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| | ==Active-site mutant of potato endo-1,3-beta-glucanase in complex with laminaratriose== | | ==Active-site mutant of potato endo-1,3-beta-glucanase in complex with laminaratriose== |
| - | <StructureSection load='4gzi' size='340' side='right' caption='[[4gzi]], [[Resolution|resolution]] 1.68Å' scene=''> | + | <StructureSection load='4gzi' size='340' side='right'caption='[[4gzi]], [[Resolution|resolution]] 1.68Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4gzi]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Potato Potato]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GZI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4GZI FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4gzi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Solanum_tuberosum Solanum tuberosum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GZI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GZI FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene></td></tr> | + | </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></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3ur7|3ur7]], [[3ur8|3ur8]], [[1ghs|1ghs]], [[2cyg|2cyg]], [[3em5|3em5]], [[3f55|3f55]], [[4gzj|4gzj]]</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=4gzi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gzi OCA], [https://pdbe.org/4gzi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gzi RCSB], [https://www.ebi.ac.uk/pdbsum/4gzi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gzi ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">gluB20-2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4113 Potato])</td></tr>
| + | |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glucan_endo-1,3-beta-D-glucosidase Glucan endo-1,3-beta-D-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.39 3.2.1.39] </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=4gzi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gzi OCA], [http://pdbe.org/4gzi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4gzi RCSB], [http://www.ebi.ac.uk/pdbsum/4gzi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4gzi ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/Q70C53_SOLTU Q70C53_SOLTU] |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 4gzi" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 4gzi" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Beta-glucosidase 3D structures|Beta-glucosidase 3D structures]] |
| | + | *[[Glucanase 3D structures|Glucanase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Glucan endo-1,3-beta-D-glucosidase]] | + | [[Category: Large Structures]] |
| - | [[Category: Potato]] | + | [[Category: Solanum tuberosum]] |
| - | [[Category: Hennig, J]] | + | [[Category: Hennig J]] |
| - | [[Category: Jaskolski, M]] | + | [[Category: Jaskolski M]] |
| - | [[Category: Witek, K]] | + | [[Category: Witek K]] |
| - | [[Category: Wojtkowiak, A]] | + | [[Category: Wojtkowiak A]] |
| - | [[Category: Carbohydrate/sugar binding]]
| + | |
| - | [[Category: Catalytic nucleophile mutation]]
| + | |
| - | [[Category: Gh17 family]]
| + | |
| - | [[Category: Glucoside hydrolase]]
| + | |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Laminaratriose]]
| + | |
| - | [[Category: Tim barrel]]
| + | |
| Structural highlights
Function
Q70C53_SOLTU
Publication Abstract from PubMed
Plant endo-1,3-beta-glucanases are involved in important physiological processes such as defence mechanisms, cell division and flowering. They hydrolyze (1-->3)-beta-glucans, with very limited activity towards mixed (1-->3,1-->4)-beta-glucans and branched (1-->3,1-->6)-beta-glucans. Here, crystal structures of the potato (Solanum tuberosum) endo-1,3-beta-glucanase GLUB20-2 with the nucleophilic Glu259 residue substituted by alanine (E259A) are reported. Despite this active-site mutation, the protein retained residual endoglucanase activity and when incubated in the crystallization buffer with a linear hexameric substrate derived from (1-->3)-beta-glucan (laminarahexose) cleaved it in two different ways, generating trisaccharides and tetrasaccharides, as confirmed by mass spectrometry. The trisaccharide (laminaratriose) shows higher binding affinity and was found to fully occupy the -1, -2 and -3 sites of the active-site cleft, even at a low molar excess of the substrate. At elevated substrate concentration the tetrasaccharide molecule (laminaratetrose) also occupies the active site, spanning the opposite sites +1, +2, +3 and +4 of the cleft. These are the first crystal structures of a plant glycoside hydrolase family 17 (GH17) member to reveal the protein-saccharide interactions and were determined at resolutions of 1.68 and 1.55 A, respectively. The geometry of the active-site cleft clearly precludes any (1-->4)-beta-glucan topology at the subsites from -3 to +4 and could possibly accommodate beta-1,6-branching only at subsites +1 and +2. The glucose units at subsites -1 and -2 interact with highly conserved protein residues. In contrast, subsites -3, +3 and +4 are variable, suggesting that the mode of glucose binding at these sites may vary between different plant endo-1,3-beta-glucanases. Low substrate affinity is observed at subsites +1 and +2, as manifested by disorder of the glycosyl units there.
Structures of an active-site mutant of a plant 1,3-beta-glucanase in complex with oligosaccharide products of hydrolysis.,Wojtkowiak A, Witek K, Hennig J, Jaskolski M Acta Crystallogr D Biol Crystallogr. 2013 Jan;69(Pt 1):52-62. doi:, 10.1107/S0907444912042175. Epub 2012 Dec 20. PMID:23275163[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Wojtkowiak A, Witek K, Hennig J, Jaskolski M. Structures of an active-site mutant of a plant 1,3-beta-glucanase in complex with oligosaccharide products of hydrolysis. Acta Crystallogr D Biol Crystallogr. 2013 Jan;69(Pt 1):52-62. doi:, 10.1107/S0907444912042175. Epub 2012 Dec 20. PMID:23275163 doi:http://dx.doi.org/10.1107/S0907444912042175
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