ジャーナル: Nat Commun / 年: 2025 タイトル: Structurally heterogeneous ribosomes cooperate in protein synthesis in bacterial cells. 著者: Karla Helena-Bueno / Sophie Kopetschke / Sebastian Filbeck / Lewis I Chan / Sonia Birsan / Arnaud Baslé / Maisie Hudson / Stefan Pfeffer / Chris H Hill / Sergey V Melnikov / 要旨: Ribosome heterogeneity is a paradigm in biology, pertaining to the existence of structurally distinct populations of ribosomes within a single organism or cell. This concept suggests that ...Ribosome heterogeneity is a paradigm in biology, pertaining to the existence of structurally distinct populations of ribosomes within a single organism or cell. This concept suggests that structurally distinct pools of ribosomes have different functional properties and may be used to translate specific mRNAs. However, it is unknown to what extent structural heterogeneity reflects genuine functional specialization rather than stochastic variations in ribosome assembly. Here, we address this question by combining cryo-electron microscopy and tomography to observe individual structurally heterogeneous ribosomes in bacterial cells. We show that 70% of ribosomes in Psychrobacter urativorans contain a second copy of the ribosomal protein bS20 at a previously unknown binding site on the large ribosomal subunit. We then determine that this second bS20 copy appears to be functionally neutral. This demonstrates that ribosome heterogeneity does not necessarily lead to functional specialization, even when it involves significant variations such as the presence or absence of a ribosomal protein. Instead, we show that heterogeneous ribosomes can cooperate in general protein synthesis rather than specialize in translating discrete populations of mRNA.
A: 10604.544 Å / B: 14912.64 Å / C: 4660.2 Å α=β=γ: 90.0 °
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添付データ
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試料の構成要素
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全体 : Tomogram of cryo-FIB milled Psychrobacter urativorans grown at ph...
全体
名称: Tomogram of cryo-FIB milled Psychrobacter urativorans grown at physiological conditions
要素
細胞: Tomogram of cryo-FIB milled Psychrobacter urativorans grown at physiological conditions
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超分子 #1: Tomogram of cryo-FIB milled Psychrobacter urativorans grown at ph...
超分子
名称: Tomogram of cryo-FIB milled Psychrobacter urativorans grown at physiological conditions タイプ: cell / ID: 1 / 親要素: 0
由来(天然)
生物種: Psychrobacter urativorans (バクテリア)
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実験情報
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構造解析
手法
クライオ電子顕微鏡法
解析
電子線トモグラフィー法
試料の集合状態
cell
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試料調製
緩衝液
pH: 7
凍結
凍結剤: ETHANE
切片作成
集束イオンビーム - 装置: OTHER / 集束イオンビーム - イオン: OTHER / 集束イオンビーム - 電圧: 13 / 集束イオンビーム - 電流: 0.01 / 集束イオンビーム - 時間: 600 / 集束イオンビーム - 温度: 92 K / 集束イオンビーム - Initial thickness: 2000 / 集束イオンビーム - 最終 厚さ: 140 集束イオンビーム - 詳細: The value given for _em_focused_ion_beam.instrument is FEI Aquilos2. This is not in a list of allowed values {'OTHER', 'DB235'} so OTHER is written into the XML file.
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電子顕微鏡法
顕微鏡
TFS KRIOS
撮影
フィルム・検出器のモデル: GATAN K3 BIOCONTINUUM (6k x 4k) 平均電子線量: 3.6 e/Å2