7ACJ

Structure of translocated trans-translation complex on E. coli stalled ribosome.

This is a non-PDB format compatible entry.

Summary for 7ACJ

• Entry DOI: 10.2210/pdb7acj/pdb
• EMDB information: 11717
• Descriptor: 23S ribosomal RNA, 50S ribosomal protein L5, 50S ribosomal protein L6, ... (57 entities in total)
• Functional Keywords: trans-translation, tmrna, smpb, ribosome, translation
• Biological source: Escherichia coli BL21(DE3); More
• Total number of polymer chains: 55
• Total formula weight: 2256831.39

Authors

Guyomar, C.,D'Urso, G.,Chat, S.,Giudice, E.,Gillet, R. (deposition date: 2020-09-11, release date: 2021-08-18, Last modification date: 2024-04-24)

Primary citation

Guyomar, C.,D'Urso, G.,Chat, S.,Giudice, E.,Gillet, R.
Structures of tmRNA and SmpB as they transit through the ribosome.
Nat Commun, 12:4909-4909, 2021

PubMed Abstract: In bacteria, trans-translation is the main rescue system, freeing ribosomes stalled on defective messenger RNAs. This mechanism is driven by small protein B (SmpB) and transfer-messenger RNA (tmRNA), a hybrid RNA known to have both a tRNA-like and an mRNA-like domain. Here we present four cryo-EM structures of the ribosome during trans-translation at resolutions from 3.0 to 3.4 Å. These include the high-resolution structure of the whole pre-accommodated state, as well as structures of the accommodated state, the translocated state, and a translocation intermediate. Together, they shed light on the movements of the tmRNA-SmpB complex in the ribosome, from its delivery by the elongation factor EF-Tu to its passage through the ribosomal A and P sites after the opening of the B1 bridges. Additionally, we describe the interactions between the tmRNA-SmpB complex and the ribosome. These explain why the process does not interfere with canonical translation.

PubMed: 34389707
DOI: 10.1038/s41467-021-24881-4

Experimental method

ELECTRON MICROSCOPY (3.2 Å)