ジャーナル: EMBO J / 年: 2008 タイトル: Recognition of aminoacyl-tRNA: a common molecular mechanism revealed by cryo-EM. 著者: Wen Li / Xabier Agirrezabala / Jianlin Lei / Lamine Bouakaz / Julie L Brunelle / Rodrigo F Ortiz-Meoz / Rachel Green / Suparna Sanyal / Måns Ehrenberg / Joachim Frank / 要旨: The accuracy of ribosomal translation is achieved by an initial selection and a proofreading step, mediated by EF-Tu, which forms a ternary complex with aminoacyl(aa)-tRNA. To study the binding modes ...The accuracy of ribosomal translation is achieved by an initial selection and a proofreading step, mediated by EF-Tu, which forms a ternary complex with aminoacyl(aa)-tRNA. To study the binding modes of different aa-tRNAs, we compared cryo-EM maps of the kirromycin-stalled ribosome bound with ternary complexes containing Phe-tRNA(Phe), Trp-tRNA(Trp), or Leu-tRNA(LeuI). The three maps suggest a common binding manner of cognate aa-tRNAs in their specific binding with both the ribosome and EF-Tu. All three aa-tRNAs have the same 'loaded spring' conformation with a kink and twist between the D-stem and anticodon stem. The three complexes are similarly integrated in an interaction network, extending from the anticodon loop through h44 and protein S12 to the EF-Tu-binding CCA end of aa-tRNA, proposed to signal cognate codon-anticodon interaction to the GTPase centre and tune the accuracy of aa-tRNA selection.
名称: 70S ribosome / タイプ: complex / ID: 1 / Name.synonym: 70S ribosome / 組換発現: No / Ribosome-details: ribosome-prokaryote: ALL
由来(天然)
生物種: Escherichia coli (大腸菌)
分子量
実験値: 2.8 MDa / 理論値: 2.8 MDa
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実験情報
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構造解析
手法
ネガティブ染色法, クライオ電子顕微鏡法
解析
単粒子再構成法
試料の集合状態
particle
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試料調製
濃度
0.03 mg/mL
緩衝液
pH: 7.3 詳細: Polymix buffer( 5 mM potassium phosphate (KH2PO4) pH 7.3, 5 mM NH4Cl, 95 mM KCl, 0.5 mM CaCl2, 8 mM putrescine, 1 mM spermidine, 1 mM DTE, 5 mM magnesium acetate)
染色
タイプ: NEGATIVE / 詳細: cryo
グリッド
詳細: 200 mesh
凍結
凍結剤: NITROGEN / チャンバー内湿度: 90 % / チャンバー内温度: 80 K / 装置: OTHER / 詳細: Vitrification instrument: vitrobot / 手法: Blot for 6 seconds
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電子顕微鏡法
顕微鏡
FEI TECNAI F20
温度
最低: 80.7 K / 最高: 80.7 K / 平均: 80.7 K
アライメント法
Legacy - 非点収差: corrected objective at 100,000 times magnification Legacy - Electron beam tilt params: no tilt