Document Type
Article
Publication Date
9-29-2017
Abstract
Bacterial ribosome recycling requires breakdown of the post-termination complex (PoTC), comprising a messenger RNA (mRNA) and an uncharged transfer RNA (tRNA) cognate to the terminal mRNA codon bound to the 70S ribosome. The translation factors, elongation factor G and ribosome recycling factor, are known to be required for recycling, but there is controversy concerning whether these factors act primarily to effect the release of mRNA and tRNA from the ribosome, with the splitting of the ribosome into subunits being somewhat dispensable, or whether their main function is to catalyze the splitting reaction, which necessarily precedes mRNA and tRNA release. Here, we utilize three assays directly measuring the rates of mRNA and tRNA release and of ribosome splitting in several model PoTCs. Our results largely reconcile these previously held views. We demonstrate that, in the absence of an upstream Shine-Dalgarno (SD) sequence, PoTC breakdown proceeds in the order: mRNA release followed by tRNA release and then by 70S splitting. By contrast, in the presence of an SD sequence all three processes proceed with identical apparent rates, with the splitting step likely being rate-determining. Our results are consistent with ribosome profiling results demonstrating the influence of upstream SD-like sequences on ribosome occupancy at or just before the mRNA stop codon.
Recommended Citation
Chen, Yuanwei; Kaji, Akira; Kaji, Hideko; and Cooperman, Barry S., "The kinetic mechanism of bacterial ribosome recycling." (2017). Department of Biochemistry and Molecular Biology Faculty Papers. Paper 129.
https://jdc.jefferson.edu/bmpfp/129
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
PubMed ID
28973468
Comments
This article has been peer reviewed. It is the author’s final published version in Nucleic Acids Research
Volume 45, Issue 17, September 2017, Pages 10168-10177.
The published version is available at DOI: 10.1093/nar/gkx694. Copyright © Chen et al.