7EPQ

Crystal structure of exopolyphosphatase (PPX) from Porphyromonas gingivalis in complex with sulfate and magnesium ions

7EPQ の概要

• エントリーDOI: 10.2210/pdb7epq/pdb
• 分子名称: Putative exopolyphosphatase, SULFATE ION, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: polyphosphate, exopolyphosphatase, complex, ppx/gppa, metal binding protein
• 由来する生物種: Porphyromonas gingivalis ATCC 33277
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 69346.88

構造登録者

Zhang, A. (登録日: 2021-04-27, 公開日: 2022-05-11, 最終更新日: 2023-11-29)

主引用文献

Zhang, A.,Lu, Z.,Xu, Y.,Qi, T.,Li, W.,Zhang, L.,Cui, Z.
The structure of exopolyphosphatase (PPX) from Porphyromonas gingivalis in complex with substrate analogs and magnesium ions reveals the basis for polyphosphate processivity.
J.Struct.Biol., 213:107767-107767, 2021

PubMed Abstract: The enzymes exopolyphosphatase/guanosine pentaphosphate phosphohydrolase (PPX/GppA) play important roles in the bacterial stringent response. PPX degrades inorganic polyphosphate (polyP), a polymer composed of a few to hundreds of phosphate residues supporting cell survival in the stationary phase. The crystal structure of PPX from Porphyromonas gingivalis (PgPPX) in complex with catalytic magnesium ions and several sulfate ions was solved. PgPPX contained two domains and represented a "closed" configuration. Four sulfate ions forming a linear dispersed chain were observed in the aqueduct of the PPX dimer, which the long polyP chain most likely occupied. The side chain of R255 stretched into the cavity where polyP could be located, obstructing the entrance of larger substrates such as NTP and NDP. This study provided the first view into the structure of the PPX/GppA homolog in complex with magnesium ions and substrate analogs and explained how PgPPX implemented its functionality.

PubMed: 34214602
DOI: 10.1016/j.jsb.2021.107767

実験手法

X-RAY DIFFRACTION (2.2 Å)