National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM079238
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM115327-Tan
米国
引用
ジャーナル: Elife / 年: 2022 タイトル: Didemnin B and ternatin-4 differentially inhibit conformational changes in eEF1A required for aminoacyl-tRNA accommodation into mammalian ribosomes. 著者: Manuel F Juette / Jordan D Carelli / Emily J Rundlet / Alan Brown / Sichen Shao / Angelica Ferguson / Michael R Wasserman / Mikael Holm / Jack Taunton / Scott C Blanchard / 要旨: Rapid and accurate mRNA translation requires efficient codon-dependent delivery of the correct aminoacyl-tRNA (aa-tRNA) to the ribosomal A site. In mammals, this fidelity-determining reaction is ...Rapid and accurate mRNA translation requires efficient codon-dependent delivery of the correct aminoacyl-tRNA (aa-tRNA) to the ribosomal A site. In mammals, this fidelity-determining reaction is facilitated by the GTPase elongation factor-1 alpha (eEF1A), which escorts aa-tRNA as an eEF1A(GTP)-aa-tRNA ternary complex into the ribosome. The structurally unrelated cyclic peptides didemnin B and ternatin-4 bind to the eEF1A(GTP)-aa-tRNA ternary complex and inhibit translation but have different effects on protein synthesis in vitro and in vivo. Here, we employ single-molecule fluorescence imaging and cryogenic electron microscopy to determine how these natural products inhibit translational elongation on mammalian ribosomes. By binding to a common site on eEF1A, didemnin B and ternatin-4 trap eEF1A in an intermediate state of aa-tRNA selection, preventing eEF1A release and aa-tRNA accommodation on the ribosome. We also show that didemnin B and ternatin-4 exhibit distinct effects on the dynamics of aa-tRNA selection that inform on observed disparities in their inhibition efficacies and physiological impacts. These integrated findings underscore the value of dynamics measurements in assessing the mechanism of small-molecule inhibition and highlight potential of single-molecule methods to reveal how distinct natural products differentially impact the human translation mechanism.
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 277 K / 装置: FEI VITROBOT MARK III
詳細
Pull downs of ribosomes from in vitro translation reactions of a transcript encoding 3x Flag-tagged KRas in rabbit reticulocyte lysate (RRL) in the presence of 1 uM ternatin-4.
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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 II (4k x 4k) 検出モード: COUNTING / 実像数: 1422 / 平均露光時間: 1.0 sec. / 平均電子線量: 40.0 e/Å2
電子線
加速電圧: 300 kV / 電子線源: FIELD EMISSION GUN
電子光学系
照射モード: OTHER / 撮影モード: BRIGHT FIELD 最大 デフォーカス(公称値): 9.200000000000001 µm 最小 デフォーカス(公称値): 0.8 µm / 倍率(公称値): 135000