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| | ==Crystal structure of ketosteroid isomerase Y14AY55FD99A from Pseudomonas testosteroni== | | ==Crystal structure of ketosteroid isomerase Y14AY55FD99A from Pseudomonas testosteroni== |
| - | <StructureSection load='3t8u' size='340' side='right' caption='[[3t8u]], [[Resolution|resolution]] 2.50Å' scene=''> | + | <StructureSection load='3t8u' size='340' side='right'caption='[[3t8u]], [[Resolution|resolution]] 2.50Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3t8u]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_11996 Atcc 11996]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3T8U OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3T8U FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3t8u]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Comamonas_testosteroni Comamonas testosteroni]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3T8U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3T8U FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</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]] 2.5Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3rgr|3rgr]], [[3t8n|3t8n]], [[3m8c|3m8c]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ksi ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=285 ATCC 11996])</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=3t8u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3t8u OCA], [https://pdbe.org/3t8u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3t8u RCSB], [https://www.ebi.ac.uk/pdbsum/3t8u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3t8u 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/Steroid_Delta-isomerase Steroid Delta-isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.3.1 5.3.3.1] </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=3t8u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3t8u OCA], [http://pdbe.org/3t8u PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3t8u RCSB], [http://www.ebi.ac.uk/pdbsum/3t8u PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3t8u ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| - | <div style="background-color:#fffaf0;">
| + | == Function == |
| - | == Publication Abstract from PubMed == | + | [https://www.uniprot.org/uniprot/SDIS_COMTE SDIS_COMTE] |
| - | Prior site-directed mutagenesis studies in bacterial ketosteroid isomerase (KSI) reported that substitution of both oxyanion hole hydrogen bond donors give a 10^5-10^8 fold rate reduction suggesting that the oxyanion hole may provide the major contribution to KSI catalysis. But these seemingly conservative mutations replaced the oxyanion hole hydrogen bond donors with hydrophobic side chains that could lead to suboptimal solvation of the incipient oxyanion in the mutants, thereby potentially exaggerating the apparent energetic benefit of the hydrogen bonds relative to water-mediated hydrogen bonds in solution. We determined the functional and structural consequences of substituting the oxyanion hole hydrogen bond donors and several residues surrounding the oxyanion hole with smaller residues in an attempt to create a local site that would provide interactions more analogous to those in aqueous solution. These more drastic mutations created an active site cavity estimated to be ~650 A^3 and sufficient for occupancy by 15-17 water molecules and led to a rate decrease of only ~10^3-fold for KSI from two different species, a much smaller effect than that observed from more traditional conservative mutations. The results underscore the strong context dependence of hydrogen bond energetics and suggest that the oxyanion hole provides an important, but moderate, catalytic contribution relative to the interactions in the corresponding solution reaction.
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| - | Evaluating the Catalytic Contribution from the Oxyanion Hole in Ketosteroid Isomerase.,Schwans JP, Sunden F, Gonzalez A, Tsai Y, Herschlag D J Am Chem Soc. 2011 Nov 4. PMID:22053826<ref>PMID:22053826</ref>
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| - | | + | |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| - | </div>
| + | |
| - | <div class="pdbe-citations 3t8u" style="background-color:#fffaf0;"></div>
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| | ==See Also== | | ==See Also== |
| | *[[Ketosteroid Isomerase|Ketosteroid Isomerase]] | | *[[Ketosteroid Isomerase|Ketosteroid Isomerase]] |
| - | == References == | |
| - | <references/> | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Atcc 11996]] | + | [[Category: Comamonas testosteroni]] |
| - | [[Category: Steroid Delta-isomerase]] | + | [[Category: Large Structures]] |
| - | [[Category: Gonzalez, A]] | + | [[Category: Gonzalez A]] |
| - | [[Category: Herschlag, D]] | + | [[Category: Herschlag D]] |
| - | [[Category: Schwans, J]] | + | [[Category: Schwans J]] |
| - | [[Category: Sunden, F]] | + | [[Category: Sunden F]] |
| - | [[Category: Tsai, Y]] | + | [[Category: Tsai Y]] |
| - | [[Category: Isomerase]]
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