2XQS

Microscopic rotary mechanism of ion translocation in the Fo complex of ATP synthases

2XQS の概要

• エントリーDOI: 10.2210/pdb2xqs/pdb
• 関連するPDBエントリー: 2XQT 2XQU
• 分子名称: ATP SYNTHASE C CHAIN, CYMAL-4 (3 entities in total)
• 機能のキーワード: membrane protein, f1fo-atp synthase rotor, c-ring, ion (proton, h+)-translocation, n, n'- dicyclohexylcarbodiimide (dccd) inhibitor
• 由来する生物種: ARTHROSPIRA PLATENSIS
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 60279.49

構造登録者

Pogoryelov, D.,Krah, A.,Langer, J.,Yildiz, O.,Faraldo-Gomez, J.D.,Meier, T. (登録日: 2010-09-07, 公開日: 2010-10-27, 最終更新日: 2024-11-06)

主引用文献

Pogoryelov, D.,Krah, A.,Langer, J.,Yildiz, O.,Faraldo-Gomez, J.D.,Meier, T.
Microscopic Rotary Mechanism of Ion Translocation in the Fo Complex of ATP Synthases
Nat.Chem.Biol., 6:891-, 2010

PubMed Abstract: The microscopic mechanism of coupled c-ring rotation and ion translocation in F(1)F(o)-ATP synthases is unknown. Here we present conclusive evidence supporting the notion that the ability of c-rings to rotate within the F(o) complex derives from the interplay between the ion-binding sites and their nonhomogenous microenvironment. This evidence rests on three atomic structures of the c(15) rotor from crystals grown at low pH, soaked at high pH and, after N,N'-dicyclohexylcarbodiimide (DCCD) modification, resolved at 1.8, 3.0 and 2.2 Å, respectively. Alongside a quantitative DCCD-labeling assay and free-energy molecular dynamics calculations, these data demonstrate how the thermodynamic stability of the so-called proton-locked state is maximized by the lipid membrane. By contrast, a hydrophilic environment at the a-subunit-c-ring interface appears to unlock the binding-site conformation and promotes proton exchange with the surrounding solution. Rotation thus occurs as c-subunits stochastically alternate between these environments, directionally biased by the electrochemical transmembrane gradient.

PubMed: 20972431
DOI: 10.1038/NCHEMBIO.457

実験手法

X-RAY DIFFRACTION (3 Å)