View source for 1cgu


==CATALYTIC CENTER OF CYCLODEXTRIN GLYCOSYLTRANSFERASE DERIVED FROM X-RAY STRUCTURE ANALYSIS COMBINED WITH SITE-DIRECTED MUTAGENESIS==
<StructureSection load='1cgu' size='340' side='right'caption='[[1cgu]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1cgu]] 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=1CGU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1CGU 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900001:alpha-maltose'>PRD_900001</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=1cgu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1cgu OCA], [https://pdbe.org/1cgu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1cgu RCSB], [https://www.ebi.ac.uk/pdbsum/1cgu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1cgu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CDGT1_NIACI CDGT1_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/cg/1cgu_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=1cgu ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
An X-ray structure analysis of a crystal of mutant Asp229----Ala of cyclodextrin glycosyltransferase from Bacillus circulans (Ec 2.4.1.19) that had been shortly exposed to beta-cyclodextrin showed density corresponding to a maltose bound at the catalytic center. The crystal structure was refined to an R-factor of 18.7% at 2.5-A resolution. The catalytic center is defined by homology with the structurally known alpha-amylases and by the observation that mutants Asp229----Ala and Asp328----Ala are almost inactive. By model building, the density-defined maltose was extended to a full beta-cyclodextrin, which then indicated the general locations of seven subsites for glucosyl units. The catalytically competent residues Asp229, Glu257, and Asp328 are at the reducing end of the density-defined maltose. In the unligated wild-type structure, Glu257 and Asp328 form a 2.6-A hydrogen bond between their carboxylates in an arrangement that resembles those of the catalytically competent carboxylates in acid proteases. Presumably, the first catalytic step is an attack of the proton between Glu257 and Asp328 on the oxygen of the glycosidic bond.

Catalytic center of cyclodextrin glycosyltransferase derived from X-ray structure analysis combined with site-directed mutagenesis.,Klein C, Hollender J, Bender H, Schulz GE Biochemistry. 1992 Sep 22;31(37):8740-6. PMID:1390660<ref>PMID:1390660</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1cgu" style="background-color:#fffaf0;"></div>

==See Also==
*[[Glycosyltransferase 3D structures|Glycosyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Niallia circulans]]
[[Category: Bender H]]
[[Category: Hollender J]]
[[Category: Klein C]]
[[Category: Schulz GE]]