1k3d
Phosphoenolpyruvate carboxykinase in complex with ADP and AlF3
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OverviewOverview
The mechanism of reversible transfer of the gamma-phosphate group of ATP, by Escherichia coli phosphoenolpyruvate carboxykinase (PCK) on to its, substrate is of great interest. It is known that metallofluorides are, accurate analogs of the transition state in the context of kinase, mechanisms. Therefore, two complexes of PCK, one with AlF(3), Mg(2+) and, ADP (complex I), the other with AlF(3), Mg(2+), ADP and pyruvate (complex, II) were crystallized. The X-ray crystal structures of these two complexes, were determined at 2.0 A resolution. The Al atom has trigonal bipyramidal, geometry that mimics the transition state of phosphoryl transfer. The Al, atom is at a distance of 2.8 A and 2.9 A from an oxygen atom of the, beta-phosphoryl group of ADP in complex I and II, respectively. A water, molecule in complex I and an oxygen atom of the pyruvate in complex II are, located along the axis of the trigonal bipyramid on the side opposite to, the beta-phosphoryl oxygen with respect to the equatorial plane, suggesting that the complexes are close mimics of the transition state., Along with the presence of positively charged species around the AlF(3), moiety, these results indicate that phosphoryl transfer occurs via a, direct displacement mechanism with associative qualities.
About this StructureAbout this Structure
1K3D is a Single protein structure of sequence from Escherichia coli with MG, ADP and AF3 as ligands. Active as Phosphoenolpyruvate carboxykinase (ATP), with EC number 4.1.1.49 Full crystallographic information is available from OCA.
ReferenceReference
The phosphoryl-transfer mechanism of Escherichia coli phosphoenolpyruvate carboxykinase from the use of AlF(3)., Sudom AM, Prasad L, Goldie H, Delbaere LT, J Mol Biol. 2001 Nov 16;314(1):83-92. PMID:11724534
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