View source for 6oqm


==crystal structure of the MSH6 PWWP domain==
<StructureSection load='6oqm' size='340' side='right'caption='[[6oqm]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6oqm]] is a 1 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=6OQM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6OQM 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=UNX:UNKNOWN+ATOM+OR+ION'>UNX</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=6oqm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6oqm OCA], [https://pdbe.org/6oqm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6oqm RCSB], [https://www.ebi.ac.uk/pdbsum/6oqm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6oqm ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/MSH6_HUMAN MSH6_HUMAN] Defects in MSH6 are the cause of hereditary non-polyposis colorectal cancer type 5 (HNPCC5) [MIM:[https://omim.org/entry/614350 614350]. Mutations in more than one gene locus can be involved alone or in combination in the production of the HNPCC phenotype (also called Lynch syndrome). Most families with clinically recognized HNPCC have mutations in either MLH1 or MSH2 genes. HNPCC is an autosomal, dominantly inherited disease associated with marked increase in cancer susceptibility. It is characterized by a familial predisposition to early onset colorectal carcinoma (CRC) and extra-colonic cancers of the gastrointestinal, urological and female reproductive tracts. HNPCC is reported to be the most common form of inherited colorectal cancer in the Western world. Cancers in HNPCC originate within benign neoplastic polyps termed adenomas. Clinically, HNPCC is often divided into two subgroups. Type I: hereditary predisposition to colorectal cancer, a young age of onset, and carcinoma observed in the proximal colon. Type II: patients have an increased risk for cancers in certain tissues such as the uterus, ovary, breast, stomach, small intestine, skin, and larynx in addition to the colon. Diagnosis of classical HNPCC is based on the Amsterdam criteria: 3 or more relatives affected by colorectal cancer, one a first degree relative of the other two; 2 or more generation affected; 1 or more colorectal cancers presenting before 50 years of age; exclusion of hereditary polyposis syndromes. MSH6 mutations appear to be associated with atypical HNPCC and in particular with development of endometrial carcinoma or atypical endometrial hyperplasia, the presumed precursor of endometrial cancer. Defects in MSH6 are also found in familial colorectal cancers (suspected or incomplete HNPCC) that do not fulfill the Amsterdam criteria for HNPCC.<ref>PMID:9354786</ref> <ref>PMID:10521294</ref> <ref>PMID:10480359</ref> <ref>PMID:11586295</ref> <ref>PMID:12658575</ref> <ref>PMID:14974087</ref> <ref>PMID:15365995</ref> <ref>PMID:22102614</ref>   Defects in MSH6 are a cause of susceptibility to endometrial cancer (ENDMC) [MIM:[https://omim.org/entry/608089 608089].  Defects in MSH6 are a cause of mismatch repair cancer syndrome (MMRCS) [MIM:[https://omim.org/entry/276300 276300]; also known as Turcot syndrome or brain tumor-polyposis syndrome 1 (BTPS1). MMRCS is an autosomal dominant disorder characterized by malignant tumors of the brain associated with multiple colorectal adenomas. Skin features include sebaceous cysts, hyperpigmented and cafe au lait spots.<ref>PMID:17557300</ref> 
== Function ==
[https://www.uniprot.org/uniprot/MSH6_HUMAN MSH6_HUMAN] Component of the post-replicative DNA mismatch repair system (MMR). Heterodimerizes with MSH2 to form MutS alpha, which binds to DNA mismatches thereby initiating DNA repair. When bound, MutS alpha bends the DNA helix and shields approximately 20 base pairs, and recognizes single base mismatches and dinucleotide insertion-deletion loops (IDL) in the DNA. After mismatch binding, forms a ternary complex with the MutL alpha heterodimer, which is thought to be responsible for directing the downstream MMR events, including strand discrimination, excision, and resynthesis. ATP binding and hydrolysis play a pivotal role in mismatch repair functions. The ATPase activity associated with MutS alpha regulates binding similar to a molecular switch: mismatched DNA provokes ADP-->ATP exchange, resulting in a discernible conformational transition that converts MutS alpha into a sliding clamp capable of hydrolysis-independent diffusion along the DNA backbone. This transition is crucial for mismatch repair. MutS alpha may also play a role in DNA homologous recombination repair.<ref>PMID:9822680</ref> <ref>PMID:9822679</ref> <ref>PMID:9564049</ref> <ref>PMID:10078208</ref> <ref>PMID:10660545</ref> <ref>PMID:15064730</ref> 

==See Also==
*[[DNA mismatch repair protein 3D structures|DNA mismatch repair protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Arrowsmith CH]]
[[Category: Bountra C]]
[[Category: Edwards AM]]
[[Category: Min J]]
[[Category: Qin S]]
[[Category: Structural genomic]]
[[Category: Tempel W]]