7l0c: Difference between revisions
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==Ligand-free PTP1B T177G== | |||
<StructureSection load='7l0c' size='340' side='right'caption='[[7l0c]], [[Resolution|resolution]] 1.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[7l0c]] 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=7L0C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7L0C 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]] 1.8Å</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=7l0c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7l0c OCA], [https://pdbe.org/7l0c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7l0c RCSB], [https://www.ebi.ac.uk/pdbsum/7l0c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7l0c 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> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Catalysis by protein tyrosine phosphatases (PTPs) relies on the motion of a flexible protein loop (the WPD-loop) that carries a residue acting as a general acid/base catalyst during the PTP-catalyzed reaction. The orthogonal substitutions of a noncatalytic residue in the WPD-loops of YopH and PTP1B result in shifted pH-rate profiles from an altered kinetic pK a of the nucleophilic cysteine. Compared to wild type, the G352T YopH variant has a broadened pH-rate profile, similar activity at optimal pH, but significantly higher activity at low pH. Changes in the corresponding PTP1B T177G variant are more modest and in the opposite direction, with a narrowed pH profile and less activity in the most acidic range. Crystal structures of the variants show no structural perturbations but suggest an increased preference for the WPD-loop-closed conformation. Computational analysis confirms a shift in loop conformational equilibrium in favor of the closed conformation, arising from a combination of increased stability of the closed state and destabilization of the loop-open state. Simulations identify the origins of this population shift, revealing differences in the flexibility of the WPD-loop and neighboring regions. Our results demonstrate that changes to the pH dependency of catalysis by PTPs can result from small changes in amino acid composition in their WPD-loops affecting only loop dynamics and conformational equilibrium. The perturbation of kinetic pK a values of catalytic residues by nonchemical processes affords a means for nature to alter an enzyme's pH dependency by a less disruptive path than altering electrostatic networks around catalytic residues themselves. | |||
Single Residue on the WPD-Loop Affects the pH Dependency of Catalysis in Protein Tyrosine Phosphatases.,Shen R, Crean RM, Johnson SJ, Kamerlin SCL, Hengge AC JACS Au. 2021 May 24;1(5):646-659. doi: 10.1021/jacsau.1c00054. Epub 2021 Apr 23. PMID:34308419<ref>PMID:34308419</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 7l0c" style="background-color:#fffaf0;"></div> | ||
[[Category: Johnson | |||
[[Category: | ==See Also== | ||
*[[Tyrosine phosphatase 3D structures|Tyrosine phosphatase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | |||
[[Category: Large Structures]] | |||
[[Category: Hengge AC]] | |||
[[Category: Johnson SJ]] | |||
[[Category: Shen RD]] | |||
Latest revision as of 18:35, 18 October 2023
Ligand-free PTP1B T177GLigand-free PTP1B T177G
Structural highlights
FunctionPTN1_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.[1] [2] Publication Abstract from PubMedCatalysis by protein tyrosine phosphatases (PTPs) relies on the motion of a flexible protein loop (the WPD-loop) that carries a residue acting as a general acid/base catalyst during the PTP-catalyzed reaction. The orthogonal substitutions of a noncatalytic residue in the WPD-loops of YopH and PTP1B result in shifted pH-rate profiles from an altered kinetic pK a of the nucleophilic cysteine. Compared to wild type, the G352T YopH variant has a broadened pH-rate profile, similar activity at optimal pH, but significantly higher activity at low pH. Changes in the corresponding PTP1B T177G variant are more modest and in the opposite direction, with a narrowed pH profile and less activity in the most acidic range. Crystal structures of the variants show no structural perturbations but suggest an increased preference for the WPD-loop-closed conformation. Computational analysis confirms a shift in loop conformational equilibrium in favor of the closed conformation, arising from a combination of increased stability of the closed state and destabilization of the loop-open state. Simulations identify the origins of this population shift, revealing differences in the flexibility of the WPD-loop and neighboring regions. Our results demonstrate that changes to the pH dependency of catalysis by PTPs can result from small changes in amino acid composition in their WPD-loops affecting only loop dynamics and conformational equilibrium. The perturbation of kinetic pK a values of catalytic residues by nonchemical processes affords a means for nature to alter an enzyme's pH dependency by a less disruptive path than altering electrostatic networks around catalytic residues themselves. Single Residue on the WPD-Loop Affects the pH Dependency of Catalysis in Protein Tyrosine Phosphatases.,Shen R, Crean RM, Johnson SJ, Kamerlin SCL, Hengge AC JACS Au. 2021 May 24;1(5):646-659. doi: 10.1021/jacsau.1c00054. Epub 2021 Apr 23. PMID:34308419[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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