View source for 4eht


==Activator of the 2-Hydroxyisocaproyl-CoA dehydratase from Clostridium difficile with bound ADP==
<StructureSection load='4eht' size='340' side='right'caption='[[4eht]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4eht]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Clostridioides_difficile Clostridioides difficile]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4EHT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4EHT 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NH4:AMMONIUM+ION'>NH4</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=4eht FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4eht OCA], [https://pdbe.org/4eht PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4eht RCSB], [https://www.ebi.ac.uk/pdbsum/4eht PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4eht ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HADI_CLODI HADI_CLODI] Involved in the reductive branch of L-leucine fermentation. Required for the activation of (R)-2-hydroxyisocaproyl-CoA dehydratase. The reduced activator transfers one electron to the dehydratase concomitant with hydrolysis of ATP. This protein is extremely sensitive towards oxygen.<ref>PMID:15654892</ref> <ref>PMID:22827463</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Members of the 2-hydroxyacyl-CoA dehydratase enzyme family catalyze the beta,alpha-dehydration of various CoA-esters in the fermentation of amino acids by clostridia. Abstraction of the non-acidic beta-proton of the 2-hydroxyacyl-CoA compounds is achieved by the reductive generation of ketyl radicals on the substrate, which is initiated by the transfer of an electron at low redox potentials. The highly energetic electron needed on the dehydratase is donated by a [4Fe-4S] cluster containing ATPase, termed activator. We investigated the activator of the 2-hydroxyisocaproyl-CoA dehydratase from Clostridium difficile. The activator is a homodimeric protein structurally related to acetate and sugar kinases, Hsc70 and actin, which has a [4Fe-4S] cluster bound in the dimer interface. The crystal structures of the Mg-ADP, Mg-ADPNP and nucleotide-free states of the reduced activator have been solved at 1.6 - 3.0 A resolution, allowing us to define the position of Mg2+ and water molecules in the vicinity of the nucleotides and the [4Fe-4S] cluster. The structures reveal redox- and nucleotide dependent changes agreeing with the modulation of the reduction potential of the [4Fe-4S] cluster by conformational changes. We also investigated the propensity of the activator to form a complex with its cognate dehydratase in the presence of Mg-ADP and Mg-ADPNP and together with the structural data present a refined mechanistic scheme for the ATP-dependent electron transfer between activator and dehydratase.

On the ATP-dependent Activation of the Radical Enzyme (R)-2-Hydroxyisocaproyl-CoA Dehydratase.,Knauer SH, Buckel W, Dobbek H Biochemistry. 2012 Jul 24. PMID:22827463<ref>PMID:22827463</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4eht" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Clostridioides difficile]]
[[Category: Large Structures]]
[[Category: Dobbek H]]
[[Category: Knauer SH]]