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| | ==Crystal structure of KSI Y57S mutant== | | ==Crystal structure of KSI Y57S mutant== |
| - | <StructureSection load='1k41' size='340' side='right' caption='[[1k41]], [[Resolution|resolution]] 2.20Å' scene=''> | + | <StructureSection load='1k41' size='340' side='right'caption='[[1k41]], [[Resolution|resolution]] 2.20Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1k41]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_fluorescens_putidus"_flugge_1886 "bacillus fluorescens putidus" flugge 1886]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K41 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1K41 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1k41]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K41 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1K41 FirstGlance]. <br> |
| - | </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> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.2Å</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=1k41 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k41 OCA], [http://pdbe.org/1k41 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1k41 RCSB], [http://www.ebi.ac.uk/pdbsum/1k41 PDBsum]</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=1k41 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k41 OCA], [https://pdbe.org/1k41 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1k41 RCSB], [https://www.ebi.ac.uk/pdbsum/1k41 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1k41 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/SDIS_PSEPU SDIS_PSEPU] |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k4/1k41_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/k4/1k41_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Bacillus fluorescens putidus flugge 1886]] | + | [[Category: Large Structures]] |
| - | [[Category: Steroid Delta-isomerase]] | + | [[Category: Pseudomonas putida]] |
| - | [[Category: Cha, S S]] | + | [[Category: Cha SS]] |
| - | [[Category: Choi, K Y]] | + | [[Category: Choi KY]] |
| - | [[Category: Jang, D S]] | + | [[Category: Jang DS]] |
| - | [[Category: Lee, T H]] | + | [[Category: Lee TH]] |
| - | [[Category: Nam, G H]] | + | [[Category: Nam GH]] |
| - | [[Category: Oh, B H]] | + | [[Category: Oh BH]] |
| - | [[Category: Isomerase]]
| + | |
| - | [[Category: Ksi y57s helix]]
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| Structural highlights
Function
SDIS_PSEPU
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
Ketosteroid isomerase (KSI) from Pseudomonas putida biotype B is a homodimeric enzyme catalyzing an allylic rearrangement of Delta5-3-ketosteroids at rates comparable with the diffusion-controlled limit. The tyrosine triad (Tyr14.Tyr55.Tyr30) forming a hydrogen-bond network in the apolar active site of KSI has been characterized in an effort to identify the roles of the phenyl rings in catalysis, stability, and unfolding of the enzyme. The replacement of Tyr14, a catalytic residue, with serine resulted in a 33-fold decrease of kcat, while the replacements of Tyr30 and Tyr55 with serine decreased kcat by 4- and 51-fold, respectively. The large decrease of kcat for Y55S could be due to the structural perturbation of alpha-helix A3, which results in the reorientation of the active-site residues as judged by the crystal structure of Y55S determined at 2.2 A resolution. Consistent with the analysis of the Y55S crystal structure, the far-UV circular dichroism spectra of Y14S, Y30S, and Y55S indicated that the elimination of the phenyl ring of the tyrosine reduced significantly the content of alpha-helices. Urea-induced equilibrium unfolding experiments revealed that the DeltaG(U)H2O values of Y14S, Y30S, and Y55S were significantly decreased by 11.9, 13.7, and 9.5 kcal/mol, respectively, as compared with that of the wild type. A characterization of the unfolding kinetics based on PhiU-value analysis indicates that the interactions mediated by the tyrosine triad in the native state are very resistant to unfolding. Taken together, our results demonstrate that the internal packing by the phenyl rings in the active-site tyrosine triad contributes to the conformational stability and catalytic activity of KSI by maintaining the structural integrity of the alpha-helices.
Maintenance of alpha-helical structures by phenyl rings in the active-site tyrosine triad contributes to catalysis and stability of ketosteroid isomerase from Pseudomonas putida biotype B.,Nam GH, Jang DS, Cha SS, Lee TH, Kim DH, Hong BH, Yun YS, Oh BH, Choi KY Biochemistry. 2001 Nov 13;40(45):13529-37. PMID:11695900[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Nam GH, Jang DS, Cha SS, Lee TH, Kim DH, Hong BH, Yun YS, Oh BH, Choi KY. Maintenance of alpha-helical structures by phenyl rings in the active-site tyrosine triad contributes to catalysis and stability of ketosteroid isomerase from Pseudomonas putida biotype B. Biochemistry. 2001 Nov 13;40(45):13529-37. PMID:11695900
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