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| | ==CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF THE BETA-1,4-GLYCANASE CEX FROM CELLULOMONAS FIMI== | | ==CRYSTAL STRUCTURE OF THE CATALYTIC DOMAIN OF THE BETA-1,4-GLYCANASE CEX FROM CELLULOMONAS FIMI== |
| - | <StructureSection load='2exo' size='340' side='right' caption='[[2exo]], [[Resolution|resolution]] 1.80Å' scene=''> | + | <StructureSection load='2exo' size='340' side='right'caption='[[2exo]], [[Resolution|resolution]] 1.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2exo]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacterium_fimi"_mcbeth_and_scales_1913 "bacterium fimi" mcbeth and scales 1913]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EXO OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2EXO FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2exo]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Cellulomonas_fimi Cellulomonas fimi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EXO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2EXO FirstGlance]. <br> |
| - | </td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Cellulose_1,4-beta-cellobiosidase_(non-reducing_end) Cellulose 1,4-beta-cellobiosidase (non-reducing end)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] </span></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.8Å</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2exo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2exo OCA], [http://pdbe.org/2exo PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2exo RCSB], [http://www.ebi.ac.uk/pdbsum/2exo PDBsum]</span></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=2exo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2exo OCA], [https://pdbe.org/2exo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2exo RCSB], [https://www.ebi.ac.uk/pdbsum/2exo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2exo ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/GUX_CELFI GUX_CELFI]] Hydrolyzes both cellulose and xylan. Has also weak endoglucanase activity. The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose. | + | [https://www.uniprot.org/uniprot/GUX_CELFI GUX_CELFI] Hydrolyzes both cellulose and xylan. Has also weak endoglucanase activity. The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ex/2exo_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ex/2exo_consurf.spt"</scriptWhenChecked> |
| - | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
| | </jmolCheckbox> | | </jmolCheckbox> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacterium fimi mcbeth and scales 1913]] | + | [[Category: Cellulomonas fimi]] |
| - | [[Category: Gilkes, N R]] | + | [[Category: Large Structures]] |
| - | [[Category: Rose, D R]] | + | [[Category: Gilkes NR]] |
| - | [[Category: White, A]] | + | [[Category: Rose DR]] |
| - | [[Category: Withers, S G]] | + | [[Category: White A]] |
| | + | [[Category: Withers SG]] |
| Structural highlights
Function
GUX_CELFI Hydrolyzes both cellulose and xylan. Has also weak endoglucanase activity. The biological conversion of cellulose to glucose generally requires three types of hydrolytic enzymes: (1) Endoglucanases which cut internal beta-1,4-glucosidic bonds; (2) Exocellobiohydrolases that cut the dissaccharide cellobiose from the non-reducing end of the cellulose polymer chain; (3) Beta-1,4-glucosidases which hydrolyze the cellobiose and other short cello-oligosaccharides to glucose.
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 PubMed
beta-1,4-Glycanases, principally cellulases and xylanases, are responsible for the hydrolysis of plant biomass. The bifunctional beta-1,4-xylanase/glucanase Cex from the bacterium Cellulomonas fimi, one of a large family of cellulases/xylanases, depolymerizes oligosaccharides and releases a disaccharide unit from the substrate nonreducing end. Hydrolysis occurs with net retention of the anomeric configuration of the sugar through a double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. The active site nucleophile, Glu233, has been unambiguously identified by trapping of such an intermediate [Tull et al. (1991) J. Biol. Chem. 266, 15621-15625] and the acid/base catalyst, Glu127, by detailed kinetic analysis of mutants [MacLeod et al. (1994) Biochemistry 33, 6371-6376]. However, little is known about the enzyme's overall folding and its active site architecture. We report here the high-resolution crystal structure of the catalytic domain of Cex. The atomic structure refinement results in a model that includes 2400 protein atoms and 45 water molecules, with an R-factor of 0.217 for data extending to 1.8-A resolution. The protein forms an eight-parallel-stranded alpha/beta-barrel, which is a novel folding pattern for a microbial beta-glycanase. The active site, inferred from the location of Glu233, Glu127, and other conserved residues, is an open cleft on the carboxy-terminal end of the alpha/beta-barrel. An extensive hydrogen-bonding network stabilizes the ionization states of the key residues; in particular, the Asp235-His205-Glu233 hydrogen-bonding network may play a role in modulating the ionization state of Glu233 and in controlling local charge balance during the reaction.
Crystal structure of the catalytic domain of the beta-1,4-glycanase cex from Cellulomonas fimi.,White A, Withers SG, Gilkes NR, Rose DR Biochemistry. 1994 Oct 25;33(42):12546-52. PMID:7918478[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ White A, Withers SG, Gilkes NR, Rose DR. Crystal structure of the catalytic domain of the beta-1,4-glycanase cex from Cellulomonas fimi. Biochemistry. 1994 Oct 25;33(42):12546-52. PMID:7918478
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