View source for 7v0j


==Crystal structure of a CelR catalytic domain active site mutant with bound cellobiose product==
<StructureSection load='7v0j' size='340' side='right'caption='[[7v0j]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7v0j]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Acetivibrio_thermocellus Acetivibrio thermocellus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7V0J OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7V0J 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</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=7v0j FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7v0j OCA], [https://pdbe.org/7v0j PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7v0j RCSB], [https://www.ebi.ac.uk/pdbsum/7v0j PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7v0j ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A3DCY5_ACET2 A3DCY5_ACET2] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Enzymatic deconstruction of lignocellulosic biomass is crucial to establishment of the renewable biofuel and bioproduct economy. Better understanding of these enzymes, including their catalytic and binding domains, and other features offer potential avenues for improvement. Glycoside hydrolase family 9 (GH9) enzymes are attractive targets because they have members that exhibit exo- and endo-cellulytic activity, processivity of reaction, and thermostability. This study examines a GH9 from Acetovibrio thermocellus ATCC 27405, AtCelR containing a catalytic domain and a carbohydrate binding module (CBM3c). Crystal structures of the enzyme without substrate, bound to cellohexaose (substrate) or cellobiose (product) show the positioning of ligands to calcium and adjacent residues in the catalytic domain that may contribute to substrate binding and facilitate product release. We also investigated the properties of the enzyme engineered to contain an additional carbohydrate binding module (CBM3a). Relative to the catalytic domain alone, CBM3a gave improved binding for Avicel (a crystalline form of cellulose) and catalytic efficiency (k(cat)/K(M)) was improved 40x with both CBM3c and CBM3a present. However, because of the molecular weight added by CBM3a, the specific activity of the engineered enzyme was not increased relative to the native construct consisting of only the catalytic and CBM3c domains. This work provides new insight into a potential role of the conserved calcium in the catalytic domain and identifies contributions and limitations of domain engineering for AtCelR and perhaps other GH9 enzymes.

Contribution of calcium ligands in substrate binding and product release in the Acetovibrio thermocellus glycoside hydrolase family 9 cellulase CelR.,Kuch NJ, Kutschke ME, Parker A, Bingman CA, Fox BG J Biol Chem. 2023 Mar 27:104655. doi: 10.1016/j.jbc.2023.104655. PMID:36990218<ref>PMID:36990218</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7v0j" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Acetivibrio thermocellus]]
[[Category: Large Structures]]
[[Category: Bingman CA]]
[[Category: Fox BG]]
[[Category: Kuch N]]
[[Category: Kutsche ME]]
[[Category: Parker A]]
[[Category: Smith RW]]