2a96: Difference between revisions
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< | ==Crystal structure of phosphate tethered PhoN of S. typhimurium== | ||
<StructureSection load='2a96' size='340' side='right'caption='[[2a96]], [[Resolution|resolution]] 2.50Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2a96]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Salmonella_enterica_subsp._enterica_serovar_Typhimurium Salmonella enterica subsp. enterica serovar Typhimurium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2A96 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2A96 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]] 2.5Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</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=2a96 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2a96 OCA], [https://pdbe.org/2a96 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2a96 RCSB], [https://www.ebi.ac.uk/pdbsum/2a96 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2a96 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q8KRU6_SALTM Q8KRU6_SALTM] | |||
== 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/a9/2a96_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2a96 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The Salmonella typhimurium PhoN protein is a nonspecific acid phosphatase and belongs to the phosphatidic acid phosphatase type 2 (PAP2) superfamily. We report here the crystal structures of phosphate-bound PhoN, the PhoN-tungstate complex, and the T159D mutant of PhoN along with functional characterization of three mutants: L39T, T159D, and D201N. Invariant active site residues, Lys-123, Arg-130, Ser-156, Gly-157, His-158, and Arg-191, interact with phosphate and tungstate oxyanions. Ser-156 also accepts a hydrogen bond from Thr-159. The T159D mutation, surprisingly, severely diminishes phosphatase activity, apparently by disturbing the active site scaffold: Arg-191 is swung out of the active site resulting in conformational changes in His-158 and His-197 residues. Our results reveal a hitherto unknown functional role of Arg-191, namely, restricting the active conformation of catalytic His-158 and His-197 residues. Consistent with the conserved nature of Asp-201 in the PAP2 superfamily, the D201N mutation completely abolished phosphatase activity. On the basis of this observation and in silico analysis we suggest that the crucial mechanistic role of Asp-201 is to stabilize the positive charge on the phosphohistidine intermediate generated by the transfer of phosphoryl to the nucleophile, His-197, located within hydrogen bond distance to the invariant Asp-201. This is in contrast to earlier suggestions that Asp-201 stabilizes His-197 and the His197-Asp201 dyad facilitates formation of the phosphoenzyme intermediate through a charge-relay system. Finally, the L39T mutation in the conserved polyproline motif (39LPPPP43) of dimeric PhoN leads to a marginal reduction in activity, in contrast to the nearly 50-fold reduction observed for monomeric Prevotella intermedia acid phosphatase, suggesting that the varying quaternary structure of PhoN orthologues may have functional significance. | |||
Structure and mutational analysis of the PhoN protein of Salmonella typhimurium provide insight into mechanistic details.,Makde RD, Mahajan SK, Kumar V Biochemistry. 2007 Feb 27;46(8):2079-90. Epub 2007 Jan 31. PMID:17263560<ref>PMID:17263560</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 2a96" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Acid phosphatase 3D structures|Acid phosphatase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
[[Category: Salmonella enterica subsp. enterica serovar Typhimurium]] | |||
[[Category: Kumar V]] | |||
== | [[Category: Mahajan SK]] | ||
< | [[Category: Makde RD]] | ||
[[Category: | |||
[[Category: Salmonella | |||
[[Category: Kumar | |||
[[Category: Mahajan | |||
[[Category: Makde | |||
Latest revision as of 11:59, 6 November 2024
Crystal structure of phosphate tethered PhoN of S. typhimuriumCrystal structure of phosphate tethered PhoN of S. typhimurium
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 PubMedThe Salmonella typhimurium PhoN protein is a nonspecific acid phosphatase and belongs to the phosphatidic acid phosphatase type 2 (PAP2) superfamily. We report here the crystal structures of phosphate-bound PhoN, the PhoN-tungstate complex, and the T159D mutant of PhoN along with functional characterization of three mutants: L39T, T159D, and D201N. Invariant active site residues, Lys-123, Arg-130, Ser-156, Gly-157, His-158, and Arg-191, interact with phosphate and tungstate oxyanions. Ser-156 also accepts a hydrogen bond from Thr-159. The T159D mutation, surprisingly, severely diminishes phosphatase activity, apparently by disturbing the active site scaffold: Arg-191 is swung out of the active site resulting in conformational changes in His-158 and His-197 residues. Our results reveal a hitherto unknown functional role of Arg-191, namely, restricting the active conformation of catalytic His-158 and His-197 residues. Consistent with the conserved nature of Asp-201 in the PAP2 superfamily, the D201N mutation completely abolished phosphatase activity. On the basis of this observation and in silico analysis we suggest that the crucial mechanistic role of Asp-201 is to stabilize the positive charge on the phosphohistidine intermediate generated by the transfer of phosphoryl to the nucleophile, His-197, located within hydrogen bond distance to the invariant Asp-201. This is in contrast to earlier suggestions that Asp-201 stabilizes His-197 and the His197-Asp201 dyad facilitates formation of the phosphoenzyme intermediate through a charge-relay system. Finally, the L39T mutation in the conserved polyproline motif (39LPPPP43) of dimeric PhoN leads to a marginal reduction in activity, in contrast to the nearly 50-fold reduction observed for monomeric Prevotella intermedia acid phosphatase, suggesting that the varying quaternary structure of PhoN orthologues may have functional significance. Structure and mutational analysis of the PhoN protein of Salmonella typhimurium provide insight into mechanistic details.,Makde RD, Mahajan SK, Kumar V Biochemistry. 2007 Feb 27;46(8):2079-90. Epub 2007 Jan 31. PMID:17263560[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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