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| | ==Crystal Structures of Mutant Endo- -1,4-xylanase II Complexed with substrate (1.15 A) and Products (1.6 A)== | | ==Crystal Structures of Mutant Endo- -1,4-xylanase II Complexed with substrate (1.15 A) and Products (1.6 A)== |
| - | <StructureSection load='4hk8' size='340' side='right' caption='[[4hk8]], [[Resolution|resolution]] 1.15Å' scene=''> | + | <StructureSection load='4hk8' size='340' side='right'caption='[[4hk8]], [[Resolution|resolution]] 1.15Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[4hk8]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_13631 Atcc 13631]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HK8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4HK8 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[4hk8]] 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=4HK8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HK8 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=XYP:BETA-D-XYLOPYRANOSE'>XYP</scene></td></tr> | + | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=XYP:BETA-D-XYLOPYRANOSE'>XYP</scene></td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2dfb|2dfb]], [[4hk9|4hk9]], [[4hkl|4hkl]], [[4hko|4hko]]</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=4hk8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hk8 OCA], [https://pdbe.org/4hk8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hk8 RCSB], [https://www.ebi.ac.uk/pdbsum/4hk8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hk8 ProSAT]</span></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">xyn2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=51453 ATCC 13631])</td></tr>
| + | |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Endo-1,4-beta-xylanase Endo-1,4-beta-xylanase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.8 3.2.1.8] </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=4hk8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hk8 OCA], [http://pdbe.org/4hk8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4hk8 RCSB], [http://www.ebi.ac.uk/pdbsum/4hk8 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4hk8 ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/XYN2_HYPJR XYN2_HYPJR] Glycoside hydrolase involved in the hydrolysis of xylan, a major plant cell wall hemicellulose made up of 1,4-beta-linked D-xylopyranose residues. Catalyzes the endohydrolysis of the main-chain 1,4-beta-glycosidic bonds connecting the xylose subunits yielding various xylooligosaccharides and xylose (PubMed:1369024, Ref.5). The catalysis proceeds by a double-displacement reaction mechanism with a putative covalent glycosyl-enzyme intermediate, with retention of the anomeric configuration (PubMed:7988708). Produces xylobiose and xylose as the main degradation products (PubMed:19556747).<ref>PMID:1369024</ref> <ref>PMID:19556747</ref> <ref>PMID:7988708</ref> <ref>PMID:1369024</ref> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Atcc 13631]] | + | [[Category: Large Structures]] |
| - | [[Category: Endo-1,4-beta-xylanase]] | + | [[Category: Trichoderma reesei]] |
| - | [[Category: Coates, L]] | + | [[Category: Coates L]] |
| - | [[Category: Kovalevsky, A]] | + | [[Category: Kovalevsky A]] |
| - | [[Category: Langan, P]] | + | [[Category: Langan P]] |
| - | [[Category: Wan, Q]] | + | [[Category: Wan Q]] |
| - | [[Category: Hydrolase]]
| + | |
| - | [[Category: Induced fit mechanism]]
| + | |
| - | [[Category: Oxocarbenium ion]]
| + | |
| - | [[Category: Palm-hand motif]]
| + | |
| - | [[Category: Xylanase ii]]
| + | |
| - | [[Category: Xylohexaose]]
| + | |
| - | [[Category: Xylotriose]]
| + | |
| Structural highlights
Function
XYN2_HYPJR Glycoside hydrolase involved in the hydrolysis of xylan, a major plant cell wall hemicellulose made up of 1,4-beta-linked D-xylopyranose residues. Catalyzes the endohydrolysis of the main-chain 1,4-beta-glycosidic bonds connecting the xylose subunits yielding various xylooligosaccharides and xylose (PubMed:1369024, Ref.5). The catalysis proceeds by a double-displacement reaction mechanism with a putative covalent glycosyl-enzyme intermediate, with retention of the anomeric configuration (PubMed:7988708). Produces xylobiose and xylose as the main degradation products (PubMed:19556747).[1] [2] [3] [4]
Publication Abstract from PubMed
Xylanases catalyze the hydrolysis of plant hemicellulose xylan into oligosaccharides by cleaving the main-chain glycosidic linkages connecting xylose subunits. To study ligand binding and to understand how the pH constrains the activity of the enzyme, variants of the Trichoderma reesei xylanase were designed to either abolish its activity (E177Q) or to change its pH optimum (N44H). An E177Q-xylohexaose complex structure was obtained at 1.15 A resolution which represents a pseudo-Michaelis complex and confirmed the conformational movement of the thumb region owing to ligand binding. Co-crystallization of N44H with xylohexaose resulted in a hydrolyzed xylotriose bound in the active site. Co-crystallization of the wild-type enzyme with xylopentaose trapped an aglycone xylotriose and a transglycosylated glycone product. Replacing amino acids near Glu177 decreased the xylanase activity but increased the relative activity at alkaline pH. The substrate distortion in the E177Q-xylohexaose structure expands the possible conformational itinerary of this xylose ring during the enzyme-catalyzed xylan-hydrolysis reaction.
X-ray crystallographic studies of family 11 xylanase Michaelis and product complexes: implications for the catalytic mechanism.,Wan Q, Zhang Q, Hamilton-Brehm S, Weiss K, Mustyakimov M, Coates L, Langan P, Graham D, Kovalevsky A Acta Crystallogr D Biol Crystallogr. 2014 Jan;70(Pt 1):11-23. doi:, 10.1107/S1399004713023626. Epub 2013 Dec 24. PMID:24419374[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Torronen A, Mach RL, Messner R, Gonzalez R, Kalkkinen N, Harkki A, Kubicek CP. The two major xylanases from Trichoderma reesei: characterization of both enzymes and genes. Biotechnology (N Y). 1992 Nov;10(11):1461-5. PMID:1369024
- ↑ Jun H, Bing Y, Keying Z, Xuemei D, Daiwen C. Sequencing and expression of the xylanase gene 2 from Trichoderma reesei Rut C-30 and characterization of the recombinant enzyme and its activity on xylan. J Mol Microbiol Biotechnol. 2009;17(3):101-9. doi: 10.1159/000226590. Epub 2009, Jun 26. PMID:19556747 doi:http://dx.doi.org/10.1159/000226590
- ↑ Biely P, Kremnicky L, Alfoldi J, Tenkanen M. Stereochemistry of the hydrolysis of glycosidic linkage by endo-beta-1,4-xylanases of Trichoderma reesei. FEBS Lett. 1994 Dec 12;356(1):137-40. PMID:7988708
- ↑ Torronen A, Mach RL, Messner R, Gonzalez R, Kalkkinen N, Harkki A, Kubicek CP. The two major xylanases from Trichoderma reesei: characterization of both enzymes and genes. Biotechnology (N Y). 1992 Nov;10(11):1461-5. PMID:1369024
- ↑ Wan Q, Zhang Q, Hamilton-Brehm S, Weiss K, Mustyakimov M, Coates L, Langan P, Graham D, Kovalevsky A. X-ray crystallographic studies of family 11 xylanase Michaelis and product complexes: implications for the catalytic mechanism. Acta Crystallogr D Biol Crystallogr. 2014 Jan;70(Pt 1):11-23. doi:, 10.1107/S1399004713023626. Epub 2013 Dec 24. PMID:24419374 doi:http://dx.doi.org/10.1107/S1399004713023626
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