View source for 1mqp


==THE CRYSTAL STRUCTURE OF ALPHA-D-GLUCURONIDASE FROM BACILLUS STEAROTHERMOPHILUS T-6==
<StructureSection load='1mqp' size='340' side='right'caption='[[1mqp]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1mqp]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Geobacillus_stearothermophilus Geobacillus stearothermophilus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MQP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MQP 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=1mqp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mqp OCA], [https://pdbe.org/1mqp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1mqp RCSB], [https://www.ebi.ac.uk/pdbsum/1mqp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1mqp ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/AGUA_GEOSE AGUA_GEOSE] Alpha-glucuronidase involved in the hydrolysis of xylan, a major structural heterogeneous polysaccharide found in plant biomass representing the second most abundant polysaccharide in the biosphere, after cellulose. It catalyzes the cleavage of alpha-1,2-glycosidic bond of the 4-O-methyl-D-glucuronic acid side chain of xylan and releases 4-O-methylglucuronic acid from xylan.<ref>PMID:11358519</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/mq/1mqp_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1mqp ConSurf].
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<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Alpha-glucuronidases cleave the alpha-1,2-glycosidic bond between 4-O-methyl-d-glucuronic acid and short xylooligomers as part of the hemicellulose degradation system. To date, all of the alpha-glucuronidases are classified as family 67 glycosidases, which catalyze the hydrolysis via the investing mechanism. Here we describe several high resolution crystal structures of the alpha-glucuronidase (AguA) from Geobacillus stearothermophilus, in complex with its substrate and products. In the complex of AguA with the intact substrate, the 4-O-methyl-d-glucuronic acid sugar ring is distorted into a half-chair conformation, which is closer to the planar conformation required for the oxocarbenium ion-like transition state structure. In the active site, a water molecule is coordinated between two carboxylic acids, in an appropriate position to act as a nucleophile. From the structural data it is likely that two carboxylic acids, Asp(364) and Glu(392), activate together the nucleophilic water molecule. The loop carrying the catalytic general acid Glu(285) cannot be resolved in some of the structures but could be visualized in its "open" and "closed" (catalytic) conformations in other structures. The protonated state of Glu(285) is presumably stabilized by its proximity to the negative charge of the substrate, representing a new variation of substrate-assisted catalysis mechanism.

Crystal structures of Geobacillus stearothermophilus alpha-glucuronidase complexed with its substrate and products: mechanistic implications.,Golan G, Shallom D, Teplitsky A, Zaide G, Shulami S, Baasov T, Stojanoff V, Thompson A, Shoham Y, Shoham G J Biol Chem. 2004 Jan 23;279(4):3014-24. Epub 2003 Oct 22. PMID:14573597<ref>PMID:14573597</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 1mqp" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glucuronisidase 3D structures|Glucuronisidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Geobacillus stearothermophilus]]
[[Category: Large Structures]]
[[Category: Baasov T]]
[[Category: Golan G]]
[[Category: Shallom D]]
[[Category: Shoham G]]
[[Category: Shoham Y]]
[[Category: Shulami S]]
[[Category: Stojanoff V]]
[[Category: Teplitsky A]]
[[Category: Thompson A]]
[[Category: Zaide G]]