View source for 4zxa


==Crystal Structure of hydroquinone 1,2-dioxygenase PnpCD in complex with Cd2+ and 4-hydroxybenzonitrile==
<StructureSection load='4zxa' size='340' side='right'caption='[[4zxa]], [[Resolution|resolution]] 2.49&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4zxa]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_sp._WBC-3 Pseudomonas sp. WBC-3]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZXA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZXA FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CD:CADMIUM+ION'>CD</scene>, <scene name='pdbligand=H8N:4-HYDROXYBENZONITRILE'>H8N</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=4zxa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zxa OCA], [https://pdbe.org/4zxa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zxa RCSB], [https://www.ebi.ac.uk/pdbsum/4zxa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zxa ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C1I210_PSEWB C1I210_PSEWB] 
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== Publication Abstract from PubMed ==
Aerobic microorganisms have evolved a variety of pathways to degrade aromatic and heterocyclic compounds. However, only several classes of oxygenolytic fission reaction have been identified for the critical ring cleavage dioxygenases. Among them, the most well studied dioxygenases proceed via catecholic intermediates, followed by noncatecholic hydroxy-substituted aromatic carboxylic acids. Therefore, the recently reported hydroquinone 1,2-dioxygenases add to the diversity of ring cleavage reactions. Two-subunit hydroquinone 1,2-dioxygenase PnpCD, the key enzyme in the hydroquinone pathway of para-nitrophenol degradation, catalyzes the ring cleavage of hydroquinone to gamma-hydroxymuconic semialdehyde. Here, we report three PnpCD structures, named apo-PnpCD, PnpCD-Fe(3+), and PnpCD-Cd(2+)-HBN (substrate analog hydroxyenzonitrile), respectively. Structural analysis showed that both the PnpC and the C-terminal domains of PnpD comprise a conserved cupin fold, whereas PnpC cannot form a competent metal binding pocket as can PnpD cupin. Four residues of PnpD (His-256, Asn-258, Glu-262, and His-303) were observed to coordinate the iron ion. The Asn-258 coordination is particularly interesting because this coordinating residue has never been observed in the homologous cupin structures of PnpCD. Asn-258 is proposed to play a pivotal role in binding the iron prior to the enzymatic reaction, but it might lose coordination to the iron when the reaction begins. PnpD also consists of an intriguing N-terminal domain that might have functions other than nucleic acid binding in its structural homologs. In summary, PnpCD has no apparent evolutionary relationship with other iron-dependent dioxygenases and therefore defines a new structural class. The study of PnpCD might add to the understanding of the ring cleavage of dioxygenases.

Crystal Structure of PnpCD, a Two-subunit Hydroquinone 1,2-Dioxygenase, Reveals a Novel Structural Class of Fe2+-dependent Dioxygenases.,Liu S, Su T, Zhang C, Zhang WM, Zhu D, Su J, Wei T, Wang K, Huang Y, Guo L, Xu S, Zhou NY, Gu L J Biol Chem. 2015 Oct 2;290(40):24547-60. doi: 10.1074/jbc.M115.673558. Epub 2015, Aug 24. PMID:26304122<ref>PMID:26304122</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 4zxa" style="background-color:#fffaf0;"></div>

==See Also==
*[[Dioxygenase 3D structures|Dioxygenase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas sp. WBC-3]]
[[Category: Gu L]]
[[Category: Liu S]]
[[Category: Su T]]
[[Category: Zhang C]]