+Search query
-Structure paper
Title | Mechanism of ribosome rescue by ArfA and RF2. |
---|---|
Journal, issue, pages | Elife, Vol. 6, Year 2017 |
Publish date | Mar 16, 2017 |
Authors | Gabriel Demo / Egor Svidritskiy / Rohini Madireddy / Ruben Diaz-Avalos / Timothy Grant / Nikolaus Grigorieff / Duncan Sousa / Andrei A Korostelev / |
PubMed Abstract | 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 - ...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. |
External links | Elife / PubMed:28300532 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.2 Å |
Structure data | |
Chemicals | ChemComp-MG: ChemComp-ZN: |
Source |
|
Keywords | RIBOSOME / ARFA RF2 ribosome rescue complex |