July 7, 2019  |  

Coupling of mRNA structure rearrangement to ribosome movement during bypassing of non-coding regions.

Authors: Chen, Jin and Coakley, Arthur and O'Connor, Michelle and Petrov, Alexey and O'Leary, Seán E and Atkins, John F and Puglisi, Joseph D

Nearly half of the ribosomes translating a particular bacteriophage T4 mRNA bypass a region of 50 nt, resuming translation 3' of this gap. How this large-scale, specific hop occurs and what determines whether a ribosome bypasses remain unclear. We apply single-molecule fluorescence with zero-mode waveguides to track individual Escherichia coli ribosomes during translation of T4's gene 60 mRNA. Ribosomes that bypass are characterized by a 10- to 20-fold longer pause in a non-canonical rotated state at the take-off codon. During the pause, mRNA secondary structure rearrangements are coupled to ribosome forward movement, facilitated by nascent peptide interactions that disengage the ribosome anticodon-codon interactions for slippage. Close to the landing site, the ribosome then scans mRNA in search of optimal base-pairing interactions. Our results provide a mechanistic and conformational framework for bypassing, highlighting a non-canonical ribosomal state to allow for mRNA structure refolding to drive large-scale ribosome movements. Copyright © 2015 Elsevier Inc. All rights reserved.

Journal: Cell
DOI: 10.1016/j.cell.2015.10.064
Year: 2015

Read Publication

Talk with an expert

If you have a question, need to check the status of an order, or are interested in purchasing an instrument, we're here to help.