View source for 3hvs


==Escherichia coli Thiol peroxidase (Tpx) wild type disulfide form==
<StructureSection load='3hvs' size='340' side='right'caption='[[3hvs]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3hvs]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HVS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HVS 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]] 1.8&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</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=3hvs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hvs OCA], [https://pdbe.org/3hvs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3hvs RCSB], [https://www.ebi.ac.uk/pdbsum/3hvs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3hvs ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TPX_ECOLI TPX_ECOLI] Has antioxidant activity. Could remove peroxides or H(2)O(2) within the catalase- and peroxidase-deficient periplasmic space.[HAMAP-Rule:MF_00269]
== 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/hv/3hvs_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=3hvs ConSurf].
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== Publication Abstract from PubMed ==
Thiol peroxidases (Tpxs) are dimeric 2-Cys peroxiredoxins from bacteria that preferentially reduce alkyl hydroperoxides. Catalysis requires two conserved residues, the peroxidatic cysteine and the resolving cysteine, which are located in helix alpha(2) and helix alpha(3), respectively. The partial unraveling of helices alpha(2) and alpha(3) during catalysis allows for the formation of an intramolecular disulfide between these two residues. Here, we present three structures of Escherichia coli Tpx representing the fully folded (peroxide binding site intact), locally unfolded (disulfide bond), and partially locally unfolded (transitional state) conformations. We also compare known Tpx crystal structures and analyze the sequence-conservation patterns among nearly 300 Tpx sequences. Twelve fully conserved Tpx-specific residues cluster at the active site and dimer interface, and an additional 37 highly conserved residues are mostly located in a cradle providing the environment for helix alpha(2). Using the structures determined here as representative fully folded, transitional, and locally unfolded Tpx conformations, we describe in detail the structural changes associated with catalysis in the Tpx subfamily. Key insights include the description of a conserved hydrophobic collar around the active site, a set of conserved packing interactions between helices alpha(2) and alpha(3) that allow the local unfolding of alpha(2) to trigger the partial unfolding of alpha(3), a conserved dimer interface that anchors the ends of helices alpha(2) and alpha(3) to stabilize the active site during structural transitions, and a conserved set of residues constituting a cradle that stabilizes the two discrete conformations of helix alpha(2) involved in catalysis. The involvement of the dimer interface in stabilizing active-site folding and in forming the hydrophobic collar implies that Tpx is an obligate homodimer and explains the high conservation of interface residues.

Structural changes common to catalysis in the Tpx peroxiredoxin subfamily.,Hall A, Sankaran B, Poole LB, Karplus PA J Mol Biol. 2009 Nov 6;393(4):867-81. Epub 2009 Aug 21. PMID:19699750<ref>PMID:19699750</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 3hvs" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thiol peroxidase|Thiol peroxidase]]
*[[Thiol peroxidase 3D structures|Thiol peroxidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Hall A]]
[[Category: Karplus PA]]