1nuw

Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate and Phosphate at pH 9.6

spinqualitylabelsall models 1nuw, resolution 1.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1nuw is a 1 chain structure with sequence from Sus scrofa. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.3Å Ligands: F6P, MG, PO3 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function F16P1_PIG Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The hydrolysis of a phosphate ester can proceed through an intermediate of metaphosphate (dissociative mechanism) or through a trigonal bipryamidal transition state (associative mechanism). Model systems in solution support the dissociative pathway, whereas most enzymologists favor an associative mechanism for enzyme-catalyzed reactions. Crystals of fructose-1,6-bisphosphatase grow from an equilibrium mixture of substrates and products at near atomic resolution (1.3 A). At neutral pH, products of the reaction (orthophosphate and fructose 6-phosphate) bind to the active site in a manner consistent with an associative reaction pathway; however, in the presence of inhibitory concentrations of K+ (200 mm), or at pH 9.6, metaphosphate and water (or OH-) are in equilibrium with orthophosphate. Furthermore, one of the magnesium cations in the pH 9.6 complex resides in an alternative position, and suggests the possibility of metal cation migration as the 1-phosphoryl group of the substrate undergoes hydrolysis. To the best of our knowledge, the crystal structures reported here represent the first direct observation of metaphosphate in a condensed phase and may provide the structural basis for fundamental changes in the catalytic mechanism of fructose-1,6-bisphosphatase in response to pH and different metal cation activators. Metaphosphate in the active site of fructose-1,6-bisphosphatase.,Choe JY, Iancu CV, Fromm HJ, Honzatko RB J Biol Chem. 2003 May 2;278(18):16015-20. Epub 2003 Feb 20. PMID:12595528 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Fructose-1%2C6-bisphosphatase 3D structures

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