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| | <StructureSection load='6mgi' size='340' side='right'caption='[[6mgi]], [[Resolution|resolution]] 2.99Å' scene=''> | | <StructureSection load='6mgi' size='340' side='right'caption='[[6mgi]], [[Resolution|resolution]] 2.99Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6mgi]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Maize Maize]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6MGI OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6MGI FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6mgi]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Zea_mays Zea mays]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6MGI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6MGI FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=G6P:ALPHA-D-GLUCOSE-6-PHOSPHATE'>G6P</scene>, <scene name='pdbligand=GLY:GLYCINE'>GLY</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PGA:2-PHOSPHOGLYCOLIC+ACID'>PGA</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.986Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ppc1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=4577 MAIZE])</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=G6P:ALPHA-D-GLUCOSE-6-PHOSPHATE'>G6P</scene>, <scene name='pdbligand=GLY:GLYCINE'>GLY</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=PGA:2-PHOSPHOGLYCOLIC+ACID'>PGA</scene></td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Phosphoenolpyruvate_carboxylase Phosphoenolpyruvate carboxylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.31 4.1.1.31] </span></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=6mgi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6mgi OCA], [https://pdbe.org/6mgi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6mgi RCSB], [https://www.ebi.ac.uk/pdbsum/6mgi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6mgi ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6mgi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6mgi OCA], [http://pdbe.org/6mgi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6mgi RCSB], [http://www.ebi.ac.uk/pdbsum/6mgi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6mgi ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/CAPP1_MAIZE CAPP1_MAIZE] Through the carboxylation of phosphoenolpyruvate (PEP) it forms oxaloacetate, a four-carbon dicarboxylic acid source for the tricarboxylic acid cycle. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | </div> | | </div> |
| | <div class="pdbe-citations 6mgi" style="background-color:#fffaf0;"></div> | | <div class="pdbe-citations 6mgi" style="background-color:#fffaf0;"></div> |
| | + | |
| | + | ==See Also== |
| | + | *[[Phosphoenolpyruvate carboxylase|Phosphoenolpyruvate carboxylase]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
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| | </StructureSection> | | </StructureSection> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Maize]] | + | [[Category: Zea mays]] |
| - | [[Category: Phosphoenolpyruvate carboxylase]]
| + | [[Category: Gonzalez-Segura L]] |
| - | [[Category: Gonzalez-Segura, L]] | + | [[Category: Munoz-Clares RA]] |
| - | [[Category: Munoz-Clares, R A]] | + | |
| - | [[Category: Allosteric activator]]
| + | |
| - | [[Category: C4 metabolism]]
| + | |
| - | [[Category: Lyase]]
| + | |
| - | [[Category: Pepc-c4]]
| + | |
| Structural highlights
6mgi is a 2 chain structure with sequence from Zea mays. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Method: | X-ray diffraction, Resolution 2.986Å |
| Ligands: | , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
CAPP1_MAIZE Through the carboxylation of phosphoenolpyruvate (PEP) it forms oxaloacetate, a four-carbon dicarboxylic acid source for the tricarboxylic acid cycle.
Publication Abstract from PubMed
Activation of phosphoenolpyruvate carboxylase (PEPC) enzymes by glucose 6-phosphate (G6P) and other phospho-sugars is of major physiological relevance. Previous kinetic, site-directed mutagenesis and crystallographic results are consistent with allosteric activation, but the existence of a G6P-allosteric site was questioned and competitive activation-in which G6P would bind to the active site eliciting the same positive homotropic effect as the substrate phosphoenolpyruvate (PEP)-was proposed. Here, we report the crystal structure of the PEPC-C4 isozyme from Zea mays with G6P well bound into the previously proposed allosteric site, unambiguously confirming its existence. To test its functionality, Asp239-which participates in a web of interactions of the protein with G6P-was changed to alanine. The D239A variant was not activated by G6P but, on the contrary, inhibited. Inhibition was also observed in the wild-type enzyme at concentrations of G6P higher than those producing activation, and probably arises from G6P binding to the active site in competition with PEP. The lower activity and cooperativity for the substrate PEP, lower activation by glycine and diminished response to malate of the D239A variant suggest that the heterotropic allosteric activation effects of free-PEP are also abolished in this variant. Together, our findings are consistent with both the existence of the G6P-allosteric site and its essentiality for the activation of PEPC enzymes by phosphorylated compounds. Furthermore, our findings suggest a central role of the G6P-allosteric site in the overall kinetics of these enzymes even in the absence of G6P or other phospho-sugars, because of its involvement in activation by free-PEP.
Structural and biochemical evidence of the glucose 6-phosphate-allosteric site of maize C4-phosphoenolpyruvate carboxylase: its importance in the overall enzyme kinetics.,Munoz-Clares RA, Gonzalez-Segura L, Juarez-Diaz JA, Mujica-Jimenez C Biochem J. 2020 Jun 12;477(11):2095-2114. doi: 10.1042/BCJ20200304. PMID:32459324[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Munoz-Clares RA, Gonzalez-Segura L, Juarez-Diaz JA, Mujica-Jimenez C. Structural and biochemical evidence of the glucose 6-phosphate-allosteric site of maize C4-phosphoenolpyruvate carboxylase: its importance in the overall enzyme kinetics. Biochem J. 2020 Jun 12;477(11):2095-2114. doi: 10.1042/BCJ20200304. PMID:32459324 doi:http://dx.doi.org/10.1042/BCJ20200304
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