National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01-GM114147
米国
引用
ジャーナル: Nat Struct Mol Biol / 年: 2023 タイトル: A shape-shifting nuclease unravels structured RNA. 著者: Katarina Meze / Armend Axhemi / Dennis R Thomas / Ahmet Doymaz / Leemor Joshua-Tor / 要旨: RNA turnover pathways ensure appropriate gene expression levels by eliminating unwanted transcripts. Dis3-like 2 (Dis3L2) is a 3'-5' exoribonuclease that plays a critical role in human development. ...RNA turnover pathways ensure appropriate gene expression levels by eliminating unwanted transcripts. Dis3-like 2 (Dis3L2) is a 3'-5' exoribonuclease that plays a critical role in human development. Dis3L2 independently degrades structured substrates, including coding and noncoding 3' uridylated RNAs. While the basis for Dis3L2's substrate recognition has been well characterized, the mechanism of structured RNA degradation by this family of enzymes is unknown. We characterized the discrete steps of the degradation cycle by determining cryogenic electron microscopy structures representing snapshots along the RNA turnover pathway and measuring kinetic parameters for RNA processing. We discovered a dramatic conformational change that is triggered by double-stranded RNA (dsRNA), repositioning two cold shock domains by 70 Å. This movement exposes a trihelix linker region, which acts as a wedge to separate the two RNA strands. Furthermore, we show that the trihelix linker is critical for dsRNA, but not single-stranded RNA, degradation. These findings reveal the conformational plasticity of Dis3L2 and detail a mechanism of structured RNA degradation.
chain_id: C, source_name: PDB, initial_model_type: experimental model
詳細
The model of Homo Sapiens Dis3L2 was used as a starting reference for the protein and the nucleic acid was used from PDB 4PMW. All manual building was done in Coot. The hairpin of the RNA was built by using the dsRNA from PDB 5W0O as a template. The nucleotides were mutated to the sequence of hairpinC-U12. To guide the building of the tetraloop, PDB 1F7Y was used to guide the introduction of restraints in the UUCG tetraloop. All model refinements were done in PHENIX.
精密化
空間: REAL / プロトコル: FLEXIBLE FIT
得られたモデル
PDB-8e29: Human Dis3L2 in complex with hairpin C-U12