1w6y
From Proteopedia
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| - | [[Image:1w6y.gif|left|200px]]<br /> | + | [[Image:1w6y.gif|left|200px]]<br /><applet load="1w6y" size="450" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1w6y" size="450" color="white" frame="true" align="right" spinBox="true" | + | |
caption="1w6y, resolution 2.1Å" /> | caption="1w6y, resolution 2.1Å" /> | ||
'''CRYSTAL STRUCTURE OF A MUTANT W92A IN KETOSTEROID ISOMERASE (KSI) FROM PSEUDOMONAS PUTIDA BIOTYPE B'''<br /> | '''CRYSTAL STRUCTURE OF A MUTANT W92A IN KETOSTEROID ISOMERASE (KSI) FROM PSEUDOMONAS PUTIDA BIOTYPE B'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1W6Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida] with EQU and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] | + | 1W6Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pseudomonas_putida Pseudomonas putida] with EQU and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [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] Known structural/functional Site: <scene name='pdbsite=AC1:Bme Binding Site For Chain A'>AC1</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1W6Y OCA]. |
==Reference== | ==Reference== | ||
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[[Category: solvent-exposed]] | [[Category: solvent-exposed]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 18:32:53 2007'' |
Revision as of 16:23, 18 December 2007
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CRYSTAL STRUCTURE OF A MUTANT W92A IN KETOSTEROID ISOMERASE (KSI) FROM PSEUDOMONAS PUTIDA BIOTYPE B
Overview
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.
About this Structure
1W6Y is a Single protein structure of sequence from Pseudomonas putida with EQU and BME as ligands. Active as Steroid Delta-isomerase, with EC number 5.3.3.1 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
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
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