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Structural basis for the transition from translation initiation to elongation by an 80S-eIF5B complex.

ABSTRACT: Recognition of a start codon by the initiator aminoacyl-tRNA determines the reading frame of messenger RNA (mRNA) translation by the ribosome. In eukaryotes, the GTPase eIF5B collaborates in the correct positioning of the initiator Met-tRNAiMet on the ribosome in the later stages of translation initiation, gating entrance into elongation. Leveraging the long residence time of eIF5B on the ribosome recently identified by single-molecule fluorescence measurements, we determine the cryoEM structure of the naturally long-lived ribosome complex with eIF5B and Met-tRNAiMet immediately before transition into elongation. The structure uncovers an unexpected, eukaryotic specific and dynamic fidelity checkpoint implemented by eIF5B in concert with components of the large ribosomal subunit.

SUBMITTER: Wang J

PROVIDER: S-EPMC7538418 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Structural basis for the transition from translation initiation to elongation by an 80S-eIF5B complex.

Wang Jinfan J Wang Jing J Shin Byung-Sik BS Kim Joo-Ran JR Dever Thomas E TE Puglisi Joseph D JD Fernández Israel S IS

Nature communications 20201006 1

Recognition of a start codon by the initiator aminoacyl-tRNA determines the reading frame of messenger RNA (mRNA) translation by the ribosome. In eukaryotes, the GTPase eIF5B collaborates in the correct positioning of the initiator Met-tRNA<sub>i</sub><sup>Met</sup> on the ribosome in the later stages of translation initiation, gating entrance into elongation. Leveraging the long residence time of eIF5B on the ribosome recently identified by single-molecule fluorescence measurements, we determin ...[more]

PMID: 33024099

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eIF5B gates the transition from translation initiation to elongation.

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