ジャーナル: Cell / 年: 2024 タイトル: Diatom pyrenoids are encased in a protein shell that enables efficient CO fixation. 著者: Ginga Shimakawa / Manon Demulder / Serena Flori / Akihiro Kawamoto / Yoshinori Tsuji / Hermanus Nawaly / Atsuko Tanaka / Rei Tohda / Tadayoshi Ota / Hiroaki Matsui / Natsumi Morishima / ...著者: Ginga Shimakawa / Manon Demulder / Serena Flori / Akihiro Kawamoto / Yoshinori Tsuji / Hermanus Nawaly / Atsuko Tanaka / Rei Tohda / Tadayoshi Ota / Hiroaki Matsui / Natsumi Morishima / Ryosuke Okubo / Wojciech Wietrzynski / Lorenz Lamm / Ricardo D Righetto / Clarisse Uwizeye / Benoit Gallet / Pierre-Henri Jouneau / Christoph Gerle / Genji Kurisu / Giovanni Finazzi / Benjamin D Engel / Yusuke Matsuda / 要旨: Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO fixation. Diatoms fix up to 20% of global CO, but their pyrenoids remain poorly characterized. ...Pyrenoids are subcompartments of algal chloroplasts that increase the efficiency of Rubisco-driven CO fixation. Diatoms fix up to 20% of global CO, but their pyrenoids remain poorly characterized. Here, we used in vivo photo-crosslinking to identify pyrenoid shell (PyShell) proteins, which we localized to the pyrenoid periphery of model pennate and centric diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana. In situ cryo-electron tomography revealed that pyrenoids of both diatom species are encased in a lattice-like protein sheath. Single-particle cryo-EM yielded a 2.4-Å-resolution structure of an in vitro TpPyShell1 lattice, which showed how protein subunits interlock. T. pseudonana TpPyShell1/2 knockout mutants had no PyShell sheath, altered pyrenoid morphology, and a high-CO requiring phenotype, with reduced photosynthetic efficiency and impaired growth under standard atmospheric conditions. The structure and function of the diatom PyShell provide a molecular view of how CO is assimilated in the ocean, a critical ecosystem undergoing rapid change.
平均露光時間: 2.631 sec. / 電子線照射量: 50 e/Å2 / フィルム・検出器のモデル: GATAN K3 (6k x 4k) / 撮影したグリッド数: 1 / 実像数: 5951 詳細: Images were collected in movie-mode at 52 frames per second
電子光学装置
エネルギーフィルター名称: GIF Bioquantum / エネルギーフィルタースリット幅: 20 eV 球面収差補正装置: Microscope was modified with a Cs corrector
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解析
EMソフトウェア
ID
名称
バージョン
カテゴリ
1
RELION
3.1
粒子像選択
2
SerialEM
画像取得
4
Gctf
CTF補正
7
Coot
モデルフィッティング
8
UCSF Chimera
モデルフィッティング
10
cryoSPARC
4.0.2
初期オイラー角割当
11
RELION
4
最終オイラー角割当
12
RELION
4
分類
13
RELION
4
3次元再構成
14
PHENIX
モデル精密化
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
らせん対称
回転角度/サブユニット: -56.07 ° / 軸方向距離/サブユニット: 3.59 Å / らせん対称軸の対称性: C1
粒子像の選択
選択した粒子像数: 5951
3次元再構成
解像度: 2.4 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 322887 / アルゴリズム: BACK PROJECTION / 対称性のタイプ: HELICAL