ジャーナル: Elife / 年: 2015 タイトル: Structure and conformational states of the bovine mitochondrial ATP synthase by cryo-EM. 著者: Anna Zhou / Alexis Rohou / Daniel G Schep / John V Bason / Martin G Montgomery / John E Walker / Nikolaus Grigorieff / John L Rubinstein / 要旨: Adenosine triphosphate (ATP), the chemical energy currency of biology, is synthesized in eukaryotic cells primarily by the mitochondrial ATP synthase. ATP synthases operate by a rotary catalytic ...Adenosine triphosphate (ATP), the chemical energy currency of biology, is synthesized in eukaryotic cells primarily by the mitochondrial ATP synthase. ATP synthases operate by a rotary catalytic mechanism where proton translocation through the membrane-inserted FO region is coupled to ATP synthesis in the catalytic F1 region via rotation of a central rotor subcomplex. We report here single particle electron cryomicroscopy (cryo-EM) analysis of the bovine mitochondrial ATP synthase. Combining cryo-EM data with bioinformatic analysis allowed us to determine the fold of the a subunit, suggesting a proton translocation path through the FO region that involves both the a and b subunits. 3D classification of images revealed seven distinct states of the enzyme that show different modes of bending and twisting in the intact ATP synthase. Rotational fluctuations of the c8-ring within the FO region support a Brownian ratchet mechanism for proton-translocation-driven rotation in ATP synthases.
pH: 7.2 詳細: 20 mM Tris-HCl, 100 mM NaCl, 0.05% (wt/v) dodecylmaltoside, 2 mM ATP, 0.02% (wt/v) NaN3
グリッド
詳細: Homemade holey carbon on 400 square mesh Cu/Rh grid, glow-discharged 2 mins
凍結
凍結剤: ETHANE-PROPANE MIXTURE / チャンバー内湿度: 100 % / 装置: FEI VITROBOT MARK III / 手法: Blot for 27 seconds before plunging
-
電子顕微鏡法 #1
Microscopy ID
1
顕微鏡
FEI TITAN KRIOS
温度
平均: 80 K
アライメント法
Legacy - 非点収差: Objective lens astigmatism was corrected at 18,000x magnification (before detector post-magnification)
詳細
K2 Summit direct detector device (Gatan Inc.) operated in super-resolution mode with a 1.64 angstrom physical pixel and 0.82 angstrom super-resolution pixel. With no specimen present, the rate of exposure of the detector was 8 electrons/pixel/second. Exposure- fractionated movies of 20.1 s were recorded as stacks of 67 frames, so that selected specimen areas were exposed with a total of 60.3 electrons/square angstrom.
Legacy - 非点収差: Objective lens astigmatism was corrected at 18,000x magnification (before detector post-magnification)
詳細
K2 Summit direct detector device (Gatan Inc.) operated in super-resolution mode with a 1.64 angstrom physical pixel and 0.82 angstrom super-resolution pixel. With no specimen present, the rate of exposure of the detector was 8 electrons/pixel/second. Exposure- fractionated movies of 20.1 s were recorded as stacks of 67 frames, so that selected specimen areas were exposed with a total of 60.3 electrons/square angstrom.
Seven refined maps were aligned and averaged in real space.
CTF補正
詳細: Each particle
最終 再構成
想定した対称性 - 点群: C1 (非対称) / アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 9.0 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: Relion, FREALIGN 詳細: The resolution of this map was not determined because this map is a real space average of seven maps of the bovine ATP synthase aligned at their Fo region. 使用した粒子像数: 145055