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Post-termination Ribosome Intermediate Acts as the Gateway to Ribosome Recycling.

ABSTRACT: During termination of translation, the nascent peptide is first released from the ribosome, which must be subsequently disassembled into subunits in a process known as ribosome recycling. In bacteria, termination and recycling are mediated by the translation factors RF, RRF, EF-G, and IF3, but their precise roles have remained unclear. Here, we use single-molecule fluorescence to track the conformation and composition of the ribosome in real time during termination and recycling. Our results show that peptide release by RF induces a rotated ribosomal conformation. RRF binds to this rotated intermediate to form the substrate for EF-G that, in turn, catalyzes GTP-dependent subunit disassembly. After the 50S subunit departs, IF3 releases the deacylated tRNA from the 30S subunit, thus preventing reassembly of the 70S ribosome. Our findings reveal the post-termination rotated state as the crucial intermediate in the transition from termination to recycling.

SUBMITTER: Prabhakar A

PROVIDER: S-EPMC5555083 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature

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Post-termination Ribosome Intermediate Acts as the Gateway to Ribosome Recycling.

Prabhakar Arjun A Capece Mark C MC Petrov Alexey A Choi Junhong J Puglisi Joseph D JD

Cell reports 20170701 1

During termination of translation, the nascent peptide is first released from the ribosome, which must be subsequently disassembled into subunits in a process known as ribosome recycling. In bacteria, termination and recycling are mediated by the translation factors RF, RRF, EF-G, and IF3, but their precise roles have remained unclear. Here, we use single-molecule fluorescence to track the conformation and composition of the ribosome in real time during termination and recycling. Our results sho ...[more]

PMID: 28683310

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