View source for 7dkt


==Crystal structure of TxGH116 E441A nucleophile mutant from Thermoanaerobacterium xylanolyticum with alpha-glucosyl fluoride==
<StructureSection load='7dkt' size='340' side='right'caption='[[7dkt]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7dkt]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermoanaerobacterium_xylanolyticum_LX-11 Thermoanaerobacterium xylanolyticum LX-11]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7DKT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7DKT 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]] 1.65&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLF:1-FLUORO-ALPHA-1-DEOXY-D-GLUCOSE'>GLF</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</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=7dkt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7dkt OCA], [https://pdbe.org/7dkt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7dkt RCSB], [https://www.ebi.ac.uk/pdbsum/7dkt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7dkt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/F6BL85_THEXL F6BL85_THEXL] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Glycosynthases are glycoside hydrolase mutants that can synthesize oligosaccharides or glycosides from an inverted donor without hydrolysis of the products. Although glycosynthases have been characterized from a variety of glycoside hydrolase (GH) families, family GH116 glycosynthases have yet to be reported. We produced the Thermoanaerobacterium xylanolyticum TxGH116 nucleophile mutants E441D, E441G, E441Q and E441S and compared their glycosynthase activities to the previously generated E441A mutant. The TxGH116 E441G and E441S mutants exhibited highest glycosynthase activity to transfer glucose from alpha-fluoroglucoside (alpha-GlcF) to cellobiose acceptor, while E441D had low but significant activity as well. The E441G, E441S and E441A variants showed broad specificity for alpha-glycosyl fluoride donors and p-nitrophenyl glycoside acceptors. The structure of the TxGH116 E441A mutant with alpha-GlcF provided the donor substrate complex, while soaking of the TxGH116 E441G mutant with alpha-GlcF resulted in cellooligosaccharides extending from the +1 subsite out of the active site, with glycerol in the -1 subsite. Soaking of E441A or E441G with cellobiose or cellotriose gave similar acceptor substrate complexes with the nonreducing glucosyl residue in the +1 subsite. Combining structures with the ligands from the TxGH116 E441A with alpha-GlcF crystals with that of E441A or E441G with cellobiose provides a plausible structure of the catalytic ternary complex, which places the nonreducing glucosyl residue O4 2.5 A from the anomeric carbon of alpha-GlcF, thereby explaining its apparent preference for production of beta-1,4-linked oligosaccharides. This functional and structural characterization provides the background for development of GH116 glycosynthases for synthesis of oligosaccharides and glycosides of interest.

Structural basis for transglycosylation in glycoside hydrolase family GH116 glycosynthases.,Pengthaisong S, Hua Y, Ketudat Cairns JR Arch Biochem Biophys. 2021 Jul 30;706:108924. doi: 10.1016/j.abb.2021.108924., Epub 2021 May 18. PMID:34019851<ref>PMID:34019851</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7dkt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Beta-glucosidase 3D structures|Beta-glucosidase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Thermoanaerobacterium xylanolyticum LX-11]]
[[Category: Ketudat Cairns JR]]
[[Category: Pengthaisong S]]