View source for 1lq2


==Crystal structure of barley beta-D-glucan glucohydrolase isoenzyme Exo1 in complex with gluco-phenylimidazole==
<StructureSection load='1lq2' size='340' side='right'caption='[[1lq2]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1lq2]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Hordeum_vulgare Hordeum vulgare]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LQ2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1LQ2 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=FUC:ALPHA-L-FUCOSE'>FUC</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=IDD:(5R,6R,7S,8S)-5-(HYDROXYMETHYL)-2-PHENYL-5,6,7,8-TETRAHYDROIMIDAZO[1,2-A]PYRIDINE-6,7,8-TRIOL'>IDD</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=1lq2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1lq2 OCA], [https://pdbe.org/1lq2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1lq2 RCSB], [https://www.ebi.ac.uk/pdbsum/1lq2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1lq2 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q9XEI3_HORVV Q9XEI3_HORVV] 
== 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/lq/1lq2_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1lq2 ConSurf].
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== Publication Abstract from PubMed ==
Glucophenylimidazole (PheGlcIm), a tetrahydroimidazopyridine-type inhibitor and 4H3 conformer mimic of a glucoside, binds very tightly to a barley beta-d-glucan glucohydrolase, with a Ki constant of 2 x 10(-9) m and a DeltaG of 51 kJ mol(-1). PheGlcIm binds to the barley beta-d-glucan glucohydrolase approximately 2 x 10(5) times tighter than laminarin, which is the best non-synthetic ground-state substrate found so far for this enzyme, 10(6) times tighter than 4-nitrophenyl beta-d-glucopyranoside, and 2 x 10(7) tighter than glucose. The three-dimensional structure of the beta-d-glucan glucohydrolase with bound PheGlcIm indicates that the complex resembles a hypothetical transition state during the hydrolytic cycle, that the enzyme derives substrate binding energy from the "aglycone" portion of the ligand, and that it also reveals an anti-protonation trajectory for hydrolysis. Continuous electron densities at the 1.6 sigma level form between the three active site residues Asp95, His207, and Asp285, and the C6OH, C7OH, C8OH, and C9OH groups of PheGlcIm. These electron densities correspond to the most favorable interactions in the three-dimensional structure of the beta-d-glucan glucohydrolase-PheGlcIm complex and indicate atomic distances equal to or less than 2.55 A. The crystallographic data were corroborated with ab initio molecular orbital calculations. The data indicate that the 4E conformation of the glucose part of PheGlcIm is critical for tight binding and provide the first evidence for probable substrate distortion during catalysis by this enzyme.

Three-dimensional structure of the barley beta-D-glucan glucohydrolase in complex with a transition state mimic.,Hrmova M, De Gori R, Smith BJ, Vasella A, Varghese JN, Fincher GB J Biol Chem. 2004 Feb 6;279(6):4970-80. Epub 2003 Nov 3. PMID:14597633<ref>PMID:14597633</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 1lq2" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Hordeum vulgare]]
[[Category: Large Structures]]
[[Category: De Gori R]]
[[Category: Fincher GB]]
[[Category: Hrmova M]]
[[Category: Smith BJ]]
[[Category: Varghese JN]]
[[Category: Vasella A]]