View source for 1eo5


==Bacillus circulans strain 251 cyclodextrin glycosyltransferase in complex with maltoheptaose==
<StructureSection load='1eo5' size='340' side='right'caption='[[1eo5]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1eo5]] 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=1EO5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EO5 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&#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=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=PRD_900009:alpha-maltotriose'>PRD_900009</scene>, <scene name='pdbligand=PRD_900010:alpha-maltotetraose'>PRD_900010</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=1eo5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eo5 OCA], [https://pdbe.org/1eo5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1eo5 RCSB], [https://www.ebi.ac.uk/pdbsum/1eo5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1eo5 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/eo/1eo5_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=1eo5 ConSurf].
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== Publication Abstract from PubMed ==
The enzymes from the alpha-amylase family all share a similar alpha-retaining catalytic mechanism but can have different reaction and product specificities. One family member, cyclodextrin glycosyltransferase (CGTase), has an uncommonly high transglycosylation activity and is able to form cyclodextrins. We have determined the 2.0 and 2.5 A X-ray structures of E257A/D229A CGTase in complex with maltoheptaose and maltohexaose. Both sugars are bound at the donor subsites of the active site and the acceptor subsites are empty. These structures mimic a reaction stage in which a covalent enzyme-sugar intermediate awaits binding of an acceptor molecule. Comparison of these structures with CGTase-substrate and CGTase-product complexes reveals three different conformational states for the CGTase active site that are characterized by different orientations of the centrally located residue Tyr 195. In the maltoheptaose and maltohexaose-complexed conformation, CGTase hinders binding of an acceptor sugar at subsite +1, which suggests an induced-fit mechanism that could explain the transglycosylation activity of CGTase. In addition, the maltoheptaose and maltohexaose complexes give insight into the cyclodextrin size specificity of CGTases, since they precede alpha-cyclodextrin (six glucoses) and beta-cyclodextrin (seven glucoses) formation, respectively. Both ligands show conformational differences at specific sugar binding subsites, suggesting that these determine cyclodextrin product size specificity, which is confirmed by site-directed mutagenesis experiments.

Structures of maltohexaose and maltoheptaose bound at the donor sites of cyclodextrin glycosyltransferase give insight into the mechanisms of transglycosylation activity and cyclodextrin size specificity.,Uitdehaag JC, van Alebeek GJ, van Der Veen BA, Dijkhuizen L, Dijkstra BW Biochemistry. 2000 Jul 4;39(26):7772-80. PMID:10869182<ref>PMID:10869182</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 1eo5" 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: Uitdehaag JCM]]