1NUW

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

1NUW の概要

• エントリーDOI: 10.2210/pdb1nuw/pdb
• 関連するPDBエントリー: 1NUX 1NUY
• 分子名称: Fructose-1,6-bisphosphatase, 6-O-phosphono-beta-D-fructofuranose, PHOSPHITE ION, ... (5 entities in total)
• 機能のキーワード: bisphosphatase, allosteric enzymes, gluconeogenesis, hydrolase
• 由来する生物種: Sus scrofa (pig)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37127.54

構造登録者

Choe, J.,Iancu, C.V.,Fromm, H.J.,Honzatko, R.B. (登録日: 2003-02-01, 公開日: 2003-07-08, 最終更新日: 2023-10-25)

主引用文献

Choe, J.Y.,Iancu, C.V.,Fromm, H.J.,Honzatko, R.B.
Metaphosphate in the active site of fructose-1,6-bisphosphatase
J.BIOL.CHEM., 278:16015-16020, 2003

PubMed Abstract: 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.

PubMed: 12595528
DOI: 10.1074/jbc.M212395200

実験手法

X-RAY DIFFRACTION (1.3 Å)