View source for 9y72


==Structure of Mycobacterium tuberculosis pyruvate dehydrogenase complex E2p core subunit DlaT in a two-hexamer state==
<StructureSection load='9y72' size='340' side='right'caption='[[9y72]], [[Resolution|resolution]] 2.51&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9y72]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9Y72 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9Y72 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.51&#8491;</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=9y72 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9y72 OCA], [https://pdbe.org/9y72 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9y72 RCSB], [https://www.ebi.ac.uk/pdbsum/9y72 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9y72 ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The pyruvate dehydrogenase complex (PDHc) is a universally conserved multienzyme system that converts pyruvate into acetyl-CoA for entry into the TCA cycle and for NADH production. Its central scaffold, the dihydrolipoyl transacetylase (E2p), forms an oligomeric inner core that recruits pyruvate dehydrogenase (E1p) and dihydrolipoyl dehydrogenase (E3). All previously characterized PDHc assemblies adopt either an octahedral 24-mer or an icosahedral 60-mer E2p core, each constructed from trimeric building blocks. We recently showed that the Mycobacterium tuberculosis (Mtb) E2p protein DlaT also functions as the core of the pathogen's peroxynitrite reductase/peroxidase (PNR/P) complex. Here, using cryo-EM, we demonstrate that DlaT assembles into discrete hexamers and dodecamers at micromolar concentrations, which approximate intracellular DlaT concentrations in Mtb. Structure-guided mutagenesis combined with in vitro activity assays indicate that the hexamer represents the functional E2p core of the Mtb PDHc. This noncanonical architecture arises from unique interfaces between DlaT trimers that preclude formation of the classic spherical 24- or 60-mer structures. We propose that this specialized E2p organization enables Mtb to regulate metabolic activities and to remodel the E2p core for engagement in the PNR/P antioxidant pathway under stress. Our findings reveal an unexpected diversity in PDHc architecture and uncover a distinct organization principle for the core metabolic complex in mycobacteria.

Mycobacterium tuberculosis assembles a unique hexameric E2p core of the pyruvate dehydrogenase complex.,Hsu HC, Bonnet I, Bryk R, Li H J Biol Chem. 2026 Feb 12:111284. doi: 10.1016/j.jbc.2026.111284. PMID:41690596<ref>PMID:41690596</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 9y72" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Hsu HC]]
[[Category: Li H]]