View source for 6pgt


==Protein Tyrosine Phosphatase 1B (1-301), T177A mutant, vanadate bound state==
<StructureSection load='6pgt' size='340' side='right'caption='[[6pgt]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6pgt]] 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=6PGT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6PGT 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=VO4:VANADATE+ION'>VO4</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=6pgt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6pgt OCA], [https://pdbe.org/6pgt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6pgt RCSB], [https://www.ebi.ac.uk/pdbsum/6pgt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6pgt 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 ==
Active-site loops are integral to the function of numerous enzymes. They enable substrate and product binding and release, sequester reaction intermediates, and recruit catalytic groups. Here, we examine the catalytic loop in the enzyme protein tyrosine phosphatase 1B (PTP1B). PTP1B has a mobile so-called WPD loop (named for its three N-terminal residues) that initiates the dephosphorylation of phosphor-tyrosine substrates upon loop closure. We have combined X-ray crystallography, solution NMR, and pre-steady-state kinetics experiments on wild-type and five WPD loop mutants to identify the relationships between the loop structure, dynamics, and function. The motions of the WPD loop are modulated by the formation of weak molecular interactions, where perturbations of these interactions modulate the conformational equilibrium landscape. The point mutants in the WPD loop alter the loop equilibrium position from a predominantly open state (P185A) to 50:50 (F182A), 35:65 (P188A), and predominantly closed states (T177A and P188A). Surprisingly, there is no correlation between the observed catalytic rates in the loop mutants and changes to the WPD loop equilibrium position. Rather, we observe a strong correlation between the rate of dephosphorylation of the phosphocysteine enzyme intermediate and uniform millisecond motions, not only within the loop but also in the adjacent alpha-helical domain of PTP1B. Thus, the control of loop motion and thereby catalytic activity is dispersed and resides within not only the loop sequence but also the surrounding protein architecture. This has broad implications for the general mechanistic understanding of enzyme reactions and the role that flexible loops play in the catalytic cycle.

Uncovering the Molecular Interactions in the Catalytic Loop That Modulate the Conformational Dynamics in Protein Tyrosine Phosphatase 1B.,Cui DS, Lipchock JM, Brookner D, Loria JP J Am Chem Soc. 2019 Aug 5. doi: 10.1021/jacs.9b04470. PMID:31339043<ref>PMID:31339043</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6pgt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Tyrosine phosphatase 3D structures|Tyrosine phosphatase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cui DS]]
[[Category: Lipchock JM]]
[[Category: Loria JP]]