6h04: Difference between revisions
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The | ==Closed conformation of the Membrane Attack Complex== | ||
<SX load='6h04' size='340' side='right' viewer='molstar' caption='[[6h04]], [[Resolution|resolution]] 5.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6h04]] is a 24 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=6H04 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6H04 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]] 5.6Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=6h04 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6h04 OCA], [https://pdbe.org/6h04 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6h04 RCSB], [https://www.ebi.ac.uk/pdbsum/6h04 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6h04 ProSAT]</span></td></tr> | |||
</table> | |||
== Disease == | |||
[https://www.uniprot.org/uniprot/CO5_HUMAN CO5_HUMAN] Defects in C5 are the cause of complement component 5 deficiency (C5D) [MIM:[https://omim.org/entry/609536 609536]. A rare defect of the complement classical pathway associated with susceptibility to severe recurrent infections, predominantly by Neisseria gonorrhoeae or Neisseria meningitidis. Note=An association study of C5 haplotypes and genotypes in individuals with chronic hepatitis C virus infection shows that individuals homozygous for the C5_1 haplotype have a significantly higher stage of liver fibrosis than individuals carrying at least 1 other allele (PubMed:15995705). | |||
== Function == | |||
[https://www.uniprot.org/uniprot/CO5_HUMAN CO5_HUMAN] Activation of C5 by a C5 convertase initiates the spontaneous assembly of the late complement components, C5-C9, into the membrane attack complex. C5b has a transient binding site for C6. The C5b-C6 complex is the foundation upon which the lytic complex is assembled. Derived from proteolytic degradation of complement C5, C5 anaphylatoxin is a mediator of local inflammatory process. It induces the contraction of smooth muscle, increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes. C5a also stimulates the locomotion of polymorphonuclear leukocytes (chemokinesis) and direct their migration toward sites of inflammation (chemotaxis). | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The membrane attack complex (MAC) is one of the immune system's first responders. Complement proteins assemble on target membranes to form pores that lyse pathogens and impact tissue homeostasis of self-cells. How MAC disrupts the membrane barrier remains unclear. Here we use electron cryo-microscopy and flicker spectroscopy to show that MAC interacts with lipid bilayers in two distinct ways. Whereas C6 and C7 associate with the outer leaflet and reduce the energy for membrane bending, C8 and C9 traverse the bilayer increasing membrane rigidity. CryoEM reconstructions reveal plasticity of the MAC pore and demonstrate how C5b6 acts as a platform, directing assembly of a giant beta-barrel whose structure is supported by a glycan scaffold. Our work provides a structural basis for understanding how beta-pore forming proteins breach the membrane and reveals a mechanism for how MAC kills pathogens and regulates cell functions. | |||
CryoEM reveals how the complement membrane attack complex ruptures lipid bilayers.,Menny A, Serna M, Boyd CM, Gardner S, Joseph AP, Morgan BP, Topf M, Brooks NJ, Bubeck D Nat Commun. 2018 Dec 14;9(1):5316. doi: 10.1038/s41467-018-07653-5. PMID:30552328<ref>PMID:30552328</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 6h04" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Complement C5 3D structures|Complement C5 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</SX> | |||
[[Category: Homo sapiens]] | |||
[[Category: Large Structures]] | |||
[[Category: Boyd CM]] | |||
[[Category: Bubeck D]] | |||
[[Category: Gardner S]] | |||
[[Category: Joseph AP]] | |||
[[Category: Menny A]] | |||
[[Category: Serna M]] | |||
[[Category: Topf M]] | |||