View source for 2rlq


==NMR structure of CCP modules 2-3 of complement factor H==
<StructureSection load='2rlq' size='340' side='right'caption='[[2rlq]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2rlq]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2RLQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2RLQ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 29 models</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=2rlq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2rlq OCA], [https://pdbe.org/2rlq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2rlq RCSB], [https://www.ebi.ac.uk/pdbsum/2rlq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2rlq ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/CFAH_HUMAN CFAH_HUMAN] Genetic variations in CFH are associated with basal laminar drusen (BLD) [MIM:[https://omim.org/entry/126700 126700]; also known as drusen of Bruch membrane or cuticular drusen or grouped early adult-onset drusen. Drusen are extracellular deposits that accumulate below the retinal pigment epithelium on Bruch membrane. Basal laminar drusen refers to an early adult-onset drusen phenotype that shows a pattern of uniform small, slightly raised yellow subretinal nodules randomly scattered in the macula. In later stages, these drusen often become more numerous, with clustered groups of drusen scattered throughout the retina. In time these small basal laminar drusen may expand and ultimately lead to a serous pigment epithelial detachment of the macula that may result in vision loss.  Defects in CFH are the cause of complement factor H deficiency (CFHD) [MIM:[https://omim.org/entry/609814 609814]. A disorder that can manifest as several different phenotypes, including asymptomatic, recurrent bacterial infections, and renal failure. Laboratory features usually include decreased serum levels of factor H, complement component C3, and a decrease in other terminal complement components, indicating activation of the alternative complement pathway. It is associated with a number of renal diseases with variable clinical presentation and progression, including membranoproliferative glomerulonephritis and atypical hemolytic uremic syndrome.<ref>PMID:9312129</ref> <ref>PMID:10803850</ref> <ref>PMID:11170895</ref> <ref>PMID:11170896</ref> <ref>PMID:11158219</ref> <ref>PMID:12020532</ref> <ref>PMID:14978182</ref> <ref>PMID:16612335</ref>   Defects in CFH are a cause of susceptibility to hemolytic uremic syndrome atypical type 1 (AHUS1) [MIM:[https://omim.org/entry/235400 235400]. 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.<ref>PMID:14978182</ref> <ref>PMID:9551389</ref> <ref>PMID:10577907</ref> <ref>PMID:10762557</ref> <ref>PMID:11851332</ref> <ref>PMID:14583443</ref> <ref>PMID:12960213</ref> <ref>PMID:20513133</ref>   Genetic variation in CFH is associated with age-related macular degeneration type 4 (ARMD4) [MIM:[https://omim.org/entry/610698 610698]. ARMD is a multifactorial eye disease and the most common cause of irreversible vision loss in the developed world. In most patients, the disease is manifest as ophthalmoscopically visible yellowish accumulations of protein and lipid (known as drusen) that lie beneath the retinal pigment epithelium and within an elastin-containing structure known as Bruch membrane.<ref>PMID:22019782</ref> 
== Function ==
[https://www.uniprot.org/uniprot/CFAH_HUMAN CFAH_HUMAN] Factor H functions as a cofactor in the inactivation of C3b by factor I and also increases the rate of dissociation of the C3bBb complex (C3 convertase) and the (C3b)NBB complex (C5 convertase) in the alternative complement pathway.
== 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/rl/2rlq_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=2rlq ConSurf].
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== Publication Abstract from PubMed ==
Factor H is a regulatory glycoprotein of the complement system. We expressed the three N-terminal complement control protein modules of human factor H (FH1-3) and confirmed FH1-3 to be the minimal unit with cofactor activity for C3b proteolysis by factor I. We reconstructed FH1-3 from NMR-derived structures of FH1-2 and FH2-3 revealing an approximately 105-A-long rod-like arrangement of the modules. In structural comparisons with other C3b-engaging proteins, factor H module 3 most closely resembles factor B module 3, consistent with factor H competing with factor B for binding C3b. Factor H modules 1, 2, and 3 each has a similar backbone structure to first, second, and third modules, respectively, of functional sites in decay accelerating factor and complement receptor type 1; the equivalent intermodular tilt and twist angles are also broadly similar. Resemblance between molecular surfaces is closest for first modules but absent in the case of second modules. Substitution of buried Val-62 with Ile (a factor H single nucleotide polymorphism potentially protective for age-related macular degeneration and dense deposit disease) causes rearrangements within the module 1 core and increases thermal stability but does not disturb the interface with module 2. Replacement of partially exposed (in module 1) Arg-53 by His (an atypical hemolytic uremic syndrome-linked mutation) did not impair structural integrity at 37 degrees C, but this FH1-2 mutant was less stable at higher temperatures; furthermore, chemical shift differences indicated potential for small structural changes at the module 1-2 interface.

Structure of the N-terminal region of complement factor H and conformational implications of disease-linked sequence variations.,Hocking HG, Herbert AP, Kavanagh D, Soares DC, Ferreira VP, Pangburn MK, Uhrin D, Barlow PN J Biol Chem. 2008 Apr 4;283(14):9475-87. Epub 2008 Feb 5. PMID:18252712<ref>PMID:18252712</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 2rlq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Complement factor 3D structures|Complement factor 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Barlow PN]]
[[Category: Herbert AP]]
[[Category: Hocking HG]]
[[Category: Kavanagh D]]
[[Category: Pangburn MK]]
[[Category: Uhrin D]]