Endogenous trans-translation structure visualizes the decoding of the first tmRNA alanine codon

Ribosomes stall on truncated or otherwise damaged mRNAs. Bacteria rely on ribosome rescue mechanisms to replenish the pool of ribosomes available for translation. Trans-translation, the main ribosome-rescue pathway, uses a circular hybrid transfer-messenger RNA (tmRNA) to restart translation and lab...

Celý popis

Uloženo v:
Podrobná bibliografie
Vydáno v:Frontiers in microbiology Ročník 15; s. 1369760
Hlavní autoři: Teran, David, Zhang, Ying, Korostelev, Andrei A.
Médium: Journal Article
Jazyk:angličtina
Vydáno: Switzerland Frontiers Media S.A 04.03.2024
Témata:
A-minor interactions
alanyl-tRNA
cryo-EM
endogenous tmRNA
Microbiology
SmpB
tmRNA decoding
endogenous tmRNA
alanyl-tRNA
SmpB
cryo-EM
tmRNA decoding
A-minor interactions
ISSN:1664-302X, 1664-302X
On-line přístup:Získat plný text
Tagy: Přidat tag
Žádné tagy, Buďte první, kdo vytvoří štítek k tomuto záznamu!
Popis
Shrnutí:Ribosomes stall on truncated or otherwise damaged mRNAs. Bacteria rely on ribosome rescue mechanisms to replenish the pool of ribosomes available for translation. Trans-translation, the main ribosome-rescue pathway, uses a circular hybrid transfer-messenger RNA (tmRNA) to restart translation and label the resulting peptide for degradation. Previous studies have visualized how tmRNA and its helper protein SmpB interact with the stalled ribosome to establish a new open reading frame. As tmRNA presents the first alanine codon via a non-canonical mRNA path in the ribosome, the incoming alanyl-tRNA must rearrange the tmRNA molecule to read the codon. Here, we describe cryo-EM analyses of an endogenous Escherichia coli ribosome-tmRNA complex with tRNA Ala accommodated in the A site. The flexible adenosine-rich tmRNA linker, which connects the mRNA-like domain with the codon, is stabilized by the minor groove of the canonically positioned anticodon stem of tRNA Ala . This ribosome complex can also accommodate a tRNA near the E (exit) site, bringing insights into the translocation and dissociation of the tRNA that decoded the defective mRNA prior to tmRNA binding. Together, these structures uncover a key step of ribosome rescue, in which the ribosome starts translating the tmRNA reading frame.
Bibliografie:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
Ronghao Chen, The Ohio State University, United States
Present address: Ying Zhang, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
Edited by: Matthieu G. Gagnon, University of Texas Medical Branch at Galveston, United States
Reviewed by: Reynald Gillet, University of Rennes, France
ISSN:1664-302X
1664-302X
DOI:10.3389/fmicb.2024.1369760