National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
米国
引用
ジャーナル: Proc Natl Acad Sci U S A / 年: 2025 タイトル: Structural switching dynamically controls the doubly pseudoknotted Rous sarcoma virus-programmed ribosomal frameshifting element. 著者: Christopher P Jones / Adrian R Ferré-D'Amaré / 要旨: A hallmark of retrovirus replication is the translation of two different polyproteins from one RNA through programmed -1 frameshifting. This is a mechanism in which the actively translating ribosome ...A hallmark of retrovirus replication is the translation of two different polyproteins from one RNA through programmed -1 frameshifting. This is a mechanism in which the actively translating ribosome is induced to slip in the 5' direction at a defined codon and then continues translating in the new reading frame. Programmed frameshifting controls the stoichiometry of viral proteins and is therefore under stringent evolutionary selection. Forty years ago, the first frameshifting stimulatory element was discovered in the Rous sarcoma virus. The ~120 nt RNA segment was predicted to contain a pseudoknot, but its 3D structure has remained elusive. Now, we have determined cryoEM and X-ray crystallographic structures of this classic retroviral element, finding that it adopts a butterfly-like double-pseudoknot fold. One "wing" contains a dynamic pyrimidine-rich helix, observed crystallographically in two conformations and in a third conformation via cryoEM. The other wing encompasses the predicted pseudoknot, which interacts with a second unexpected pseudoknot through a toggle residue, A2546. This key purine switches conformations between structural states and tunes the stability of interacting residues in the two wings. We find that its mutation can modulate frameshifting by as much as 50-fold, likely by altering the relative abundance of different structural states in the conformational ensemble of the RNA. Taken together, our structure-function analyses reveal how a dynamic double pseudoknot junction stimulates frameshifting by taking advantage of conformational heterogeneity, supporting a multistate model in which high Shannon entropy enhances frameshifting efficiency.
根拠: gel filtration, Dimerized in folded RNA solution in an ~1:5 ratio of dimer:monomer
タイプ
名称
対称操作
数
identity operation
1_555
x,y,z
1
Buried area
8130 Å2
ΔGint
-46 kcal/mol
Surface area
33720 Å2
単位格子
Length a, b, c (Å)
43.763, 68.246, 209.563
Angle α, β, γ (deg.)
90.00, 90.00, 90.00
Int Tables number
19
Space group name H-M
P212121
-
要素
#1: RNA鎖
frameshiftingpseudoknotRNA
分子量: 35680.164 Da / 分子数: 2 / 由来タイプ: 組換発現 詳細: Purified from in vitro transcription via gel electrophoresis and elution then refolded (see doi: 10.15252/embj.201489209 for general RNA prep details) 由来: (組換発現) Rous sarcoma virus - Prague C (ラウス肉腫ウイルス) 発現宿主: in vitro transcription vector pT7-TP(deltai) (その他) 参照: GenBank: 210171