2GQ1

Crystal Structure of Recombinant Type I Fructose-1,6-bisphosphatase from Escherichia coli Complexed with Sulfate Ions

2GQ1 の概要

• エントリーDOI: 10.2210/pdb2gq1/pdb
• 分子名称: Fructose-1,6-bisphosphatase, SULFATE ION (3 entities in total)
• 機能のキーワード: allosteric activator site, quaternary conformation, hydrolase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 37833.67

構造登録者

Hines, J.K.,Fromm, H.J.,Honzatko, R.B. (登録日: 2006-04-19, 公開日: 2006-05-02, 最終更新日: 2024-11-20)

主引用文献

Hines, J.K.,Fromm, H.J.,Honzatko, R.B.
Novel Allosteric Activation Site in Escherichia coli Fructose-1,6-bisphosphatase.
J.Biol.Chem., 281:18386-18393, 2006

PubMed Abstract: Fructose-1,6-bisphosphatase (FBPase) governs a key step in gluconeogenesis, the conversion of fructose 1,6-bisphosphate into fructose 6-phosphate. In mammals, the enzyme is subject to metabolic regulation, but regulatory mechanisms of bacterial FBPases are not well understood. Presented here is the crystal structure (resolution, 1.45A) of recombinant FBPase from Escherichia coli, the first structure of a prokaryotic Type I FBPase. The E. coli enzyme is a homotetramer, but in a quaternary state between the canonical R- and T-states of porcine FBPase. Phe(15) and residues at the C-terminal side of the first alpha-helix (helix H1) occupy the AMP binding pocket. Residues at the N-terminal side of helix H1 hydrogen bond with sulfate ions buried at a subunit interface, which in porcine FBPase undergoes significant conformational change in response to allosteric effectors. Phosphoenolpyruvate and sulfate activate E. coli FBPase by at least 300%. Key residues that bind sulfate anions are conserved among many heterotrophic bacteria, but are absent in FBPases of organisms that employ fructose 2,6-bisphosphate as a regulator. These observations suggest a new mechanism of regulation in the FBPase enzyme family: anionic ligands, most likely phosphoenolpyruvate, bind to allosteric activator sites, which in turn stabilize a tetramer and a polypeptide fold that obstructs AMP binding.

PubMed: 16670087
DOI: 10.1074/jbc.M602553200

実験手法

X-RAY DIFFRACTION (1.45 Å)