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The structural basis for release-factor activation during translation termination revealed by time-resolved cryogenic electron microscopy.

ABSTRACT: When the ribosome encounters a stop codon, it recruits a release factor (RF) to hydrolyze the ester bond between the peptide chain and tRNA. RFs have structural motifs that recognize stop codons in the decoding center and a GGQ motif for induction of hydrolysis in the peptidyl transfer center 70?Å away. Surprisingly, free RF2 is compact, with only 20?Å between its codon-reading and GGQ motifs. Cryo-EM showed that ribosome-bound RFs have extended structures, suggesting that RFs are compact when entering the ribosome and then extend their structures upon stop codon recognition. Here we use time-resolved cryo-EM to visualize transient compact forms of RF1 and RF2 at 3.5 and 4?Å resolution, respectively, in the codon-recognizing ribosome complex on the native pathway. About 25% of complexes have RFs in the compact state at 24?ms reaction time, and within 60?ms virtually all ribosome-bound RFs are transformed to their extended forms.

SUBMITTER: Fu Z

PROVIDER: S-EPMC6561943 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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The structural basis for release-factor activation during translation termination revealed by time-resolved cryogenic electron microscopy.

Fu Ziao Z Indrisiunaite Gabriele G Kaledhonkar Sandip S Shah Binita B Sun Ming M Chen Bo B Grassucci Robert A RA Ehrenberg Måns M Frank Joachim J

Nature communications 20190612 1

When the ribosome encounters a stop codon, it recruits a release factor (RF) to hydrolyze the ester bond between the peptide chain and tRNA. RFs have structural motifs that recognize stop codons in the decoding center and a GGQ motif for induction of hydrolysis in the peptidyl transfer center 70 Å away. Surprisingly, free RF2 is compact, with only 20 Å between its codon-reading and GGQ motifs. Cryo-EM showed that ribosome-bound RFs have extended structures, suggesting that RFs are compact when e ...[more]

PMID: 31189921

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Dataset Information

The structural basis for release-factor activation during translation termination revealed by time-resolved cryogenic electron microscopy.

Publications

The structural basis for release-factor activation during translation termination revealed by time-resolved cryogenic electron microscopy.

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