View source for 3hpx


==Crystal structure of Mycobacterium tuberculosis LeuA active site domain 1-425 (truncation mutant delta:426-644)==
<StructureSection load='3hpx' size='340' side='right'caption='[[3hpx]], [[Resolution|resolution]] 2.03&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3hpx]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis_H37Rv Mycobacterium tuberculosis H37Rv]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HPX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HPX 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]] 2.03&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NI:NICKEL+(II)+ION'>NI</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=3hpx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3hpx OCA], [https://pdbe.org/3hpx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3hpx RCSB], [https://www.ebi.ac.uk/pdbsum/3hpx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3hpx ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/LEU1_MYCTU LEU1_MYCTU] Catalyzes the condensation of the acetyl group of acetyl-CoA with 3-methyl-2-oxobutanoate (2-oxoisovalerate) to form 3-carboxy-3-hydroxy-4-methylpentanoate (2-isopropylmalate) (By similarity).
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/hp/3hpx_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3hpx ConSurf].
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== Publication Abstract from PubMed ==
alpha-Isopropylmalate synthase (alpha-IPMS) catalyzes the metal-dependent aldol reaction between alpha-ketoisovalerate (alpha-KIV) and acetyl-coenzyme A (AcCoA) to give alpha-isopropylmalate (alpha-IPM). This reaction is the first committed step in the biosynthesis of leucine in bacteria. alpha-IPMS is homodimeric, with monomers consisting of (beta/alpha)(8) barrel catalytic domains fused to a C-terminal regulatory domain, responsible for binding leucine and providing feedback regulation for leucine biosynthesis. In these studies, we demonstrate that removal of the regulatory domain from the alpha-IPMS enzymes of both Neisseria meningitidis (NmeIPMS) and Mycobacterium tuberculosis (MtuIPMS) results in enzymes that are unable to catalyze the formation of alpha-IPM, although truncated NmeIPMS was still able to slowly hydrolyze AcCoA. The lack of catalytic activity of these truncation variants was confirmed by complementation studies with Escherichia coli cells lacking the alpha-IPMS gene, where transformation with the plasmids encoding the truncated alpha-IPMS enzymes was not able to rescue alpha-IPMS activity. X-ray crystal structures of both truncation variants reveal that both proteins are dimeric and that the catalytic sites of the proteins are intact, although the divalent metal ion that is thought to be responsible for activating substrate alpha-KIV is displaced slightly relative to its position in the substrate-bound, wild-type structure. Isothermal titration calorimetry and WaterLOGSY nuclear magnetic resonance experiments demonstrate that although these truncation variants are not able to catalyze the reaction between alpha-KIV and AcCoA, they are still able to bind the substrate alpha-KIV. It is proposed that the regulatory domain is crucial for ensuring protein dynamics necessary for competent catalysis.

Removal of the C-Terminal Regulatory Domain of alpha-Isopropylmalate Synthase Disrupts Functional Substrate Binding.,Huisman FH, Koon N, Bulloch EM, Baker HM, Baker EN, Squire CJ, Parker EJ Biochemistry. 2012 Mar 6. PMID:22352945<ref>PMID:22352945</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 3hpx" style="background-color:#fffaf0;"></div>

==See Also==
*[[2-isopropylmalate synthase 3D structures|2-isopropylmalate synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis H37Rv]]
[[Category: Baker EN]]
[[Category: Koon N]]
[[Category: Squire CJ]]