2AU8

Catalytic intermediate structure of inorganic pyrophosphatase

2AU8 の概要

• エントリーDOI: 10.2210/pdb2au8/pdb
• 関連するPDBエントリー: 2AU6 2AU7 2AU9
• 分子名称: Inorganic pyrophosphatase, PHOSPHATE ION, MANGANESE (II) ION, ... (6 entities in total)
• 機能のキーワード: hydrolase, intermediate, inorganic pyrophosphatase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm: P0A7A9
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20029.35

構造登録者

Samygina, V.R.,Popov, A.N.,Avaeva, S.M.,Bartunik, H.D. (登録日: 2005-08-27, 公開日: 2006-08-29, 最終更新日: 2023-10-25)

主引用文献

Samygina, V.R.,Moiseev, V.M.,Rodina, E.V.,Vorobyeva, N.N.,Popov, A.N.,Kurilova, S.A.,Nazarova, T.I.,Avaeva, S.M.,Bartunik, H.D.
Reversible inhibition of Escherichia coli inorganic pyrophosphatase by fluoride: trapped catalytic intermediates in cryo-crystallographic studies
J.Mol.Biol., 366:1305-1317, 2007

PubMed Abstract: Here, we describe high-resolution X-ray structures of Escherichia coli inorganic pyrophosphatase (E-PPase) complexed with the substrate, magnesium, or manganese pyrophosphate. The structures correspond to steps in the catalytic synthesis of enzyme-bound pyrophosphate (PP(i)) in the presence of fluoride as an inhibitor of hydrolysis. The catalytic reaction intermediates were trapped applying a new method that we developed for initiating hydrolytic activity in the E-PPase crystal. X-ray structures were obtained for three consecutive states of the enzyme in the course of hydrolysis. Comparative analysis of these structures showed that the Mn2+-supported hydrolysis of the phosphoanhydride bond is followed by a fast release of the leaving phosphate from the P1 site. The electrophilic phosphate P2 is trapped in the "down" conformation. Its movement into the "up" position most likely represents the rate-limiting step of Mn2+-supported hydrolysis. We further determined the crystal structure of the Arg43Gln mutant variant of E-PPase complexed with one phosphate and four Mn ions.

PubMed: 17196979
DOI: 10.1016/j.jmb.2006.11.082

実験手法

X-RAY DIFFRACTION (1.65 Å)