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==crystal structure of a mutant W92A in ketosteroid isomerase (KSI) from Pseudomonas putida biotype B== | |||
<StructureSection load='1w6y' size='340' side='right'caption='[[1w6y]], [[Resolution|resolution]] 2.10Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1w6y]] is a 1 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=1W6Y OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1W6Y FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=EQU:EQUILENIN'>EQU</scene></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=1w6y FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1w6y OCA], [https://pdbe.org/1w6y PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1w6y RCSB], [https://www.ebi.ac.uk/pdbsum/1w6y PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1w6y ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/SDIS_PSEPU SDIS_PSEPU] | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/w6/1w6y_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1w6y ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
A structural motif called the small exterior hydrophobic cluster (SEHC) has been proposed to explain the stabilizing effect mediated by solvent-exposed hydrophobic residues; however, little is known about its biological roles. Unusually, in Delta(5)-3-ketosteroid isomerase from Pseudomonas putida biotype B (KSI-PI) Trp92 is exposed to solvent on the protein surface, forming a SEHC with the side-chains of Leu125 and Val127. In order to identify the role of the SEHC in KSI-PI, mutants of those amino acids associated with the SEHC were prepared. The W92A, L125A/V127A, and W92A/L125A/V127A mutations largely decreased the conformational stability, while the L125F/V127F mutation slightly increased the stability, indicating that hydrophobic packing by the SEHC is important in maintaining stability. The crystal structure of W92A revealed that the decreased stability caused by the removal of the bulky side-chain of Trp92 could be attributed to the destabilization of the surface hydrophobic layer consisting of a solvent-exposed beta-sheet. Consistent with the structural data, the binding affinities for three different steroids showed that the surface hydrophobic layer stabilized by SEHC is required for KSI-PI to efficiently recognize hydrophobic steroids. Unfolding kinetics based on analysis of the Phi(U) value also indicated that the SEHC in the native state was resistant to the unfolding process, despite its solvent-exposed site. Taken together, our results demonstrate that the SEHC plays a key role in the structural integrity that is needed for KSI-PI to stabilize the hydrophobic surface conformation and thereby contributes both to the overall conformational stability and to the binding of hydrophobic steroids in water solution. | |||
Small exterior hydrophobic cluster contributes to conformational stability and steroid binding in ketosteroid isomerase from Pseudomonas putida biotype B.,Yun YS, Nam GH, Kim YG, Oh BH, Choi KY FEBS J. 2005 Apr;272(8):1999-2011. PMID:15819891<ref>PMID:15819891</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1w6y" style="background-color:#fffaf0;"></div> | |||
== | ==See Also== | ||
*[[Ketosteroid Isomerase|Ketosteroid Isomerase]] | |||
== References == | |||
== | <references/> | ||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Pseudomonas putida]] | [[Category: Pseudomonas putida]] | ||
[[Category: Choi KY]] | |||
[[Category: Kim Y-G]] | |||
[[Category: Choi | [[Category: Nam GH]] | ||
[[Category: Kim | [[Category: Oh B-H]] | ||
[[Category: Nam | [[Category: Yun YS]] | ||
[[Category: Oh | |||
[[Category: Yun | |||
Latest revision as of 16:18, 13 December 2023
crystal structure of a mutant W92A in ketosteroid isomerase (KSI) from Pseudomonas putida biotype Bcrystal structure of a mutant W92A in ketosteroid isomerase (KSI) from Pseudomonas putida biotype B
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA structural motif called the small exterior hydrophobic cluster (SEHC) has been proposed to explain the stabilizing effect mediated by solvent-exposed hydrophobic residues; however, little is known about its biological roles. Unusually, in Delta(5)-3-ketosteroid isomerase from Pseudomonas putida biotype B (KSI-PI) Trp92 is exposed to solvent on the protein surface, forming a SEHC with the side-chains of Leu125 and Val127. In order to identify the role of the SEHC in KSI-PI, mutants of those amino acids associated with the SEHC were prepared. The W92A, L125A/V127A, and W92A/L125A/V127A mutations largely decreased the conformational stability, while the L125F/V127F mutation slightly increased the stability, indicating that hydrophobic packing by the SEHC is important in maintaining stability. The crystal structure of W92A revealed that the decreased stability caused by the removal of the bulky side-chain of Trp92 could be attributed to the destabilization of the surface hydrophobic layer consisting of a solvent-exposed beta-sheet. Consistent with the structural data, the binding affinities for three different steroids showed that the surface hydrophobic layer stabilized by SEHC is required for KSI-PI to efficiently recognize hydrophobic steroids. Unfolding kinetics based on analysis of the Phi(U) value also indicated that the SEHC in the native state was resistant to the unfolding process, despite its solvent-exposed site. Taken together, our results demonstrate that the SEHC plays a key role in the structural integrity that is needed for KSI-PI to stabilize the hydrophobic surface conformation and thereby contributes both to the overall conformational stability and to the binding of hydrophobic steroids in water solution. Small exterior hydrophobic cluster contributes to conformational stability and steroid binding in ketosteroid isomerase from Pseudomonas putida biotype B.,Yun YS, Nam GH, Kim YG, Oh BH, Choi KY FEBS J. 2005 Apr;272(8):1999-2011. PMID:15819891[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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