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| | ==CELLOBIOHYDROLASE CEL7A (E223S, A224H, L225V, T226A, D262G) MUTANT== | | ==CELLOBIOHYDROLASE CEL7A (E223S, A224H, L225V, T226A, D262G) MUTANT== |
| - | <StructureSection load='1egn' size='340' side='right' caption='[[1egn]], [[Resolution|resolution]] 1.60Å' scene=''> | + | <StructureSection load='1egn' size='340' side='right'caption='[[1egn]], [[Resolution|resolution]] 1.60Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1egn]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Trichoderma_reesei Trichoderma reesei]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EGN OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1EGN FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1egn]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Trichoderma_reesei Trichoderma reesei]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EGN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EGN FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></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]] 1.6Å</td></tr> |
| - | <tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4cel|4cel]], [[7cel|7cel]], [[1ek7|1ek7]], [[1dy4|1dy4]], [[1i5m|1i5m]]</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=1egn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1egn OCA], [https://pdbe.org/1egn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1egn RCSB], [https://www.ebi.ac.uk/pdbsum/1egn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1egn ProSAT]</span></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 Cellulose 1,4-beta-cellobiosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.91 3.2.1.91] </span></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=1egn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1egn OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1egn RCSB], [http://www.ebi.ac.uk/pdbsum/1egn PDBsum]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/GUX1_TRIRE GUX1_TRIRE]] 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/GUX1_HYPJE GUX1_HYPJE] 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/eg/1egn_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/eg/1egn_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> |
| - | </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]. | + | </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=1egn ConSurf]. |
| | <div style="clear:both"></div> | | <div style="clear:both"></div> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
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| | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| | </div> | | </div> |
| | + | <div class="pdbe-citations 1egn" style="background-color:#fffaf0;"></div> |
| | | | |
| | ==See Also== | | ==See Also== |
| - | *[[Cellobiohydrolase|Cellobiohydrolase]] | + | *[[Cellobiohydrolase 3D structures|Cellobiohydrolase 3D structures]] |
| - | *[[Glucanase|Glucanase]] | + | *[[Glucanase 3D structures|Glucanase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Cellulose 1,4-beta-cellobiosidase]] | + | [[Category: Large Structures]] |
| | [[Category: Trichoderma reesei]] | | [[Category: Trichoderma reesei]] |
| - | [[Category: Harris, M]] | + | [[Category: Harris M]] |
| - | [[Category: Jones, T A]] | + | [[Category: Jones TA]] |
| - | [[Category: Stahlberg, J]] | + | [[Category: Stahlberg J]] |
| - | [[Category: Cellulase]]
| + | |
| - | [[Category: Cellulose degradation]]
| + | |
| - | [[Category: Glycoprotein]]
| + | |
| - | [[Category: Glycosidase]]
| + | |
| - | [[Category: Glycosylated protein]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Ph-mutant]]
| + | |
| Structural highlights
Function
GUX1_HYPJE 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
The crystal structures of Family 7 glycohydrolases suggest that a histidine residue near the acid/base catalyst could account for the higher pH optimum of the Humicola insolens endoglucanase Cel7B, than the corresponding Trichoderma reesei enzymes. Modelling studies indicated that introduction of histidine at the homologous position in T. reesei Cel7A (Ala(224)) required additional changes to accommodate the bulkier histidine side chain. X-ray crystallography of the catalytic domain of the E223S/A224H/L225V/T226A/D262G mutant reveals that major differences from the wild-type are confined to the mutations themselves. The introduced histidine residue is in plane with its counterpart in H. insolens Cel7B, but is 1.0 A (=0.1 nm) closer to the acid/base Glu(217) residue, with a 3.1 A contact between N(epsilon2) and O(epsilon1). The pH variation of k(cat)/K(m) for 3,4-dinitrophenyl lactoside hydrolysis was accurately bell-shaped for both wild-type and mutant, with pK(1) shifting from 2.22+/-0.03 in the wild-type to 3.19+/-0.03 in the mutant, and pK(2) shifting from 5.99+/-0.02 to 6.78+/-0.02. With this poor substrate, the ionizations probably represent those of the free enzyme. The relative k(cat) for 2-chloro-4-nitrophenyl lactoside showed similar behaviour. The shift in the mutant pH optimum was associated with lower k(cat)/K(m) values for both lactosides and cellobiosides, and a marginally lower stability. However, k(cat) values for cellobiosides are higher for the mutant. This we attribute to reduced non-productive binding in the +1 and +2 subsites; inhibition by cellobiose is certainly relieved in the mutant. The weaker binding of cellobiose is due to the loss of two water-mediated hydrogen bonds.
Engineering of a glycosidase Family 7 cellobiohydrolase to more alkaline pH optimum: the pH behaviour of Trichoderma reesei Cel7A and its E223S/ A224H/L225V/T226A/D262G mutant.,Becker D, Braet C, Brumer H 3rd, Claeyssens M, Divne C, Fagerstrom BR, Harris M, Jones TA, Kleywegt GJ, Koivula A, Mahdi S, Piens K, Sinnott ML, Stahlberg J, Teeri TT, Underwood M, Wohlfahrt G Biochem J. 2001 May 15;356(Pt 1):19-30. PMID:11336632[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Becker D, Braet C, Brumer H 3rd, Claeyssens M, Divne C, Fagerstrom BR, Harris M, Jones TA, Kleywegt GJ, Koivula A, Mahdi S, Piens K, Sinnott ML, Stahlberg J, Teeri TT, Underwood M, Wohlfahrt G. Engineering of a glycosidase Family 7 cellobiohydrolase to more alkaline pH optimum: the pH behaviour of Trichoderma reesei Cel7A and its E223S/ A224H/L225V/T226A/D262G mutant. Biochem J. 2001 May 15;356(Pt 1):19-30. PMID:11336632
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