View source for 4gss


==HUMAN GLUTATHIONE S-TRANSFERASE P1-1 Y108F MUTANT==
<StructureSection load='4gss' size='340' side='right'caption='[[4gss]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4gss]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4GSS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4GSS 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]] 2.5&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GTX:S-HEXYLGLUTATHIONE'>GTX</scene>, <scene name='pdbligand=MES:2-(N-MORPHOLINO)-ETHANESULFONIC+ACID'>MES</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=4gss FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4gss OCA], [https://pdbe.org/4gss PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4gss RCSB], [https://www.ebi.ac.uk/pdbsum/4gss PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4gss ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GSTP1_HUMAN GSTP1_HUMAN] Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. Regulates negatively CDK5 activity via p25/p35 translocation to prevent neurodegeneration.<ref>PMID:21668448</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
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    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
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</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=4gss ConSurf].
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== Publication Abstract from PubMed ==
The possible role of the hydroxyl group of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1 has been investigated by means of site-directed mutagenesis, steady-state kinetic analysis, and crystallographic studies. Three representative cosubstrates have been used, i.e. ethacrynic acid, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole, and 1-chloro-2,4-dinitrobenzene. In the presence of ethacrynic acid, the enzyme follows a rapid equilibrium random bi-bi mechanism with a rate-limiting step which occurs after the addition of the substrates and before the release of products. The replacement of Tyr 108 with Phe yields a 14-fold decrease of k(cat), while it does not change appreciably the affinity of the H site for the substrate. In this case, it would appear that the role of the hydroxyl function is to stabilize the transition state for the chemical step, i.e. the Michael addition of GSH to the electrophilic substrate. Crystallographic data are compatible with this conclusion showing the hydroxyl group of Y108 in hydrogen bonding distance of the ketone moiety of ethacrynic acid [Oakley, A. J., Rossjohn, J., Lo Bello, M., Caccuri, A. M., Federici, G., &amp; Parker, M. W. (1997) Biochemistry 36, 576-585]. Moreover, no structural differences are observed between the Y108F mutant and the wild type, suggesting that the removal of the hydroxyl group is solely responsible for the loss of activity. A different involvement of Tyr 108 appears in the catalyzed conjugation of 7-chloro-4-nitrobenz-2-oxa-1,3-diazole with GSH in which the rate-limiting step is of a physical nature, probably a structural transition of the ternary complex. The substitution of Tyr 108 yields an approximately 7-fold increase of k(cat) and a constant k(cat)/Km(NBD-Cl) value. Lack of a critical hydrogen bond between 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and Tyr 108 appears to be the basis of the increased k(cat). In the 1-chloro-2,4-dinitrobenzene/GSH system, no appreciable changes of kinetics parameters are found in the Y108F mutant. We conclude that Y108 has a multifunctional role in glutathione transferase P1-1 catalysis, depending on the nature of the electrophilic cosubstrate.

Multifunctional role of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1. Crystallographic and kinetic studies on the Y108F mutant enzyme.,Lo Bello M, Oakley AJ, Battistoni A, Mazzetti AP, Nuccetelli M, Mazzarese G, Rossjohn J, Parker MW, Ricci G Biochemistry. 1997 May 20;36(20):6207-17. PMID:9166793<ref>PMID:9166793</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Glutathione S-transferase 3D structures|Glutathione S-transferase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Oakley A]]
[[Category: Parker M]]
[[Category: Rossjohn J]]