View source for 5j32


==Isopropylmalate dehydrogenase in complex with isopropylmalate==
<StructureSection load='5j32' size='340' side='right'caption='[[5j32]], [[Resolution|resolution]] 1.93&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5j32]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5J32 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5J32 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]] 1.933&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IPM:3-ISOPROPYLMALIC+ACID'>IPM</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=5j32 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5j32 OCA], [https://pdbe.org/5j32 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5j32 RCSB], [https://www.ebi.ac.uk/pdbsum/5j32 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5j32 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LEU32_ARATH LEU32_ARATH] Catalyzes the oxidation of 3-carboxy-2-hydroxy-4-methylpentanoate (3-isopropylmalate) to 3-carboxy-4-methyl-2-oxopentanoate. The product decarboxylates to 4-methyl-2 oxopentanoate.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Isopropylmalate dehydrogenase (IPMDH) and 3-(2'-methylthio)ethylmalate dehydrogenase catalyze the oxidative decarboxylation of different beta-hydroxyacids in the leucine and methionine-derived glucosinolate biosynthesis pathways, respectively, in plants. Evolution of the glucosinolate biosynthetic enzyme from IPMDH results from a single amino acid substitution that alters substrate specificity. Here we present the x-ray crystal structures of Arabidopsis thaliana IPMDH2 (AtIPMDH2) in complex with either isopropylmalate and Mg2+ or NAD+. These structures reveal conformational changes that occur upon ligand binding and provide insight on the active site of the enzyme. The x-ray structures and kinetic analysis of site-directed mutants are consistent with a chemical mechanism in which Lys232 activates a water molecule for catalysis. Structural analysis of the AtIPMDH2 K232M mutant and isothermal titration calorimetry supports a key role of Lys232 in the reaction mechanism. This study suggests that IPMDH-like enzymes in both leucine and glucosinolate biosynthesis pathways use a common mechanism and that members of the beta-hydroxyacid reductive decarboxylase family employ different active site features for similar reactions.

Structure and Mechanism of Isopropylmalate Dehydrogenase from Arabidopsis thaliana: Insights on Leucine and Aliphatic Glucosinolate Biosynthesis.,Lee SG, Nwumeh R, Jez JM J Biol Chem. 2016 May 2. pii: jbc.M116.730358. PMID:27137927<ref>PMID:27137927</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5j32" style="background-color:#fffaf0;"></div>

==See Also==
*[[Isopropylmalate dehydrogenase|Isopropylmalate dehydrogenase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Arabidopsis thaliana]]
[[Category: Large Structures]]
[[Category: Jez JM]]
[[Category: Lee SG]]