ジャーナル: Science / 年: 2019 タイトル: Mitoribosomal small subunit biogenesis in trypanosomes involves an extensive assembly machinery. 著者: Martin Saurer / David J F Ramrath / Moritz Niemann / Salvatore Calderaro / Céline Prange / Simone Mattei / Alain Scaiola / Alexander Leitner / Philipp Bieri / Elke K Horn / Marc Leibundgut / ...著者: Martin Saurer / David J F Ramrath / Moritz Niemann / Salvatore Calderaro / Céline Prange / Simone Mattei / Alain Scaiola / Alexander Leitner / Philipp Bieri / Elke K Horn / Marc Leibundgut / Daniel Boehringer / André Schneider / Nenad Ban / 要旨: Mitochondrial ribosomes (mitoribosomes) are large ribonucleoprotein complexes that synthesize proteins encoded by the mitochondrial genome. An extensive cellular machinery responsible for ribosome ...Mitochondrial ribosomes (mitoribosomes) are large ribonucleoprotein complexes that synthesize proteins encoded by the mitochondrial genome. An extensive cellular machinery responsible for ribosome assembly has been described only for eukaryotic cytosolic ribosomes. Here we report that the assembly of the small mitoribosomal subunit in involves a large number of factors and proceeds through the formation of assembly intermediates, which we analyzed by using cryo-electron microscopy. One of them is a 4-megadalton complex, referred to as the small subunit assemblosome, in which we identified 34 factors that interact with immature ribosomal RNA (rRNA) and recognize its functionally important regions. The assembly proceeds through large-scale conformational changes in rRNA coupled with successive incorporation of mitoribosomal proteins, providing an example for the complexity of the ribosomal assembly process in mitochondria.
凍結剤: ETHANE-PROPANE / チャンバー内湿度: 100 % / チャンバー内温度: 277 K / 装置: FEI VITROBOT MARK IV
詳細
Mitochondrial ribosomal small subunit middle assembly intermediate of wild-type Trypanosoma brucei brucei Lister strain 427
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電子顕微鏡法
顕微鏡
FEI TITAN KRIOS
撮影
フィルム・検出器のモデル: FEI FALCON III (4k x 4k) 検出モード: INTEGRATING / デジタル化 - サンプリング間隔: 14.0 µm / 撮影したグリッド数: 1 / 実像数: 13503 / 平均露光時間: 1.5 sec. / 平均電子線量: 75.0 e/Å2 詳細: Images were collected in movie-mode at 40 frames per second
ソフトウェア - 名称: Gctf (ver. 1.06) / 詳細: On the fly in RELION
初期モデル
モデルのタイプ: OTHER 詳細: The startup model was obtained from 3D classification of all particles classified as mt-SSU (mt-SSU initial reference was determined ab-initio using RELION 3D initial model routine based on SGD).
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 3.0.5)
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 3.0.5)
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原子モデル構築 1
詳細
Starting models of ribosomal proteins of the T. brucei mitochondrial ribosomal small subunit were taken from PDB 6HIW. Mitchondrial ribosomal small subunit assembly factors were built de novo.