View source for 1dtu


==BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE: A MUTANT Y89D/S146P COMPLEXED TO AN HEXASACCHARIDE INHIBITOR==
<StructureSection load='1dtu' size='340' side='right'caption='[[1dtu]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1dtu]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Niallia_circulans Niallia circulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1DTU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1DTU 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADH:1-AMINO-2,3-DIHYDROXY-5-HYDROXYMETHYL+CYCLOHEX-5-ENE'>ADH</scene>, <scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=G6D:6-DEOXY-ALPHA-D-GLUCOSE'>G6D</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900001:alpha-maltose'>PRD_900001</scene>, <scene name='pdbligand=PRD_900009:alpha-maltotriose'>PRD_900009</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=1dtu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1dtu OCA], [https://pdbe.org/1dtu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1dtu RCSB], [https://www.ebi.ac.uk/pdbsum/1dtu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1dtu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CDGT2_NIACI CDGT2_NIACI] 
== 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/dt/1dtu_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=1dtu ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Cyclodextrin glycosyltransferases (CGTase) (EC 2.4.1.19) are extracellular bacterial enzymes that generate cyclodextrins from starch. All known CGTases produce mixtures of alpha, beta, and gamma-cyclodextrins. A maltononaose inhibitor bound to the active site of the CGTase from Bacillus circulans strain 251 revealed sugar binding subsites, distant from the catalytic residues, which have been proposed to be involved in the cyclodextrin size specificity of these enzymes. To probe the importance of these distant substrate binding subsites for the alpha, beta, and gamma-cyclodextrin product ratios of the various CGTases, we have constructed three single and one double mutant, Y89G, Y89D, S146P and Y89D/S146P, using site-directed mutagenesis. The mutations affected the cyclization, coupling; disproportionation and hydrolyzing reactions of the enzyme. The double mutant Y89D/S146P showed a twofold increase in the production of alpha-cyclodextrin from starch. This mutant protein was crystallized and its X-ray structure, in a complex with a maltohexaose inhibitor, was determined at 2.4 A resolution. The bound maltohexaose molecule displayed a binding different from the maltononaose inhibitor, allowing rationalization of the observed change in product specificity. Hydrogen bonds (S146) and hydrophobic contacts (Y89) appear to contribute strongly to the size of cyclodextrin products formed and thus to CGTase product specificity. Changes in sugar binding subsites -3 and -7 thus result in mutant proteins with changed cyclodextrin production specificity.

Rational design of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 to increase alpha-cyclodextrin production.,van der Veen BA, Uitdehaag JC, Penninga D, van Alebeek GJ, Smith LM, Dijkstra BW, Dijkhuizen L J Mol Biol. 2000 Mar 3;296(4):1027-38. PMID:10686101<ref>PMID:10686101</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 1dtu" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glycosyltransferase 3D structures|Glycosyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Niallia circulans]]
[[Category: Dijkstra BW]]
[[Category: Kalk KH]]
[[Category: Uitdehaag JCM]]