5LZQ

Crystal structure of Thermotoga maritima sodium pumping membrane integral pyrophosphatase in complex with imidodiphosphate and magnesium, and with bound sodium ion

5LZQ の概要

• エントリーDOI: 10.2210/pdb5lzq/pdb
• 分子名称: K(+)-stimulated pyrophosphate-energized sodium pump, MAGNESIUM ION, IMIDODIPHOSPHORIC ACID, ... (5 entities in total)
• 機能のキーワード: pyrophosphatase, imidodiphosphate, transport protein
• 由来する生物種: Thermotoga maritima MSB8
• 細胞内の位置: Cell membrane ; Multi-pass membrane protein : Q9S5X0
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 157431.27

構造登録者

Wilkinson, C.,Kellosalo, J.,Kajander, T.,Goldman, A. (登録日: 2016-10-01, 公開日: 2016-12-14, 最終更新日: 2024-01-17)

主引用文献

Li, K.M.,Wilkinson, C.,Kellosalo, J.,Tsai, J.Y.,Kajander, T.,Jeuken, L.J.,Sun, Y.J.,Goldman, A.
Membrane pyrophosphatases from Thermotoga maritima and Vigna radiata suggest a conserved coupling mechanism.
Nat Commun, 7:13596-13596, 2016

PubMed Abstract: Membrane-bound pyrophosphatases (M-PPases), which couple proton/sodium ion transport to pyrophosphate synthesis/hydrolysis, are important in abiotic stress resistance and in the infectivity of protozoan parasites. Here, three M-PPase structures in different catalytic states show that closure of the substrate-binding pocket by helices 5-6 affects helix 13 in the dimer interface and causes helix 12 to move down. This springs a 'molecular mousetrap', repositioning a conserved aspartate and activating the nucleophilic water. Corkscrew motion at helices 6 and 16 rearranges the key ionic gate residues and leads to ion pumping. The pumped ion is above the ion gate in one of the ion-bound structures, but below it in the other. Electrometric measurements show a single-turnover event with a non-hydrolysable inhibitor, supporting our model that ion pumping precedes hydrolysis. We propose a complete catalytic cycle for both proton and sodium-pumping M-PPases, and one that also explains the basis for ion specificity.

PubMed: 27922000
DOI: 10.1038/ncomms13596

実験手法

X-RAY DIFFRACTION (3.495 Å)