Peptidyl-tRNA hydrolase is the nascent chain release factor in bacterial ribosome-associated quality control.
Mol Cell
; 84(4): 715-726.e5, 2024 Feb 15.
Article
in En
| MEDLINE
| ID: mdl-38183984
ABSTRACT
Rescuing stalled ribosomes often involves their splitting into subunits. In many bacteria, the resultant large subunits bearing peptidyl-tRNAs are processed by the ribosome-associated quality control (RQC) apparatus that extends the C termini of the incomplete nascent polypeptides with polyalanine tails to facilitate their degradation. Although the tailing mechanism is well established, it is unclear how the nascent polypeptides are cleaved off the tRNAs. We show that peptidyl-tRNA hydrolase (Pth), the known role of which has been to hydrolyze ribosome-free peptidyl-tRNA, acts in concert with RQC factors to release nascent polypeptides from large ribosomal subunits. Dislodging from the ribosomal catalytic center is required for peptidyl-tRNA hydrolysis by Pth. Nascent protein folding may prevent peptidyl-tRNA retraction and interfere with the peptide release. However, oligoalanine tailing makes the peptidyl-tRNA ester bond accessible for Pth-catalyzed hydrolysis. Therefore, the oligoalanine tail serves not only as a degron but also as a facilitator of Pth-catalyzed peptidyl-tRNA hydrolysis.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Peptides
/
Ribosomes
/
Carboxylic Ester Hydrolases
Type of study:
Risk_factors_studies
Language:
En
Journal:
Mol Cell
Year:
2024
Document type:
Article