ジャーナル: Nat Struct Biol / 年: 2003 タイトル: Incorporation of aminoacyl-tRNA into the ribosome as seen by cryo-electron microscopy. 著者: Mikel Valle / Andrey Zavialov / Wen Li / Scott M Stagg / Jayati Sengupta / Rikke C Nielsen / Poul Nissen / Stephen C Harvey / Måns Ehrenberg / Joachim Frank / 要旨: Aminoacyl-tRNAs (aa-tRNAs) are delivered to the ribosome as part of the ternary complex of aa-tRNA, elongation factor Tu (EF-Tu) and GTP. Here, we present a cryo-electron microscopy (cryo-EM) study, ...Aminoacyl-tRNAs (aa-tRNAs) are delivered to the ribosome as part of the ternary complex of aa-tRNA, elongation factor Tu (EF-Tu) and GTP. Here, we present a cryo-electron microscopy (cryo-EM) study, at a resolution of approximately 9 A, showing that during the incorporation of the aa-tRNA into the 70S ribosome of Escherichia coli, the flexibility of aa-tRNA allows the initial codon recognition and its accommodation into the ribosomal A site. In addition, a conformational change observed in the GTPase-associated center (GAC) of the ribosomal 50S subunit may provide the mechanism by which the ribosome promotes a relative movement of the aa-tRNA with respect to EF-Tu. This relative rearrangement seems to facilitate codon recognition by the incoming aa-tRNA, and to provide the codon-anticodon recognition-dependent signal for the GTPase activity of EF-Tu. From these new findings we propose a mechanism that can explain the sequence of events during the decoding of mRNA on the ribosome.
70S bearing deacylated tRNAfMet in the P site and dipeptidyl MP-tRNA in the A site. Same complex as in project 138 but in the absence of Kirromicin. The Phe-tRNA is fully delivered to the A-site and after the peptide bond formation the dipeptidyl-tRNA stays in the A site. mRNA codes for MP-stop
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緩衝液
名称: Polymix buffer / pH: 7.5 / 詳細: Polymix buffer
試料
濃度: 32 mg/ml / 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES