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| | ==Structure Of A Cold-Adapted Family 8 Xylanase== | | ==Structure Of A Cold-Adapted Family 8 Xylanase== |
| - | <StructureSection load='2a8z' size='340' side='right' caption='[[2a8z]], [[Resolution|resolution]] 3.20Å' scene=''> | + | <StructureSection load='2a8z' size='340' side='right'caption='[[2a8z]], [[Resolution|resolution]] 3.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2a8z]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"alteromonas_marinopraesens"_(zobell_and_upham_1944)_baumann_et_al._1972 "alteromonas marinopraesens" (zobell and upham 1944) baumann et al. 1972]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A8Z OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2A8Z FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2a8z]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudoalteromonas_haloplanktis Pseudoalteromonas haloplanktis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A8Z OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2A8Z FirstGlance]. <br> |
| - | </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1h12|1h12]], [[1h13|1h13]], [[1h14|1h14]], [[1xw2|1xw2]], [[1xwq|1xwq]], [[1xwt|1xwt]]</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]] 3.2Å</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'>[https://proteopedia.org/fgij/fg.htm?mol=2a8z FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a8z OCA], [https://pdbe.org/2a8z PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2a8z RCSB], [https://www.ebi.ac.uk/pdbsum/2a8z PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2a8z ProSAT]</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=2a8z FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a8z OCA], [http://pdbe.org/2a8z PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2a8z RCSB], [http://www.ebi.ac.uk/pdbsum/2a8z PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2a8z ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/Q8RJN8_PSEHA Q8RJN8_PSEHA] |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Endo-1,4-beta-xylanase]] | + | [[Category: Large Structures]] |
| - | [[Category: Beeumen, J Van]] | + | [[Category: Pseudoalteromonas haloplanktis]] |
| - | [[Category: Collins, T]] | + | [[Category: Collins T]] |
| - | [[Category: Feller, G]] | + | [[Category: De Vos D]] |
| - | [[Category: Gerday, C]]
| + | [[Category: Feller G]] |
| - | [[Category: Hoyoux, A]]
| + | [[Category: Gerday C]] |
| - | [[Category: Savvides, S N]]
| + | [[Category: Hoyoux A]] |
| - | [[Category: Vos, D De]]
| + | [[Category: Savvides SN]] |
| - | [[Category: Cold adaptation]] | + | [[Category: Van Beeumen J]] |
| - | [[Category: Family 8]] | + | |
| - | [[Category: Glycosyl hydrolase]] | + | |
| - | [[Category: Hydrolase]] | + | |
| - | [[Category: Psychrophilic]] | + | |
| - | [[Category: Temperature]]
| + | |
| - | [[Category: Xylan degradation]]
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| Structural highlights
Function
Q8RJN8_PSEHA
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
Site-directed mutagenesis and a comparative characterisation of the kinetic parameters, pH dependency of activity and thermal stability of mutant and wild-type enzymes have been used in association with crystallographic analysis to delineate the functions of several active site residues in a novel glycoside hydrolase family 8 xylanase. Each of the residues investigated plays an essential role in this enzyme: E78 as the general acid, D281 as the general base and in orientating the nucleophilic water molecule, Y203 in maintaining the position of the nucleophilic water molecule and in structural integrity and D144 in sugar ring distortion and transition state stabilization. Interestingly, although crystal structure analyses and the pH-activity profiles clearly identify the functions of E78 and D281, substitution of these residues with their amide derivatives results in only a 250-fold and 700-fold reduction in their apparent k(cat) values, respectively. This, in addition to the observation that the proposed general base is not conserved in all glycoside hydrolase family 8 enzymes, indicates that the mechanistic architecture in this family of inverting enzymes is more complex than is conventionally believed and points to a diversity in the identity of the mechanistically important residues as well as in the arrangement of the intricate microenvironment of the active site among members of this family.
Study of the active site residues of a glycoside hydrolase family 8 xylanase.,Collins T, De Vos D, Hoyoux A, Savvides SN, Gerday C, Van Beeumen J, Feller G J Mol Biol. 2005 Nov 25;354(2):425-35. Epub 2005 Oct 10. PMID:16246370[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Collins T, De Vos D, Hoyoux A, Savvides SN, Gerday C, Van Beeumen J, Feller G. Study of the active site residues of a glycoside hydrolase family 8 xylanase. J Mol Biol. 2005 Nov 25;354(2):425-35. Epub 2005 Oct 10. PMID:16246370 doi:10.1016/j.jmb.2005.09.064
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