View source for 3hqb


==Crystal structure of human desarg-C5A==
<StructureSection load='3hqb' size='340' side='right'caption='[[3hqb]], [[Resolution|resolution]] 3.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3hqb]] is a 2 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=3HQB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HQB 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]] 3.299&#8491;</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=3hqb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hqb OCA], [https://pdbe.org/3hqb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3hqb RCSB], [https://www.ebi.ac.uk/pdbsum/3hqb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3hqb 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).
== 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/hq/3hqb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=3hqb ConSurf].
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== Publication Abstract from PubMed ==
The anaphylatoxin C5a is derived from the complement component C5 during activation of the complement cascade. It is an important component in the pathogenesis of a number of inflammatory diseases. NMR structures of human and porcine C5a have been reported; these revealed a four-helix bundle stabilized by three disulfide bonds. The crystal structure of human desArg-C5a has now been determined in two crystal forms. Surprisingly, the protein crystallizes as a dimer and each monomer in the dimer has a three-helix core instead of the four-helix bundle noted in the NMR structure determinations. Furthermore, the N-terminal helices of the two monomers occupy different positions relative to the three-helix core and are completely different from the NMR structures. The physiological significance of these structural differences is unknown.

Structure of human desArg-C5a.,Cook WJ, Galakatos N, Boyar WC, Walter RL, Ealick SE Acta Crystallogr D Biol Crystallogr. 2010 Feb;66(Pt 2):190-7. Epub 2010 Jan 22. PMID:20124699<ref>PMID:20124699</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Complement C5 3D structures|Complement C5 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cook WJ]]
[[Category: Ealick SE]]