Format

Send to

Choose Destination
Sci Adv. 2017 Jun 7;3(6):e1700147. doi: 10.1126/sciadv.1700147. eCollection 2017 Jun.

Ribosome rearrangements at the onset of translational bypassing.

Author information

1
Structural Biology Unit, CIC bioGUNE, 48160 Derio, Spain.
2
Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.

Abstract

Bypassing is a recoding event that leads to the translation of two distal open reading frames into a single polypeptide chain. We present the structure of a translating ribosome stalled at the bypassing take-off site of gene 60 of bacteriophage T4. The nascent peptide in the exit tunnel anchors the P-site peptidyl-tRNAGly to the ribosome and locks an inactive conformation of the peptidyl transferase center (PTC). The mRNA forms a short dynamic hairpin in the decoding site. The ribosomal subunits adopt a rolling conformation in which the rotation of the small subunit around its long axis causes the opening of the A-site region. Together, PTC conformation and mRNA structure safeguard against premature termination and read-through of the stop codon and reconfigure the ribosome to a state poised for take-off and sliding along the noncoding mRNA gap.

KEYWORDS:

bypassing; recoding; ribosome; structure; translation

PMID:
28630923
PMCID:
PMC5462505
DOI:
10.1126/sciadv.1700147
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for PubMed Central
Loading ...
Support Center