8VS9

Endogenous trans-translation complex with tmRNA*SmpB in the P site and alanyl-tRNA in the A site and deacyl-tRNA in the E site of E. coli 70S ribosome

これはPDB形式変換不可エントリーです。

8VS9 の概要

• エントリーDOI: 10.2210/pdb8vs9/pdb
• EMDBエントリー: 43490
• 分子名称: 16S ribosomal RNA, 50S ribosomal protein L6, Large ribosomal subunit protein bL9, ... (59 entities in total)
• 機能のキーワード: endogenous tmrna, tmrna decoding, a-minor interactions, smpb, cryo-em, alanyl-trna, ribosome
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 59
• 化学式量合計: 2377082.87

構造登録者

Teran, D.,Zhang, Y.,Korostelev, A.A. (登録日: 2024-01-23, 公開日: 2024-05-01)

主引用文献

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

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: 38500588
DOI: 10.3389/fmicb.2024.1369760

実験手法

ELECTRON MICROSCOPY (3.9 Å)