8VSA
Endogenous trans-translation complex with tmRNA*SmpB in the P site and alanyl-tRNA in the A site of E. coli 70S ribosome
This is a non-PDB format compatible entry.
Summary for 8VSA
| Entry DOI | 10.2210/pdb8vsa/pdb |
| EMDB information | 43491 |
| Descriptor | 50S ribosomal protein L2, 50S ribosomal protein L13, 50S ribosomal protein L14, ... (58 entities in total) |
| Functional Keywords | endogenous tmrna, tmrna decoding, a-minor interactions, smpb, cryo-em, alanyl-trna, ribosome |
| Biological source | Escherichia coli More |
| Total number of polymer chains | 58 |
| Total formula weight | 2352280.08 |
| Authors | |
| Primary citation | Teran, D.,Zhang, Y.,Korostelev, A.A. Endogenous trans-translation structure visualizes the decoding of the first tmRNA alanine codon. Front Microbiol, 15:1369760-1369760, 2024 Cited by PubMed Abstract: 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 ribosome-tmRNA complex with tRNA 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. 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. PubMed: 38500588DOI: 10.3389/fmicb.2024.1369760 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.7 Å) |
Structure validation
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