View source for 5gw7


==Crystal structure of the glycosynthase mutant E727A of Escherichia coli GH63 glycosidase in complex with glucose and lactose==
<StructureSection load='5gw7' size='340' side='right'caption='[[5gw7]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5gw7]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=5ca4 5ca4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5GW7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5GW7 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]] 2.2&#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>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PRD_900008:alpha-lactose'>PRD_900008</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=5gw7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5gw7 OCA], [https://pdbe.org/5gw7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5gw7 RCSB], [https://www.ebi.ac.uk/pdbsum/5gw7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5gw7 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/YGJK_ECOLI YGJK_ECOLI] Glucoside hydrolase that cleaves the alpha-1,3-glucosidic linkage in nigerose. Has very low activity towards maltooligosaccharides, soluble starch, nigerotriose, kojibiose and trehalose.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Glycoside hydrolases are divided into two groups, known as inverting and retaining enzymes, based on their hydrolytic mechanisms. Glycoside hydrolase family 63 (GH63) is composed of inverting alpha-glycosidases, which act mainly on alpha-glucosides. We previously found that Escherichia coli GH63 enzyme, YgjK, can hydrolyze 2-O-alpha-d-glucosyl-d-galactose. Two constructed glycosynthase mutants, D324N and E727A, which catalyze the transfer of a beta-glucosyl fluoride donor to galactose, lactose, and melibiose. Here, we determined the crystal structures of D324N and E727A soaked with a mixture of glucose and lactose at 1.8- and 2.1-A resolutions, respectively. Because glucose and lactose molecules are found at the active sites in both structures, it is possible that these structures mimic the enzyme-product complex of YgjK. A glucose molecule found at subsite -1 in both structures adopts an unusual 1S3 skew-boat conformation. Comparison between these structures and the previously determined enzyme-substrate complex structure reveals that the glucose pyranose ring might be distorted immediately after nucleophilic attack by a water molecule. These structures represent the first enzyme-product complex for the GH63 family, as well as the structurally-related glycosidases, and it may provide insight into the catalytic mechanism of these enzymes.

Crystal structure of the enzyme-product complex reveals sugar ring distortion during catalysis by family 63 inverting alpha-glycosidase.,Miyazaki T, Nishikawa A, Tonozuka T J Struct Biol. 2016 Sep 26. pii: S1047-8477(16)30204-0. doi:, 10.1016/j.jsb.2016.09.015. PMID:27688023<ref>PMID:27688023</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 5gw7" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Miyazaki T]]
[[Category: Tonozuka T]]