1ece: Difference between revisions
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< | ==ACIDOTHERMUS CELLULOLYTICUS ENDOCELLULASE E1 CATALYTIC DOMAIN IN COMPLEX WITH A CELLOTETRAOSE== | ||
<StructureSection load='1ece' size='340' side='right'caption='[[1ece]], [[Resolution|resolution]] 2.40Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1ece]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Acidothermus_cellulolyticus Acidothermus cellulolyticus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ECE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ECE 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]] 2.4Å</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=PRD_900011:beta-cellotetraose'>PRD_900011</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=1ece FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ece OCA], [https://pdbe.org/1ece PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ece RCSB], [https://www.ebi.ac.uk/pdbsum/1ece PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ece ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/GUN1_ACIC1 GUN1_ACIC1] Has a very high specific activity on carboxymethylcellulose. | |||
== 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/ec/1ece_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=1ece ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The crystal structure of the catalytic domain of the thermostable endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose has been solved by multiple isomorphous replacement and refined at 2.4 A resolution to an R-factor of 0.18 (Rfree = 0.24). E1cd is a member of the 4/7 superfamily of hydrolases, and as expected, its structure is an (alpha/beta)8 barrel, which constitutes a prototype for family 5-subfamily 1 cellulases. The cellotetraose molecule binds in a manner consistent with the expected Michaelis complex for the glycosylation half-reaction and reveals that all eight residues conserved in family 5 enzymes are involved in recognition of the glycosyl group attacked during cleavage. Whereas only three residues are conserved in the whole 4/7 superfamily (the Asn/Glu duo and the Glu from which the name is derived), structural comparisons show that all eight residues conserved in family 5 have functional equivalents in the other 4/7 superfamily members, strengthening the case that mechanistic details are conserved throughout the superfamily. On the basis of the structure, a detailed sequence of physical steps of the cleavage mechanism is proposed. A close approach of two key glutamate residues provides an elegant mechanism for the shift in the pKa of the acid/base for the glycosylation and deglycosylation half-reactions. Finally, purely structural based comparisons are used to show that significant differences exist in structural similarity scores resulting from different methods and suggest that caution should be exercised in interpreting such results in terms of implied evolutional relationships. | |||
Crystal structure of thermostable family 5 endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose.,Sakon J, Adney WS, Himmel ME, Thomas SR, Karplus PA Biochemistry. 1996 Aug 20;35(33):10648-60. PMID:8718854<ref>PMID:8718854</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1ece" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Glucanase 3D structures|Glucanase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
== | |||
< | |||
[[Category: Acidothermus cellulolyticus]] | [[Category: Acidothermus cellulolyticus]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Himmel | [[Category: Himmel ME]] | ||
[[Category: Karplus | [[Category: Karplus PA]] | ||
[[Category: Sakon | [[Category: Sakon J]] | ||
[[Category: Thomas | [[Category: Thomas SR]] | ||
Latest revision as of 07:29, 17 October 2024
ACIDOTHERMUS CELLULOLYTICUS ENDOCELLULASE E1 CATALYTIC DOMAIN IN COMPLEX WITH A CELLOTETRAOSEACIDOTHERMUS CELLULOLYTICUS ENDOCELLULASE E1 CATALYTIC DOMAIN IN COMPLEX WITH A CELLOTETRAOSE
Structural highlights
FunctionGUN1_ACIC1 Has a very high specific activity on carboxymethylcellulose. 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 crystal structure of the catalytic domain of the thermostable endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose has been solved by multiple isomorphous replacement and refined at 2.4 A resolution to an R-factor of 0.18 (Rfree = 0.24). E1cd is a member of the 4/7 superfamily of hydrolases, and as expected, its structure is an (alpha/beta)8 barrel, which constitutes a prototype for family 5-subfamily 1 cellulases. The cellotetraose molecule binds in a manner consistent with the expected Michaelis complex for the glycosylation half-reaction and reveals that all eight residues conserved in family 5 enzymes are involved in recognition of the glycosyl group attacked during cleavage. Whereas only three residues are conserved in the whole 4/7 superfamily (the Asn/Glu duo and the Glu from which the name is derived), structural comparisons show that all eight residues conserved in family 5 have functional equivalents in the other 4/7 superfamily members, strengthening the case that mechanistic details are conserved throughout the superfamily. On the basis of the structure, a detailed sequence of physical steps of the cleavage mechanism is proposed. A close approach of two key glutamate residues provides an elegant mechanism for the shift in the pKa of the acid/base for the glycosylation and deglycosylation half-reactions. Finally, purely structural based comparisons are used to show that significant differences exist in structural similarity scores resulting from different methods and suggest that caution should be exercised in interpreting such results in terms of implied evolutional relationships. Crystal structure of thermostable family 5 endocellulase E1 from Acidothermus cellulolyticus in complex with cellotetraose.,Sakon J, Adney WS, Himmel ME, Thomas SR, Karplus PA Biochemistry. 1996 Aug 20;35(33):10648-60. PMID:8718854[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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