View source for 4ifk


==Arginines 51 and 239* from a Neighboring Subunit are Essential for Catalysis in a Zinc-dependent Decarboxylase==
<StructureSection load='4ifk' size='340' side='right'caption='[[4ifk]], [[Resolution|resolution]] 2.01&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ifk]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_fluorescens Pseudomonas fluorescens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IFK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4IFK 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]] 2.012&#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=ZN:ZINC+ION'>ZN</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=4ifk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ifk OCA], [https://pdbe.org/4ifk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ifk RCSB], [https://www.ebi.ac.uk/pdbsum/4ifk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ifk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q83V25_PSEFL Q83V25_PSEFL] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Although the crystal structure of alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase from Pseudomonas fluorescens was solved as a dimer, this enzyme is a mixture of monomer, dimer, and higher order structures in solution. In this work, we found that the dimeric state, not the monomeric state, is the functionally active form. Two conserved arginine residues are present in the active site: Arg-51 and an intruding Arg-239* from the neighboring subunit. In this study, they were each mutated to alanine and lysine, and all four mutants were catalytically inactive. The mutants were also incapable of accommodating pyridine-2,6-dicarboxylic acid, a competitive inhibitor of the native enzyme, suggesting that the two Arg residues are involved in substrate binding. It was also observed that the decarboxylase activity was partially recovered in a heterodimer hybridization experiment when inactive R51(A/K) and R239(A/K) mutants were mixed together. Of the 20 crystal structures obtained from mixing inactive R51A and R239A homodimers that diffracted to a resolution lower than 3.00 A, two structures are clearly R51A/R239A heterodimers and belong to the C2 space group. They were refined to 1.80 and 2.00 A resolutions, respectively. Four of the remaining crystals are apparently single mutants and belong to the P42212 space group. In the heterodimer structures, one active site is shown to contain dual mutation of Ala-51 and Ala-239*, whereas the other contains the native Arg-51 and Arg-239* residues, identical to the wild-type structure. Thus, these observations provide the foundation for a molecular mechanism by which the oligomerization state of alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase could regulate the enzyme activity.

The power of two: arginine 51 and arginine 239* from a neighboring subunit are essential for catalysis in alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase.,Huo L, Davis I, Chen L, Liu A J Biol Chem. 2013 Oct 25;288(43):30862-71. doi: 10.1074/jbc.M113.496869. Epub, 2013 Sep 9. PMID:24019523<ref>PMID:24019523</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ifk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas fluorescens]]
[[Category: Chen L]]
[[Category: Davis I]]
[[Category: Huo L]]
[[Category: Liu A]]