View source for 1ckl


==N-TERMINAL TWO DOMAINS OF HUMAN CD46 (MEMBRANE COFACTOR PROTEIN, MCP)==
<StructureSection load='1ckl' size='340' side='right'caption='[[1ckl]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ckl]] is a 6 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=1CKL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CKL 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]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=1ckl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ckl OCA], [https://pdbe.org/1ckl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ckl RCSB], [https://www.ebi.ac.uk/pdbsum/1ckl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ckl ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/MCP_HUMAN MCP_HUMAN] Defects in CD46 are a cause of susceptibility to hemolytic uremic syndrome atypical type 2 (AHUS2) [MIM:[https://omim.org/entry/612922 612922]. An atypical form of hemolytic uremic syndrome. It is a complex genetic disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, renal failure and absence of episodes of enterocolitis and diarrhea. In contrast to typical hemolytic uremic syndrome, atypical forms have a poorer prognosis, with higher death rates and frequent progression to end-stage renal disease. Note=Susceptibility to the development of atypical hemolytic uremic syndrome can be conferred by mutations in various components of or regulatory factors in the complement cascade system. Other genes may play a role in modifying the phenotype. Patients with CD46 mutations seem to have an overall better prognosis compared to patients carrying CFH mutations.<ref>PMID:14615110</ref> <ref>PMID:14566051</ref> <ref>PMID:16621965</ref> <ref>PMID:16386793</ref> <ref>PMID:20513133</ref> 
== Function ==
[https://www.uniprot.org/uniprot/MCP_HUMAN MCP_HUMAN] Acts as a cofactor for complement factor I, a serine protease which protects autologous cells against complement-mediated injury by cleaving C3b and C4b deposited on host tissue. May be involved in the fusion of the spermatozoa with the oocyte during fertilization. Also acts as a costimulatory factor for T-cells which induces the differentiation of CD4+ into T-regulatory 1 cells. T-regulatory 1 cells suppress immune responses by secreting interleukin-10, and therefore are thought to prevent autoimmunity. A number of viral and bacterial pathogens seem to exploit this property and directly induce an immunosuppressive phenotype in T-cells by binding to CD46.<ref>PMID:10843656</ref> <ref>PMID:12540904</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ck/1ckl_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1ckl ConSurf].
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== Publication Abstract from PubMed ==
Measles virus is a paramyxovirus which, like other members of the family such as respiratory syncytial virus, is a major cause of morbidity and mortality worldwide. The cell surface receptor for measles virus in humans is CD46, a complement cofactor. We report here the crystal structure at 3.1 A resolution of the measles virus-binding fragment of CD46. The structure reveals the architecture and spatial arrangement of two glycosylated short consensus repeats with a pronounced interdomain bend and some flexibility at the domain interface. Amino acids involved in measles virus binding define a large, glycan-free surface that extends from the top of the first to the bottom of the second repeat. The extended virus-binding surface of CD46 differs strikingly from those reported for the human virus receptor proteins CD4 and intercellular cell adhesion molecule-1 (ICAM-1), suggesting that the CD46 structure utilizes a novel mode of virus recognition. A highly hydrophobic and protruding loop at the base of the first repeat bears a critical virus-binding residue, thereby defining an important recognition epitope. Molecules that mimic the conformation of this loop potentially could be effective anti-viral agents by preventing binding of measles virus to CD46.

Crystal structure of two CD46 domains reveals an extended measles virus-binding surface.,Casasnovas JM, Larvie M, Stehle T EMBO J. 1999 Jun 1;18(11):2911-22. PMID:10357804<ref>PMID:10357804</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1ckl" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Casasnovas J]]
[[Category: Larvie M]]
[[Category: Stehle T]]