Summary information and primary citation
- PDB-id
-
3iz4;
DSSR-derived features in text and
JSON formats
- Class
- RNA binding protein-RNA
- Method
- cryo-EM (13.6 Å)
- Summary
- Modified e. coli tmrna in the resume state with the
trna-like domain in the ribosomal p site interacting with
the smpb
- Reference
-
Fu J, Hashem Y, Wower I, Lei J, Liao HY, Zwieb C, Wower
J, Frank J (2010): "Visualizing
the transfer-messenger RNA as the ribosome resumes
translation." Embo J., 29,
3819-3825. doi: 10.1038/emboj.2010.255.
- Abstract
- Bacterial ribosomes stalled by truncated mRNAs are
rescued by transfer-messenger RNA (tmRNA), a dual-function
molecule that contains a tRNA-like domain (TLD) and an
internal open reading frame (ORF). Occupying the empty A
site with its TLD, the tmRNA enters the ribosome with the
help of elongation factor Tu and a protein factor called
small protein B (SmpB), and switches the translation to its
own ORF. In this study, using cryo-electron microscopy, we
obtained the first structure of an in vivo-formed complex
containing ribosome and the tmRNA at the point where the
TLD is accommodated into the ribosomal P site. We show that
tmRNA maintains a stable 'arc and fork' structure on the
ribosome when its TLD moves to the ribosomal P site and
translation resumes on its ORF. Based on the density map,
we built an atomic model, which suggests that SmpB
interacts with the five nucleotides immediately upstream of
the resume codon, thereby determining the correct selection
of the reading frame on the ORF of tmRNA.
