Conformational control of translation termination on the 70S ribosome

Svidritskiy, E.; Korostelev, A. A.

doi:10.1101/226837

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bioRxiv · 10.1101/226837

Conformational control of translation termination on the 70S ribosome

Svidritskiy, E.·Korostelev, A. A.

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Abstract

Translation termination ensures proper lengths of cellular proteins. During termination, release factor (RF) recognizes a stop codon and catalyzes peptide release. Conformational changes in RF are thought to underlie accurate translation termination. If true, the release factor should bind the A-site codon in inactive (compact) conformation(s), but structural studies of ribosome termination complexes have only captured RFs in an extended, active conformation. Here, we identify a hyper-accurate RF1 variant, and present crystal structures of 70S termination complexes that suggest a structural pathway for RF1 activation. In the presence of blasticidin S, the catalytic domain of RF1 is removed from the peptidyl-transferase center, whereas the codon-recognition domain is fully engaged in stop-codon recognition in the decoding center. RF1 codon recognition induces decoding-center rearrangements that precede accommodation of the catalytic domain. Our findings suggest how structural dynamics of RF1 and the ribosome coordinate stop-codon recognition with peptide release, ensuring accurate translation termination.

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Svidritskiy, E., Korostelev, A. A.. 2017-11-29. Conformational control of translation termination on the 70S ribosome. https://doi.org/10.1101/226837

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