EMDB/PDB/SASBDBから引用されている文献のデータベース

キーワード
構造解析手法	All X線回折 NMR 電子顕微鏡小角散乱中性子線回折線維回折粉末回折赤外分光 EPR FRET 理論モデルハイブリッド
著者・登録者
ジャーナル
IF	>30 >20 >10 >5 all

タイトル	Cryo-EM structure of gastric H+,K+-ATPase with a single occupied cation-binding site.
ジャーナル・号・ページ	Proc Natl Acad Sci U S A, Vol. 109, Issue 45, Page 18401-18406, Year 2012
掲載日	2012年11月6日
著者	Kazuhiro Abe / Kazutoshi Tani / Thomas Friedrich / Yoshinori Fujiyoshi /
PubMed 要旨	Gastric H(+),K(+)-ATPase is responsible for gastric acid secretion. ATP-driven H(+) uptake into the stomach is efficiently accomplished by the exchange of an equal amount of K(+), resulting in a ...Gastric H(+),K(+)-ATPase is responsible for gastric acid secretion. ATP-driven H(+) uptake into the stomach is efficiently accomplished by the exchange of an equal amount of K(+), resulting in a luminal pH close to 1. Because of the limited free energy available for ATP hydrolysis, the stoichiometry of transported cations is thought to vary from 2H(+)/2K(+) to 1H(+)/1K(+) per hydrolysis of one ATP molecule as the luminal pH decreases, although direct evidence for this hypothesis has remained elusive. Here, we show, using the phosphate analog aluminum fluoride (AlF) and a K(+) congener (Rb(+)), the 8-Å resolution structure of H(+),K(+)-ATPase in the transition state of dephosphorylation, (Rb(+))E2~AlF, which is distinct from the preceding Rb(+)-free E2P state. A strong density located in the transmembrane cation-binding site of (Rb(+))E2~AlF highly likely represents a single bound Rb(+) ion, which is clearly different from the Rb(+)-free E2AlF or K(+)-bound (K(+))E2~AlF structures. Measurement of radioactive (86)Rb(+) binding suggests that the binding stoichiometry varies depending on the pH, and approximately half of the amount of Rb(+) is bound under acidic crystallization conditions compared with at a neutral pH. These data represent structural and biochemical evidence for the 1H(+)/1K(+)/1ATP transport mode of H(+),K(+)-ATPase, which is a prerequisite for generation of the 10(6)-fold proton gradient in terms of thermodynamics. Together with the released E2P-stabilizing interaction between the β subunit's N terminus and the P domain observed in the (Rb(+))E2~AlF structure, we propose a refined vectorial transport model of H(+),K(+)-ATPase, which must prevail against the highly acidic state of the gastric lumen.
リンク	Proc Natl Acad Sci U S A / PubMed:23091039 / PubMed Central
手法	EM (電子線結晶学)
解像度	8.0 Å
構造データ	2219 2yn9 EMDB-2219: Cryo-EM structure of gastric H+,K+-ATPase with bound Rb+ PDB-2yn9: Cryo-EM structure of gastric H+,K+-ATPase with bound rubidium 手法: EM (電子線結晶学) / 解像度: 8.0 Å EMDB-2220: Cryo-EM structure of gastric H+,K+-ATPase with bound K+ 手法: EM (電子線結晶学) / 解像度: 8.0 Å
由来	sus scrofa (ブタ)
キーワード	HYDROLASE / P-TYPE ATPASE / PROTON PUMP