View source for 3wem


==Sugar beet alpha-glucosidase with acarviosyl-maltotetraose==
<StructureSection load='3wem' size='340' side='right'caption='[[3wem]], [[Resolution|resolution]] 2.59&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3wem]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Beta_vulgaris Beta vulgaris]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3WEM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3WEM 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]] 2.591&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=AC1:6-METHYL-5-(4,5,6-TRIHYDROXY-3-HYDROXYMETHYL-CYCLOHEX-2-ENYLAMINO)-TETRAHYDRO-PYRAN-2,3,4-TRIOL'>AC1</scene>, <scene name='pdbligand=FUC:ALPHA-L-FUCOSE'>FUC</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=3wem FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3wem OCA], [https://pdbe.org/3wem PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3wem RCSB], [https://www.ebi.ac.uk/pdbsum/3wem PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3wem ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/L0N7E5_BETVU L0N7E5_BETVU] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The alpha-glucosidase from sugar beet (SBG) is an exo-type glycosidase. The enzyme has a pocket-shaped active site, but efficiently hydrolyzes longer maltooligosaccharides and soluble starch due to lower Km and higher kcat/Km for such substrates. To obtain structural insights into the mechanism governing its unique substrate specificity, a series of acarviosyl-maltooligosaccharides was employed for steady-state kinetic and structural analyses. The acarviosyl-maltooligosaccharides have a longer maltooligosaccharide moiety compared to the maltose moiety of acarbose, which is known to be the transition-state analog of alpha-glycosidases. The clear correlation obtained between logKi of the acarviosyl-maltooligosaccharides and log(Km/kcat) for hydrolysis of maltooligosaccharides suggests that the acarviosyl-maltooligosaccharides are transition state mimics. The crystal structure of the enzyme bound with acarviosyl-maltohexaose reveals that substrate binding at a distance from the active site is maintained largely by van der Waals interactions, with the four glucose residues at the reducing terminus of acarviosyl-maltohexaose retaining a left-handed single-helical conformation, as also observed in cycloamyloses and single-helical V-amyloses. The kinetic behavior and structural features suggest that the subsite structure suitable for the stable conformation of amylose lowers the Km for long-chain substrates, which in turn is responsible for higher specificity of the longer substrates.

Structural advantage of sugar beet alpha-glucosidase to stabilize the Michaelis complex with long-chain substrate.,Tagami T, Yamashita K, Okuyama M, Mori H, Yao M, Kimura A J Biol Chem. 2014 Dec 1. pii: jbc.M114.606939. PMID:25451917<ref>PMID:25451917</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3wem" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alpha-glucosidase 3D structures|Alpha-glucosidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Beta vulgaris]]
[[Category: Large Structures]]
[[Category: Kimura A]]
[[Category: Mori H]]
[[Category: Okuyama M]]
[[Category: Tagami T]]
[[Category: Yamashita K]]
[[Category: Yao M]]