View source for 6ubn


==Crystal structure of D678E GoxA bound to glycine==
<StructureSection load='6ubn' size='340' side='right'caption='[[6ubn]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6ubn]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudoalteromonas_luteoviolacea_DSM_6061 Pseudoalteromonas luteoviolacea DSM 6061]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6UBN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6UBN 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]] 2.15&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=TNQ:6-[(carboxymethyl)amino]-7-hydroxy-L-tryptophan'>TNQ</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=6ubn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ubn OCA], [https://pdbe.org/6ubn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ubn RCSB], [https://www.ebi.ac.uk/pdbsum/6ubn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ubn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A161XU12_9GAMM A0A161XU12_9GAMM] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
PlGoxA from Pseudoalteromonas luteoviolacea is a glycine oxidase that utilizes a protein-derived cysteine tryptophylquinone (CTQ) cofactor. A notable feature of its catalytic mechanism is that it forms a stable product-reduced CTQ adduct that is not hydrolyzed in the absence of O2 Asp-678 resides near the quinone moiety of PlGoxA, and an Asp is structurally conserved in this position in all tryptophylquinone enzymes. In those other enzymes, mutation of that Asp results in no or negligible CTQ formation. In this study, mutation of Asp-678 in PlGoxA did not abolish CTQ formation. This allowed for the first time, studying the role of this residue in catalysis. D678A and D678N substitutions yielded enzyme variants with CTQ, which did not react with glycine, although glycine was present in the crystal structures in the active site. D678E PlGoxA was active, but exhibited a much slower k cat This mutation altered the kinetic mechanism of the reductive half-reaction such that one could observe a previously undetected reactive intermediate, an initial substrate-oxidized CTQ adduct, which converted to the product-reduced CTQ adduct. These results indicate that Asp-678 is involved in the initial deprotonation of the amino group of glycine, enabling nucleophilic attack of CTQ, as well as the deprotonation of the substrate-oxidized CTQ adduct, which is coupled to CTQ reduction. The structures also suggest that Asp-678 is acting as a proton relay that directs these protons to a water channel that connects the active sites on the subunits of this homotetrameric enzyme.

Kinetic and structural evidence that Asp-678 plays multiple roles in catalysis by the quinoprotein glycine oxidase.,Mamounis KJ, Avalos D, Yukl ET, Davidson VL J Biol Chem. 2019 Oct 15. pii: RA119.011255. doi: 10.1074/jbc.RA119.011255. PMID:31615898<ref>PMID:31615898</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6ubn" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudoalteromonas luteoviolacea DSM 6061]]
[[Category: Yukl ET]]