View source for 2qf2


==Rat cytosolic PEPCK in complex with oxaloacetic acid and GDP.==
<StructureSection load='2qf2' size='340' side='right'caption='[[2qf2]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2qf2]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QF2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QF2 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]] 1.65&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GDP:GUANOSINE-5-DIPHOSPHATE'>GDP</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=OAA:OXALOACETATE+ION'>OAA</scene>, <scene name='pdbligand=PYR:PYRUVIC+ACID'>PYR</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=2qf2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qf2 OCA], [https://pdbe.org/2qf2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qf2 RCSB], [https://www.ebi.ac.uk/pdbsum/2qf2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qf2 ProSAT]</span></td></tr>
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== Function ==
[https://www.uniprot.org/uniprot/PCKGC_RAT PCKGC_RAT] Catalyzes the conversion of oxaloacetate (OAA) to phosphoenolpyruvate (PEP), the rate-limiting step in the metabolic pathway that produces glucose from lactate and other precursors derived from the citric acid cycle.
== 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/qf/2qf2_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=2qf2 ConSurf].
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== Publication Abstract from PubMed ==
The structures of the rat cytosolic isoform of phosphoenolpyruvate carboxykinase (PEPCK) reported in the PEPCK-Mn2+, -Mn2+-oxaloacetic acid (OAA), -Mn2+-OAA-Mn2+-guanosine-5'-diphosphate (GDP), and -Mn2+-Mn2+-guanosine-5'-tri-phosphate (GTP) complexes provide insight into the mechanism of phosphoryl transfer and decarboxylation mediated by this enzyme. OAA is observed to bind in a number of different orientations coordinating directly to the active site metal. The Mn2+-OAA and Mn2+-OAA-Mn2+GDP structures illustrate inner-sphere coordination of OAA to the manganese ion through the displacement of two of the three water molecules coordinated to the metal in the holo-enzyme by the C3 and C4 carbonyl oxygens. In the PEPCK-Mn2+-OAA complex, an alternate bound conformation of OAA is present. In this conformation, in addition to the previous interactions, the C1 carboxylate is directly coordinated to the active site Mn2+, displacing all of the waters coordinated to the metal in the holo-enzyme. In the PEPCK-Mn2+-GTP structure, the same water molecule displaced by the C1 carboxylate of OAA is displaced by one of the gamma-phosphate oxygens of the triphosphate nucleotide. The structures are consistent with a mechanism of direct in-line phosphoryl transfer, supported by the observed stereochemistry of the reaction. In the catalytically competent binding mode, the C1 carboxylate of OAA is sandwiched between R87 and R405 in an environment that would serve to facilitate decarboxylation. In the reverse reaction, these two arginines would form the CO2 binding site. Comparison of the Mn2+-OAA-Mn2+GDP and Mn2+-Mn2+GTP structures illustrates a marked difference in the bound conformations of the nucleotide substrates in which the GTP nucleotide is bound in a high-energy state resulting from the eclipsing of all three of the phosphoryl groups along the triphosphate chain. This contrasts a previously determined structure of PEPCK in complex with a triphosphate nucleotide analogue in which the analogue mirrors the conformation of GDP as opposed to GTP. Last, the structures illustrate a correlation between conformational changes in the P-loop, the nucleotide binding site, and the active site lid that are important for catalysis.

Structures of rat cytosolic PEPCK: insight into the mechanism of phosphorylation and decarboxylation of oxaloacetic acid.,Sullivan SM, Holyoak T Biochemistry. 2007 Sep 4;46(35):10078-88. Epub 2007 Aug 9. PMID:17685635<ref>PMID:17685635</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Phosphoenolpyruvate carboxykinase 3D structures|Phosphoenolpyruvate carboxykinase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Holyoak T]]
[[Category: Sullivan SM]]