable high-resolution structure determination using cryo-EM. This design introduces multiple disulfide bonds at strategic locations, generates a well-folded Fab constrained into a rigid conformation and can be applied to Fabs from various species, isotypes and chimeric Fabs. We present examples of the Rigid Fab design enabling high-resolution (2.3-2.5 A) structures of small proteins, Ang2 (26 kDa) and KRAS (21 kDa) by cryo-EM. The strategies for designing disulfide constrained Rigid Fabs in our work thus establish a general approach to overcome the target size limitation of single particle cryo-EM.

Disulfi de constrained Fabs overcome target size limitation for high-resolution single-particle cryo-EM.,Kung JE, Johnson MC, Jao CC, Arthur CP, Tegunov D, Rohou A, Sudhamsu J bioRxiv [Preprint]. 2024 May 13:2024.05.10.593593. doi: , 10.1101/2024.05.10.593593. PMID:38798381<ref>PMID:38798381</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8vgq" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Kung JE]]
[[Category: Sudhamsu J]]