View source for 6mgt


==Crystal structure of alpha-Amino-beta-Carboxymuconate-epsilon-Semialdehyde Decarboxylase Mutant H110A==
<StructureSection load='6mgt' size='340' side='right'caption='[[6mgt]], [[Resolution|resolution]] 2.77&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6mgt]] 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=6MGT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6MGT 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]] 2.77&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</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=6mgt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6mgt OCA], [https://pdbe.org/6mgt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6mgt RCSB], [https://www.ebi.ac.uk/pdbsum/6mgt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6mgt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q83V25_PSEFL Q83V25_PSEFL] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
alpha-Amino-beta-carboxymuconate-&epsilon;-semialdehyde decarboxylase (ACMSD) plays an important role in L-tryptophan degradation via the kynurenine pathway. ACMSD forms a homodimer and is functionally inactive as a monomer because its catalytic assembly requires an arginine residue from a neighboring subunit. However, how the oligomeric state and self-association of ACMSD are controlled in solution remains unexplored. Here, we demonstrate that ACMSD from Pseudomonas fluorescens can self-assemble into homodimer, tetramer, and higher-order structures. Using size-exclusion chromatography coupled with small-angle X-ray scattering (SEC-SAXS) analysis, we investigated the ACMSD tetramer structure, and fitting the SAXS data with X-ray crystal structures of the monomeric component; we could generate a pseudo-atomic structure of the tetramer. This analysis revealed a tetramer model of ACMSD as a head-on dimer of dimers. We observed that the tetramer is catalytically more active than the dimer and is in equilibrium with the monomer and dimer. Substituting a critical residue of the dimer-dimer interface, His-110, altered the tetramer dissociation profile by increasing the higher-order oligomer portion in solution without changing the X-ray crystal structure. ACMSD self-association was affected by pH, ionic strength, and other electrostatic interactions. Alignment of ACMSD sequences revealed that His-110 is highly conserved in a few bacteria that utilize nitrobenzoic acid as a sole source of carbon and energy, suggesting a dedicated functional role of ACMSD's self-assembly into the tetrameric and higher-order structures. These results indicate that the dynamic oligomerization status potentially regulates ACMSD activity and that SEC-SAXS coupled with X-ray crystallography is a powerful tool for studying protein self-association.

Quaternary structure of alpha-amino-beta-carboxymuconate-&epsilon;-semialdehyde decarboxylase (ACMSD) controls its activity.,Yang Y, Davis I, Matsui T, Rubalcava I, Liu A J Biol Chem. 2019 Jun 12. pii: RA119.009035. doi: 10.1074/jbc.RA119.009035. PMID:31189654<ref>PMID:31189654</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6mgt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas fluorescens]]
[[Category: Daivs I]]
[[Category: Liu A]]
[[Category: Matsui T]]
[[Category: Rubalcava I]]
[[Category: Yang Y]]