View source for 3hq8

==CcpA from G. sulfurreducens S134P/V135K variant==
<StructureSection load='3hq8' size='340' side='right' caption='[[3hq8]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3hq8]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Geobacter_sulfurreducens Geobacter sulfurreducens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HQ8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3HQ8 FirstGlance]. <br>
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene><br>
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3hq6|3hq6]], [[3hq7|3hq7]], [[3hq9|3hq9]]</td></tr>
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ccpA, ccpA-2, GSU2813 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=35554 Geobacter sulfurreducens])</td></tr>
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Cytochrome-c_peroxidase Cytochrome-c peroxidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.5 1.11.1.5] </span></td></tr>
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3hq8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hq8 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3hq8 RCSB], [http://www.ebi.ac.uk/pdbsum/3hq8 PDBsum]</span></td></tr>
<table>
== 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/3hq8_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/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacterial di-heme cytochrome c peroxidases (CcpAs) protect the cell from reactive oxygen species by reducing hydrogen peroxide to water. The enzymes are c-type cytochromes, with both heme groups covalently attached to the protein chain via a characteristic binding motif. The genome of the dissimilatory metal-reducing bacterium Geobacter sulfurreducens revealed the presence of a ccpA gene and we isolated the gene product after recombinant expression in Escherichia coli. CcpA from G. sulfurreducens exhibited in vitro peroxidase activity with ABTS(2-) [2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid)] as an electron donor, and the three-dimensional structure of the dimeric enzyme has been determined to high resolution. For activation, CcpA commonly requires reduction, with the exception of the Nitrosomonas europaea enzyme that retains its activity in the oxidized state. A G94K/K97Q/R100I triple point mutant was created to mimic the critical loop region of N. europaea CcpA, but its crystal structure revealed that the inactive, bis-histidinyl-coordinated form of the active-site heme group was retained. Subsequent mutational studies thus addressed an adjacent loop region, where a change in secondary structure accompanies the reductive activation of the enzyme. While an A124K/K128A double mutant did not show significant changes, the CcpA variants S134P/V135K and S134P led to a distortion of the loop region, accompanied by an opening of the active-site loop, leaving the enzyme in a constitutively active state.

CcpA from Geobacter sulfurreducens is a basic di-heme cytochrome c peroxidase.,Hoffmann M, Seidel J, Einsle O J Mol Biol. 2009 Nov 6;393(4):951-65. Epub 2009 Sep 6. PMID:19735665<ref>PMID:19735665</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Cytochrome c peroxidase|Cytochrome c peroxidase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cytochrome-c peroxidase]]
[[Category: Geobacter sulfurreducens]]
[[Category: Einsle, O.]]
[[Category: Hoffmann, M.]]
[[Category: Seidel, J.]]
[[Category: Cytochrome c peroxidase]]
[[Category: Oxidoreductase]]
[[Category: Peroxidase]]