View source for 5flh


==Free state of Ni-quercetinase==
<StructureSection load='5flh' size='340' side='right'caption='[[5flh]], [[Resolution|resolution]] 1.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5flh]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_sp._FLA Streptomyces sp. FLA]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5FLH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5FLH 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]] 1.802&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DMS:DIMETHYL+SULFOXIDE'>DMS</scene>, <scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</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=5flh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5flh OCA], [https://pdbe.org/5flh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5flh RCSB], [https://www.ebi.ac.uk/pdbsum/5flh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5flh ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A2VA43_9ACTN A2VA43_9ACTN] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Quercetin 2,4-dioxygenase (quercetinase) from Streptomyces uses nickel as the active-site cofactor to catalyze oxidative cleavage of the flavonol quercetin. How this unusual active-site metal supports catalysis and O2 activation is under debate. We present crystal structures of Ni-quercetinase in three different states, thus providing direct insight into how quercetin and O2 are activated at the Ni(2+) ion. The Ni(2+) ion is coordinated by three histidine residues and a glutamate residue (E(76) ) in all three states. Upon binding, quercetin replaces one water ligand at Ni and is stabilized by a short hydrogen bond through E(76) , the carboxylate group of which rotates by 90 degrees . This conformational change weakens the interaction between Ni and the remaining water ligand, thereby preparing a coordination site at Ni to bind O2 . O2 binds side-on to the Ni(2+) ion and is perpendicular to the C2-C3 and C3-C4 bonds of quercetin, which are cleaved in the following reaction steps.

Quercetin 2,4-Dioxygenase Activates Dioxygen in a Side-On O2 -Ni Complex.,Jeoung JH, Nianios D, Fetzner S, Dobbek H Angew Chem Int Ed Engl. 2016 Mar 1;55(10):3281-4. doi: 10.1002/anie.201510741., Epub 2016 Feb 5. PMID:26846734<ref>PMID:26846734</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5flh" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces sp. FLA]]
[[Category: Dobbek H]]
[[Category: Fetzner S]]
[[Category: Jeoung J-H]]
[[Category: Nianios D]]