2ZXE

Crystal structure of the sodium - potassium pump in the E2.2K+.Pi state

2ZXE の概要

• エントリーDOI: 10.2210/pdb2zxe/pdb
• 関連するPDBエントリー: 1WPG
• 分子名称: Na, K-ATPase alpha subunit, Na+,K+-ATPase beta subunit, Phospholemman-like protein, ... (10 entities in total)
• 機能のキーワード: membrane protein, ion pump, atpase, k+ binding, haloacid dehydrogenease superfamily, phosphate analogue, atp-binding, hydrolase, ion transport, nucleotide-binding, phosphoprotein, hydrolase-transport protein complex, hydrolase/transport protein
• 由来する生物種: Squalus acanthias (Spiny dogfish); 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 157985.62

構造登録者

Shinoda, T.,Ogawa, H.,Cornelius, F.,Toyoshima, C. (登録日: 2008-12-22, 公開日: 2009-05-19, 最終更新日: 2024-11-06)

主引用文献

Shinoda, T.,Ogawa, H.,Cornelius, F.,Toyoshima, C.
Crystal structure of the sodium - potassium pump at 2.4 A resolution
Nature, 459:446-450, 2009

PubMed Abstract: Sodium-potassium ATPase is an ATP-powered ion pump that establishes concentration gradients for Na(+) and K(+) ions across the plasma membrane in all animal cells by pumping Na(+) from the cytoplasm and K(+) from the extracellular medium. Such gradients are used in many essential processes, notably for generating action potentials. Na(+), K(+)-ATPase is a member of the P-type ATPases, which include sarcoplasmic reticulum Ca(2+)-ATPase and gastric H(+), K(+)-ATPase, among others, and is the target of cardiac glycosides. Here we describe a crystal structure of this important ion pump, from shark rectal glands, consisting of alpha- and beta-subunits and a regulatory FXYD protein, all of which are highly homologous to human ones. The ATPase was fixed in a state analogous to E2.2K(+).P(i), in which the ATPase has a high affinity for K(+) and still binds P(i), as in the first crystal structure of pig kidney enzyme at 3.5 A resolution. Clearly visualized now at 2.4 A resolution are coordination of K(+) and associated water molecules in the transmembrane binding sites and a phosphate analogue (MgF(4)(2-)) in the phosphorylation site. The crystal structure shows that the beta-subunit has a critical role in K(+) binding (although its involvement has previously been suggested) and explains, at least partially, why the homologous Ca(2+)-ATPase counter-transports H(+) rather than K(+), despite the coordinating residues being almost identical.

PubMed: 19458722
DOI: 10.1038/nature07939

実験手法

X-RAY DIFFRACTION (2.4 Å)