ジャーナル: Nat Commun / 年: 2022 タイトル: Cryo-EM structures of thylakoid-located voltage-dependent chloride channel VCCN1. 著者: Tatsuya Hagino / Takafumi Kato / Go Kasuya / Kan Kobayashi / Tsukasa Kusakizako / Shin Hamamoto / Tomoaki Sobajima / Yuichiro Fujiwara / Keitaro Yamashita / Hisashi Kawasaki / Andrés D ...著者: Tatsuya Hagino / Takafumi Kato / Go Kasuya / Kan Kobayashi / Tsukasa Kusakizako / Shin Hamamoto / Tomoaki Sobajima / Yuichiro Fujiwara / Keitaro Yamashita / Hisashi Kawasaki / Andrés D Maturana / Tomohiro Nishizawa / Osamu Nureki / 要旨: In the light reaction of plant photosynthesis, modulation of electron transport chain reactions is important to maintain the efficiency of photosynthesis under a broad range of light intensities. ...In the light reaction of plant photosynthesis, modulation of electron transport chain reactions is important to maintain the efficiency of photosynthesis under a broad range of light intensities. VCCN1 was recently identified as a voltage-gated chloride channel residing in the thylakoid membrane, where it plays a key role in photoreaction tuning to avoid the generation of reactive oxygen species (ROS). Here, we present the cryo-EM structures of Malus domestica VCCN1 (MdVCCN1) in nanodiscs and detergent at 2.7 Å and 3.0 Å resolutions, respectively, and the structure-based electrophysiological analyses. VCCN1 structurally resembles its animal homolog, bestrophin, a Ca-gated anion channel. However, unlike bestrophin channels, VCCN1 lacks the Ca-binding motif but instead contains an N-terminal charged helix that is anchored to the lipid membrane through an additional amphipathic helix. Electrophysiological experiments demonstrate that these structural elements are essential for the channel activity, thus revealing the distinct activation mechanism of VCCN1.
電子線照射量: 50 e/Å2 / 検出モード: COUNTING フィルム・検出器のモデル: FEI FALCON III (4k x 4k) 撮影したグリッド数: 1 / 実像数: 1161
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解析
ソフトウェア
名称: REFMAC / バージョン: 5.8.0274 / 分類: 精密化
EMソフトウェア
ID
名称
バージョン
カテゴリ
4
CTFFIND
4.1.13
CTF補正
10
RELION
3
初期オイラー角割当
11
RELION
3
最終オイラー角割当
12
RELION
3
分類
13
RELION
3
3次元再構成
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
粒子像の選択
選択した粒子像数: 322637
対称性
点対称性: C5 (5回回転対称)
3次元再構成
解像度: 3 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 117986 / 対称性のタイプ: POINT
精密化
解像度: 3→119.974 Å / Cor.coef. Fo:Fc: 0.785 / WRfactor Rwork: 0.3593 / SU B: 8.766 / SU ML: 0.163 / Average fsc overall: 0.9037 / Average fsc work: 0.9037 / ESU R: 0.19 / 詳細: Hydrogens have been added in their riding positions