Mechanism of ribosome rescue by ArfA and RF2.

Citation data:

eLife, ISSN: 2050-084X, Vol: 6

Publication Year:
2017
Usage 33
Downloads 26
Abstract Views 7
Captures 1
Exports-Saves 1
Social Media 16
Tweets 16
Citations 11
Citation Indexes 11
Repository URL:
https://escholarship.umassmed.edu/oapubs/3114
PMID:
28300532
DOI:
10.7554/elife.23687; 10.7554/elife.23687.016; 10.7554/elife.23687.015; 10.7554/elife.23687.014; 10.7554/elife.23687.002; 10.7554/elife.23687.009; 10.7554/elife.23687.013; 10.7554/elife.23687.001; 10.7554/elife.23687.008; 10.7554/elife.23687.026; 10.7554/elife.23687.025
Author(s):
Demo, Gabriel; Svidritskiy, Egor; Madireddy, Rohini; Diaz-Avalos, Ruben; Grant, Timothy; Grigorieff, Nikolaus; Sousa, Duncan; Korostelev, Andrei A.
Publisher(s):
eLife Sciences Publications, Ltd; eLife Sciences Organisation, Ltd.
Tags:
Neuroscience; Biochemistry, Genetics and Molecular Biology; Immunology and Microbiology; ArfA; E. coli; biochemistry; biophysics; release factor 2; ribosome rescue; stalled ribosome; stop-codon-independent termination; structural biology; Biophysics; Structural Biology
Most Recent Tweet View All Tweets
article description
ArfA rescues ribosomes stalled on truncated mRNAs by recruiting release factor RF2, which normally binds stop codons to catalyze peptide release. We report two 3.2 Å resolution cryo-EM structures - determined from a single sample - of the 70S ribosome with ArfA•RF2 in the A site. In both states, the ArfA C-terminus occupies the mRNA tunnel downstream of the A site. One state contains a compact inactive RF2 conformation. Ordering of the ArfA N-terminus in the second state rearranges RF2 into an extended conformation that docks the catalytic GGQ motif into the peptidyl-transferase center. Our work thus reveals the structural dynamics of ribosome rescue. The structures demonstrate how ArfA 'senses' the vacant mRNA tunnel and activates RF2 to mediate peptide release without a stop codon, allowing stalled ribosomes to be recycled.