1nux: Difference between revisions

Revision as of 03:00, 3 May 2008

Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate, Phosphate and inhibitory concentrations of Potassium (200mM)

OverviewOverview

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.

About this StructureAbout this Structure

1NUX is a Single protein structure of sequence from Sus scrofa. Full crystallographic information is available from OCA.

ReferenceReference

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 Page seeded by OCA on Sat May 3 03:00:40 2008

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OCA

@@ Line 1: / Line 1: @@
 [[Image:1nux.jpg|left|200px]]
- {{Structure
+<!--
-|PDB= 1nux |SIZE=350|CAPTION= <scene name='initialview01'>1nux</scene>, resolution 1.6&Aring;
+The line below this paragraph, containing "STRUCTURE_1nux", creates the "Structure Box" on the page.
-|SITE=
+You may change the PDB parameter (which sets the PDB file loaded into the applet)
-|LIGAND= <scene name='pdbligand=F6P:FRUCTOSE-6-PHOSPHATE'>F6P</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PO3:PHOSPHITE+ION'>PO3</scene>
+or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
-|ACTIVITY= <span class='plainlinks'>[http://en.wikipedia.org/wiki/Fructose-bisphosphatase Fructose-bisphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.3.11 3.1.3.11] </span>
+or leave the SCENE parameter empty for the default display.
-|GENE=
+-->
-|DOMAIN=
+{{STRUCTURE_1nux|  PDB=1nux  |  SCENE=  }}
-|RELATEDENTRY=[[1nuw|1NUW]], [[1nuy|1NUY]]
-|RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1nux FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nux OCA], [http://www.ebi.ac.uk/pdbsum/1nux PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1nux RCSB]</span>
-}}
 '''Fructose-1,6-Bisphosphatase Complex with Magnesium, Fructose-6-Phosphate, Phosphate and inhibitory concentrations of Potassium (200mM)'''
@@ Line 30: / Line 27: @@
 [[Category: Honzatko, R B.]]
 [[Category: Iancu, C V.]]
-[[Category: allosteric enzyme]]
+[[Category: Allosteric enzyme]]
-[[Category: bisphosphatase]]
+[[Category: Bisphosphatase]]
-[[Category: gluconeogenesis]]
+[[Category: Gluconeogenesis]]
-[[Category: hydrolase]]
+[[Category: Hydrolase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 03:00:40 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:35:53 2008''