View source for 9uoe


==Glycogen phosphorylase tetramer from E. coli==
<StructureSection load='9uoe' size='340' side='right'caption='[[9uoe]], [[Resolution|resolution]] 2.63&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9uoe]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BL21(DE3) Escherichia coli BL21(DE3)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9UOE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9UOE 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]] 2.63&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LLP:(2S)-2-AMINO-6-[[3-HYDROXY-2-METHYL-5-(PHOSPHONOOXYMETHYL)PYRIDIN-4-YL]METHYLIDENEAMINO]HEXANOIC+ACID'>LLP</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=9uoe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9uoe OCA], [https://pdbe.org/9uoe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9uoe RCSB], [https://www.ebi.ac.uk/pdbsum/9uoe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9uoe ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Glycogen phosphorylase (GP) plays a central role in glycogen metabolism. While the structure and regulation of mammalian GPs have been extensively studied, the corresponding mechanisms in gut bacterial GPs remain poorly understood. Here, we investigate GPs from Escherichia coli (EcGP), Segatella copri (ScGP), and Dorea longicatena (DlGP), which represent three phylogenetic clades of GPs, using enzymatic assays, cryo-electron microscopy (cryo-EM), and X-ray crystallography. We find that ScGP forms a unique pentamer that undergoes adenosine monophosphate (AMP)-dependent assembly into a dimer-of-pentamer, which inhibits activity by restricting substrate access to the catalytic site. EcGP exists in equilibrium among monomers, dimers, and tetramers, with AMP promoting tetramer dissociation and enhancing catalytic efficiency. In contrast, DlGP remains predominantly monomeric and is unresponsive to AMP. These findings uncover structural and regulatory diversity among gut bacterial GPs. Notably, the oligomeric states of GPs modulate substrate accessibility and enzyme activation, suggesting a distinct mode of allosteric regulation beyond the canonical T-to-R transition model. Because bacterial GPs contribute to the generation of glucose, their regulation may influence the composition of gut-derived metabolites that affect host glucose homeostasis and insulin sensitivity. Our study provides mechanistic insight into the structural and functional diversity of gut bacterial GPs and lays a foundation for future exploration of microbiome-mediated metabolic interactions.

Structural and mechanistic diversity of glycogen phosphorylases from gut bacteria.,Shobu K, Takai M, Tanino H, Fukuda Y, Inoue T Proc Natl Acad Sci U S A. 2026 Feb 17;123(7):e2518513123. doi: , 10.1073/pnas.2518513123. Epub 2026 Feb 9. PMID:41662519<ref>PMID:41662519</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9uoe" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Fukuda Y]]
[[Category: Inoue T]]
[[Category: Takai M]]