View source for 1apx


==CRYSTAL STRUCTURE OF RECOMBINANT ASCORBATE PEROXIDASE==
<StructureSection load='1apx' size='340' side='right'caption='[[1apx]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1apx]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pisum_sativum Pisum sativum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1APX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1APX 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</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=1apx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1apx OCA], [https://pdbe.org/1apx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1apx RCSB], [https://www.ebi.ac.uk/pdbsum/1apx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1apx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/APX1_PEA APX1_PEA] Plays a key role in hydrogen peroxide removal.
== 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/ap/1apx_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=1apx ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The crystal structure of recombinant pea cytosolic ascorbate peroxidase has been refined to an R = 0.19 for data between 8.0 and 2.2 A resolution and magnitude of F &gt; or = 2 sigma(magnitude of F). The refined model consists of four ascorbate peroxidase monomers consisting of 249 residues per monomer assembled into two homodimers, with one heme group per monomer. The ascorbate peroxidase model confirms that the pea cytosolic enzyme is a noncovalent homodimer held together by a series of ionic interactions arranged around the 2-fold noncrystallographic dimer axis. As expected from the high level of sequence identity (33%), the overall fold of the ascorbate peroxidase monomer closely resembles that of cytochrome c peroxidase. The average root mean square differences for 137 helical alpha-carbon atoms between the four ascorbate peroxidase monomers and cytochrome c peroxidase and for 249 topologically equivalent alpha-carbon atoms are 0.9 and 1.3 A, respectively. The active site structures are also the same, including the hydrogen-bonding interactions between the proximal His ligand, a buried Asp residue, and a Trp residue, whose indole ring is parallel to and in contact with the proximal His ligand just under the heme ring. This proximal Trp residue is thought to be the site of free radical formation in cytochrome c peroxidase compound I and is also essential for enzyme activity. The corresponding Trp in ascorbate peroxidase, Trp179, occupies exactly the same position. The most interesting, and possibly functionally important, difference between the two peroxidases is the presence of a cation binding site in ascorbate peroxidase located approximately 8 A from the alpha-carbon atom of Trp179.

Crystal structure of recombinant pea cytosolic ascorbate peroxidase.,Patterson WR, Poulos TL Biochemistry. 1995 Apr 4;34(13):4331-41. PMID:7703247<ref>PMID:7703247</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1apx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ascorbate peroxidase 3D structures|Ascorbate peroxidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pisum sativum]]
[[Category: Patterson WR]]
[[Category: Poulos TL]]