8B23

Time-resolved structure of K+-dependent Na+-PPase from Thermotoga maritima 600-seconds post reaction initiation with Na+

8B23 の概要

• エントリーDOI: 10.2210/pdb8b23/pdb
• 分子名称: K(+)-stimulated pyrophosphate-energized sodium pump, DIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: membrane bound pyrophosphatase, membrane protein, enzyme, complex
• 由来する生物種: Thermotoga maritima
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 156705.45

構造登録者

Strauss, J.,Vidilaseris, K.,Goldman, A. (登録日: 2022-09-12, 公開日: 2024-01-17, 最終更新日: 2026-03-04)

主引用文献

Strauss, J.,Wilkinson, C.,Vidilaseris, K.,de Castro Ribeiro, O.M.,Liu, J.,Hillier, J.,Wichert, M.,Malinen, A.M.,Gehl, B.,Jeuken, L.J.,Pearson, A.R.,Goldman, A.
Functional and structural asymmetry suggest a unifying principle for catalysis in membrane-bound pyrophosphatases.
Embo Rep., 25:853-875, 2024

PubMed Abstract: Membrane-bound pyrophosphatases (M-PPases) are homodimeric primary ion pumps that couple the transport of Na- and/or H across membranes to the hydrolysis of pyrophosphate. Their role in the virulence of protist pathogens like Plasmodium falciparum makes them an intriguing target for structural and functional studies. Here, we show the first structure of a K-independent M-PPase, asymmetric and time-dependent substrate binding in time-resolved structures of a K-dependent M-PPase and demonstrate pumping-before-hydrolysis by electrometric studies. We suggest how key residues in helix 12, 13, and the exit channel loops affect ion selectivity and K-activation due to a complex interplay of residues that are involved in subunit-subunit communication. Our findings not only explain ion selectivity in M-PPases but also why they display half-of-the-sites reactivity. Based on this, we propose, for the first time, a unified model for ion-pumping, hydrolysis, and energy coupling in all M-PPases, including those that pump both Na and H.

PubMed: 38182815
DOI: 10.1038/s44319-023-00037-x

実験手法

X-RAY DIFFRACTION (3.84 Å)