4TTI

Crystal structure of double mutant E. Coli purine nucleoside phosphorylase with 4 FMC molecules

4TTI の概要

• エントリーDOI: 10.2210/pdb4tti/pdb
• 分子名称: Purine nucleoside phosphorylase DeoD-type, (1S)-1-(7-amino-1H-pyrazolo[4,3-d]pyrimidin-3-yl)-1,4-anhydro-D-ribitol, PHOSPHATE ION, ... (5 entities in total)
• 機能のキーワード: purine nucleoside phosphorylase, formicyn a, transferase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 155668.15

構造登録者

Stefanic, Z.,Bzowska, A. (登録日: 2014-06-21, 公開日: 2015-07-08, 最終更新日: 2023-12-20)

主引用文献

Stefanic, Z.,Narczyk, M.,Mikleusevic, G.,Kazazic, S.,Bzowska, A.,Luic, M.
Crystallographic snapshots of ligand binding to hexameric purine nucleoside phosphorylase and kinetic studies give insight into the mechanism of catalysis.
Sci Rep, 8:15427-15427, 2018

PubMed Abstract: Purine nucleoside phosphorylase (PNP) catalyses the cleavage of the glycosidic bond of purine nucleosides using phosphate instead of water as a second substrate. PNP from Escherichia coli is a homohexamer, build as a trimer of dimers, and each subunit can be in two conformations, open or closed. This conformational change is induced by the presence of phosphate substrate, and very likely a required step for the catalysis. Closing one active site strongly affects the others, by a yet unclear mechanism and order of events. Kinetic and ligand binding studies show strong negative cooperativity between subunits. Here, for the first time, we managed to monitor the sequence of nucleoside binding to individual subunits in the crystal structures of the wild-type enzyme, showing that first the closed sites, not the open ones, are occupied by the nucleoside. However, two mutations within the active site, Asp204Ala/Arg217Ala, are enough not only to significantly reduce the effectiveness of the enzyme, but also reverse the sequence of the nucleoside binding. In the mutant the open sites, neighbours in a dimer of those in the closed conformation, are occupied as first. This demonstrates how important for the effective catalysis of Escherichia coli PNP is proper subunit cooperation.

PubMed: 30337572
DOI: 10.1038/s41598-018-33723-1

実験手法

X-RAY DIFFRACTION (1.89 Å)