View source for 8sdb


==Crystal Structure of E.Coli Branching Enzyme in complex with malto-octose==
<StructureSection load='8sdb' size='340' side='right'caption='[[8sdb]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8sdb]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8SDB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8SDB 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</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=8sdb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8sdb OCA], [https://pdbe.org/8sdb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8sdb RCSB], [https://www.ebi.ac.uk/pdbsum/8sdb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8sdb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GLGB_ECOLI GLGB_ECOLI] Catalyzes the formation of the alpha-1,6-glucosidic linkages in glycogen by scission of a 1,4-alpha-linked oligosaccharide from growing alpha-1,4-glucan chains and the subsequent attachment of the oligosaccharide to the alpha-1,6 position (By similarity).
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== Publication Abstract from PubMed ==
Glycogen is the primary storage polysaccharide in bacteria and animals. It is a glucose polymer linked by alpha-1,4 glucose linkages and branched via alpha-1,6-linkages, with the latter reaction catalyzed by branching enzymes. Both the length and dispensation of these branches are critical in defining the structure, density, and relative bioavailability of the storage polysaccharide. Key to this is the specificity of branching enzymes because they define branch length. Herein, we report the crystal structure of the maltooctaose-bound branching enzyme from the enterobacteria E. coli. The structure identifies three new malto-oligosaccharide binding sites and confirms oligosaccharide binding in seven others, bringing the total number of oligosaccharide binding sites to twelve. In addition, the structure shows distinctly different binding in previously identified site I, with a substantially longer glucan chain ordered in the binding site. Using the donor oligosaccharide chain-bound Cyanothece branching enzyme structure as a guide, binding site I was identified as the likely binding surface for the extended donor chains that the E. coli branching enzyme is known to transfer. Furthermore, the structure suggests that analogous loops in branching enzymes from a diversity of organisms are responsible for branch chain length specificity. Together, these results suggest a possible mechanism for transfer chain specificity involving some of these surface binding sites.

The Structure of Maltooctaose-Bound Escherichia coli Branching Enzyme Suggests a Mechanism for Donor Chain Specificity.,Fawaz R, Bingham C, Nayebi H, Chiou J, Gilbert L, Park SH, Geiger JH Molecules. 2023 May 27;28(11):4377. doi: 10.3390/molecules28114377. PMID:37298853<ref>PMID:37298853</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 8sdb" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Bingham CR]]
[[Category: Fawaz R]]
[[Category: Geiger JH]]
[[Category: Nayebi H]]