View source for 3cnm


==Crystal Structure of Phenazine Biosynthesis Protein PhzA/B from Burkholderia cepacia R18194, DHHA complex==
<StructureSection load='3cnm' size='340' side='right'caption='[[3cnm]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3cnm]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Burkholderia_sp. Burkholderia sp.]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CNM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3CNM 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]] 1.65&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=HHA:(2S,3S)-TRANS-2,3-DIHYDRO-3-HYDROXYANTHRANILIC+ACID'>HHA</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=3cnm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3cnm OCA], [https://pdbe.org/3cnm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3cnm RCSB], [https://www.ebi.ac.uk/pdbsum/3cnm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3cnm ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q396C9_BURL3 Q396C9_BURL3] 
== 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/cn/3cnm_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/main_output.php?pdb_ID=3cnm ConSurf].
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== Publication Abstract from PubMed ==
Phenazines are redox-active bacterial secondary metabolites that participate in important biological processes such as the generation of toxic reactive oxygen species and the reduction of environmental iron. Their biosynthesis from chorismic acid depends on enzymes encoded by the phz operon, but many details of the pathway remain unclear. It previously was shown that phenazine biosynthesis involves the symmetrical head-to-tail double condensation of two identical amino-cyclohexenone molecules to a tricyclic phenazine precursor. While this key step can proceed spontaneously in vitro, we show here that it is catalyzed by PhzA/B, a small dimeric protein of the Delta(5)-3-ketosteroid isomerase/nuclear transport factor 2 family, and we reason that this catalysis is required in vivo. Crystal structures in complex with analogues of the substrate and product suggest that PhzA/B accelerates double imine formation by orienting two substrate molecules and by neutralizing the negative charge of tetrahedral intermediates through protonation. HPLC-coupled NMR reveals that the condensation product rearranges further, which is probably important to prevent back-hydrolysis, and may also be catalyzed within the active site of PhzA/B. The rearranged tricyclic product subsequently undergoes oxidative decarboxylation in a metal-independent reaction involving molecular oxygen. This conversion does not seem to require enzymatic catalysis, explaining why phenazine-1-carboxylic acid is a major product even in strains that use phenazine-1,6-dicarboxylic acid as a precursor of strain-specific phenazine derivatives.

PhzA/B catalyzes the formation of the tricycle in phenazine biosynthesis.,Ahuja EG, Janning P, Mentel M, Graebsch A, Breinbauer R, Hiller W, Costisella B, Thomashow LS, Mavrodi DV, Blankenfeldt W J Am Chem Soc. 2008 Dec 17;130(50):17053-61. PMID:19053436<ref>PMID:19053436</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 3cnm" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Burkholderia sp]]
[[Category: Large Structures]]
[[Category: Ahuja EG]]
[[Category: Blankenfeldt W]]