6SGC

Rabbit 80S ribosome stalled on a poly(A) tail

これはPDB形式変換不可エントリーです。

6SGC の概要

• エントリーDOI: 10.2210/pdb6sgc/pdb
• EMDBエントリー: 10181
• 分子名称: 18S ribosomal RNA, 40S ribosomal protein S8, Ribosomal protein S9 (Predicted), ... (88 entities in total)
• 機能のキーワード: protein translation, ribosome stalling, polya tail, ribosome
• 由来する生物種: Homo sapiens; 詳細
• タンパク質・核酸の鎖数: 86
• 化学式量合計: 3468047.78

構造登録者

Chandrasekaran, V.,Juszkiewicz, S.,Choi, J.,Puglisi, J.D.,Brown, A.,Shao, S.,Ramakrishnan, V.,Hegde, R.S. (登録日: 2019-08-03, 公開日: 2019-12-04, 最終更新日: 2025-10-01)

主引用文献

Chandrasekaran, V.,Juszkiewicz, S.,Choi, J.,Puglisi, J.D.,Brown, A.,Shao, S.,Ramakrishnan, V.,Hegde, R.S.
Mechanism of ribosome stalling during translation of a poly(A) tail.
Nat.Struct.Mol.Biol., 26:1132-1140, 2019

PubMed Abstract: Faulty or damaged messenger RNAs are detected by the cell when translating ribosomes stall during elongation and trigger pathways of mRNA decay, nascent protein degradation and ribosome recycling. The most common mRNA defect in eukaryotes is probably inappropriate polyadenylation at near-cognate sites within the coding region. How ribosomes stall selectively when they encounter poly(A) is unclear. Here, we use biochemical and structural approaches in mammalian systems to show that poly-lysine, encoded by poly(A), favors a peptidyl-transfer RNA conformation suboptimal for peptide bond formation. This conformation partially slows elongation, permitting poly(A) mRNA in the ribosome's decoding center to adopt a ribosomal RNA-stabilized single-stranded helix. The reconfigured decoding center clashes with incoming aminoacyl-tRNA, thereby precluding elongation. Thus, coincidence detection of poly-lysine in the exit tunnel and poly(A) in the decoding center allows ribosomes to detect aberrant mRNAs selectively, stall elongation and trigger downstream quality control pathways essential for cellular homeostasis.

PubMed: 31768042
DOI: 10.1038/s41594-019-0331-x

実験手法

ELECTRON MICROSCOPY (2.8 Å)