View source for 1kck


==Bacillus circulans strain 251 Cyclodextrin glycosyl transferase mutant N193G==
<StructureSection load='1kck' size='340' side='right'caption='[[1kck]], [[Resolution|resolution]] 2.43&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kck]] 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=1KCK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KCK 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]] 2.43&#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>, <scene name='pdbligand=PRD_900065:beta-maltotriose'>PRD_900065</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=1kck FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kck OCA], [https://pdbe.org/1kck PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kck RCSB], [https://www.ebi.ac.uk/pdbsum/1kck PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kck 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/kc/1kck_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=1kck ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
Cyclodextrin-glycosyltransferase (CGTase) catalyzes the formation of alpha-, beta-, and gamma-cyclodextrins (cyclic alpha-(1,4)-linked oligosaccharides of 6, 7, or 8 glucose residues, respectively) from starch. Nine substrate binding subsites were observed in an x-ray structure of the CGTase from Bacillus circulans strain 251 complexed with a maltononaose substrate. Subsite -6 is conserved in CGTases, suggesting its importance for the reactions catalyzed by the enzyme. To investigate this in detail, we made six mutant CGTases (Y167F, G179L, G180L, N193G, N193L, and G179L/G180L). All subsite -6 mutants had decreased k(cat) values for beta-cyclodextrin formation, as well as for the disproportionation and coupling reactions, but not for hydrolysis. Especially G179L, G180L, and G179L/G180L affected the transglycosylation activities, most prominently for the coupling reactions. The results demonstrate that (i) subsite -6 is important for all three CGTase-catalyzed transglycosylation reactions, (ii) Gly-180 is conserved because of its importance for the circularization of the linear substrates, (iii) it is possible to independently change cyclization and coupling activities, and (iv) substrate interactions at subsite -6 activate the enzyme in catalysis via an induced-fit mechanism. This article provides for the first time definite biochemical evidence for such an induced-fit mechanism in the alpha-amylase family.

The remote substrate binding subsite -6 in cyclodextrin-glycosyltransferase controls the transferase activity of the enzyme via an induced-fit mechanism.,Leemhuis H, Uitdehaag JC, Rozeboom HJ, Dijkstra BW, Dijkhuizen L J Biol Chem. 2002 Jan 11;277(2):1113-9. Epub 2001 Nov 5. PMID:11696539<ref>PMID:11696539</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 1kck" 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: Rozeboom HJ]]
[[Category: Uitdehaag JCM]]