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[[Image:1pa1.jpg|left|200px]]
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{{STRUCTURE_1pa1|  PDB=1pa1  |  SCENE=  }}
'''Crystal structure of the C215D mutant of protein tyrosine phosphatase 1B'''


==Crystal structure of the C215D mutant of protein tyrosine phosphatase 1B==
<StructureSection load='1pa1' size='340' side='right'caption='[[1pa1]], [[Resolution|resolution]] 1.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pa1]] is a 1 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=1PA1 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PA1 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]] 1.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=1pa1 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pa1 OCA], [https://pdbe.org/1pa1 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pa1 RCSB], [https://www.ebi.ac.uk/pdbsum/1pa1 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pa1 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PTN1_HUMAN PTN1_HUMAN] Tyrosine-protein phosphatase which acts as a regulator of endoplasmic reticulum unfolded protein response. Mediates dephosphorylation of EIF2AK3/PERK; inactivating the protein kinase activity of EIF2AK3/PERK. May play an important role in CKII- and p60c-src-induced signal transduction cascades. May regulate the EFNA5-EPHA3 signaling pathway which modulates cell reorganization and cell-cell repulsion.<ref>PMID:21135139</ref> <ref>PMID:22169477</ref>
== 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/pa/1pa1_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=1pa1 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We have characterized the C215D active-site mutant of protein-tyrosine phosphatase-1B (PTP-1B) and solved the crystal structure of the catalytic domain of the apoenzyme to a resolution of 1.6 A. The mutant enzyme displayed maximal catalytic activity at pH approximately 4.5, which is significantly lower than the pH optimum of 6 for wild-type PTP-1B. Although both forms of the enzyme exhibited identical Km values for hydrolysis of p-nitrophenyl phosphate at pH 4.5 and 6, the kcat values of C215D were approximately 70- and approximately 7000-fold lower than those of wild-type PTP-1B, respectively. Arrhenius plots revealed that the mutant and wild-type enzymes displayed activation energies of 61 +/- 1 and 18 +/- 2 kJ/mol, respectively, at their pH optima. Unlike wild-type PTP-1B, C215D-mediated p-nitrophenyl phosphate hydrolysis was inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane, suggesting a direct involvement of Asp215 in catalysis. Increasing solvent microviscosity with sucrose (up to 40% (w/v)) caused a significant decrease in kcat/Km of the wild-type enzyme, but did not alter the catalytic efficiency of the mutant protein. Structurally, the apoenzyme was identical to wild-type PTP-1B, aside from the flexible WPD loop region, which was in both "open" and "closed" conformations. At physiological pH, the C215D mutant of PTP-1B should be an effective substrate-trapping mutant that can be used to identify cellular substrates of PTP-1B. In addition, because of its insensitivity to oxidation, this mutant may be used for screening fermentation broth and other natural products to identify inhibitors of PTP-1B.


==Overview==
Functional characterization and crystal structure of the C215D mutant of protein-tyrosine phosphatase-1B.,Romsicki Y, Scapin G, Beaulieu-Audy V, Patel S, Becker JW, Kennedy BP, Asante-Appiah E J Biol Chem. 2003 Aug 1;278(31):29009-15. Epub 2003 May 13. PMID:12748196<ref>PMID:12748196</ref>
We have characterized the C215D active-site mutant of protein-tyrosine phosphatase-1B (PTP-1B) and solved the crystal structure of the catalytic domain of the apoenzyme to a resolution of 1.6 A. The mutant enzyme displayed maximal catalytic activity at pH approximately 4.5, which is significantly lower than the pH optimum of 6 for wild-type PTP-1B. Although both forms of the enzyme exhibited identical Km values for hydrolysis of p-nitrophenyl phosphate at pH 4.5 and 6, the kcat values of C215D were approximately 70- and approximately 7000-fold lower than those of wild-type PTP-1B, respectively. Arrhenius plots revealed that the mutant and wild-type enzymes displayed activation energies of 61 +/- 1 and 18 +/- 2 kJ/mol, respectively, at their pH optima. Unlike wild-type PTP-1B, C215D-mediated p-nitrophenyl phosphate hydrolysis was inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane, suggesting a direct involvement of Asp215 in catalysis. Increasing solvent microviscosity with sucrose (up to 40% (w/v)) caused a significant decrease in kcat/Km of the wild-type enzyme, but did not alter the catalytic efficiency of the mutant protein. Structurally, the apoenzyme was identical to wild-type PTP-1B, aside from the flexible WPD loop region, which was in both "open" and "closed" conformations. At physiological pH, the C215D mutant of PTP-1B should be an effective substrate-trapping mutant that can be used to identify cellular substrates of PTP-1B. In addition, because of its insensitivity to oxidation, this mutant may be used for screening fermentation broth and other natural products to identify inhibitors of PTP-1B.


==About this Structure==
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
1PA1 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PA1 OCA].
</div>
<div class="pdbe-citations 1pa1" style="background-color:#fffaf0;"></div>


==Reference==
==See Also==
Functional characterization and crystal structure of the C215D mutant of protein-tyrosine phosphatase-1B., Romsicki Y, Scapin G, Beaulieu-Audy V, Patel S, Becker JW, Kennedy BP, Asante-Appiah E, J Biol Chem. 2003 Aug 1;278(31):29009-15. Epub 2003 May 13. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/12748196 12748196]
*[[Tyrosine phosphatase 3D structures|Tyrosine phosphatase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Homo sapiens]]
[[Category: Protein-tyrosine-phosphatase]]
[[Category: Large Structures]]
[[Category: Single protein]]
[[Category: Asante-Appiah E]]
[[Category: Asante-Appiah, E.]]
[[Category: Beaulieu-Audy V]]
[[Category: Beaulieu-Audy, V.]]
[[Category: Becker JW]]
[[Category: Becker, J W.]]
[[Category: Kennedy B]]
[[Category: Kennedy, B.]]
[[Category: Patel SB]]
[[Category: Patel, S B.]]
[[Category: Romsicki Y]]
[[Category: Romsicki, Y.]]
[[Category: Scapin G]]
[[Category: Scapin, G.]]
[[Category: Active-site mutant]]
[[Category: Catalytic loop]]
[[Category: Phosphatase]]
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