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| | ==Xylose Isomerase in Substrate and Inhibitor Michaelis States: Atomic Resolution Studies of a Metal-Mediated Hydride Shift== | | ==Xylose Isomerase in Substrate and Inhibitor Michaelis States: Atomic Resolution Studies of a Metal-Mediated Hydride Shift== |
| - | <StructureSection load='1s5m' size='340' side='right' caption='[[1s5m]], [[Resolution|resolution]] 0.98Å' scene=''> | + | <StructureSection load='1s5m' size='340' side='right'caption='[[1s5m]], [[Resolution|resolution]] 0.98Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1s5m]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"actinomyces_olivochromogenus"_(sic)_waksman_1923 "actinomyces olivochromogenus" (sic) waksman 1923]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S5M OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1S5M FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1s5m]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_olivochromogenes Streptomyces olivochromogenes]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1S5M OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1S5M FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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]] 0.98Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">XYLA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1963 "Actinomyces olivochromogenus" (sic) Waksman 1923])</td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Xylose_isomerase Xylose isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.5 5.3.1.5] </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=1s5m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s5m OCA], [https://pdbe.org/1s5m PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1s5m RCSB], [https://www.ebi.ac.uk/pdbsum/1s5m PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1s5m 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=1s5m FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1s5m OCA], [http://pdbe.org/1s5m PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1s5m RCSB], [http://www.ebi.ac.uk/pdbsum/1s5m PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1s5m ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/XYLA_STROL XYLA_STROL]] Involved in D-xylose catabolism. | + | [https://www.uniprot.org/uniprot/XYLA_STROL XYLA_STROL] Involved in D-xylose catabolism. |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | </div> | | </div> |
| | <div class="pdbe-citations 1s5m" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 1s5m" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[D-xylose isomerase 3D structures|D-xylose isomerase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Xylose isomerase]] | + | [[Category: Large Structures]] |
| - | [[Category: Fenn, T D]] | + | [[Category: Streptomyces olivochromogenes]] |
| - | [[Category: Petsko, G A]] | + | [[Category: Fenn TD]] |
| - | [[Category: Ringe, D]] | + | [[Category: Petsko GA]] |
| - | [[Category: Atomic resolution]] | + | [[Category: Ringe D]] |
| - | [[Category: Hydride shift]]
| + | |
| - | [[Category: Isomerase]]
| + | |
| - | [[Category: Tim barrel]]
| + | |
| Structural highlights
Function
XYLA_STROL Involved in D-xylose catabolism.
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
Xylose isomerase (E.C. 5.3.1.5) catalyzes the interconversion of aldose and ketose sugars and has an absolute requirement for two divalent cations at its active site to drive the hydride transfer rates of sugar isomerization. Evidence suggests some degree of metal movement at the second metal site, although how this movement may affect catalysis is unknown. The 0.95 A resolution structure of the xylitol-inhibited enzyme presented here suggests three alternative positions for the second metal ion, only one of which appears positioned in a catalytically competent manner. To complete the reaction, an active site hydroxyl species appears appropriately positioned for hydrogen transfer, as evidenced by precise bonding distances. Conversely, the 0.98 A resolution structure of the enzyme with glucose bound in the alpha-pyranose state only shows one of the metal ion conformations at the second metal ion binding site, suggesting that the linear form of the sugar is required to promote the second and third metal ion conformations. The two structures suggest a strong degree of conformational flexibility at the active site, which seems required for catalysis and may explain the poor rate of turnover for this enzyme. Further, the pyranose structure implies that His53 may act as the initial acid responsible for ring opening of the sugar to the aldose form, an observation that has been difficult to establish in previous studies. The glucose ring also appears to display significant segmented disorder in a manner suggestive of ring opening, perhaps lending insight into means of enzyme destabilization of the ground state to promote catalysis. On the basis of these results, we propose a modified version of the bridged bimetallic mechanism for hydride transfer in the case of Streptomyces olivochromogenes xylose isomerase.
Xylose isomerase in substrate and inhibitor michaelis states: atomic resolution studies of a metal-mediated hydride shift.,Fenn TD, Ringe D, Petsko GA Biochemistry. 2004 Jun 1;43(21):6464-74. PMID:15157080[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Fenn TD, Ringe D, Petsko GA. Xylose isomerase in substrate and inhibitor michaelis states: atomic resolution studies of a metal-mediated hydride shift. Biochemistry. 2004 Jun 1;43(21):6464-74. PMID:15157080 doi:10.1021/bi049812o
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