1eo7: Difference between revisions
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[[Image: | ==BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE IN COMPLEX WITH MALTOHEXAOSE== | ||
<StructureSection load='1eo7' size='340' side='right' caption='[[1eo7]], [[Resolution|resolution]] 2.48Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1eo7]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bacillus_circulans Bacillus circulans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EO7 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1EO7 FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1cdg|1cdg]], [[1eo5|1eo5]], [[1cxf|1cxf]], [[1cxk|1cxk]], [[1cxl|1cxl]], [[1d3c|1d3c]]</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Cyclomaltodextrin_glucanotransferase Cyclomaltodextrin glucanotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.19 2.4.1.19] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1eo7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1eo7 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1eo7 RCSB], [http://www.ebi.ac.uk/pdbsum/1eo7 PDBsum]</span></td></tr> | |||
<table> | |||
== 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/1eo7_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/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== 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®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Glycosyltransferase|Glycosyltransferase]] | *[[Glycosyltransferase|Glycosyltransferase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Bacillus circulans]] | [[Category: Bacillus circulans]] | ||
[[Category: Cyclomaltodextrin glucanotransferase]] | [[Category: Cyclomaltodextrin glucanotransferase]] | ||
Revision as of 14:12, 24 September 2014
BACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE IN COMPLEX WITH MALTOHEXAOSEBACILLUS CIRCULANS STRAIN 251 CYCLODEXTRIN GLYCOSYLTRANSFERASE IN COMPLEX WITH MALTOHEXAOSE
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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