+検索条件
-Structure paper
| タイトル | Biochemical and structural basis of Dicer helicase function unveiled by resurrecting ancient proteins. |
|---|---|
| ジャーナル・号・ページ | Proc Natl Acad Sci U S A, Vol. 122, Issue 22, Page e2500825122, Year 2025 |
| 掲載日 | 2025年6月3日 |
著者 | Adedeji M Aderounmu / Josephine Maus-Conn / Claudia D Consalvo / Peter S Shen / Brenda L Bass / ![]() |
| PubMed 要旨 | A fully functional Dicer helicase, present in the modern arthropod, uses energy from ATP hydrolysis to power translocation on bound dsRNA, enabling the processive dsRNA cleavage required for ...A fully functional Dicer helicase, present in the modern arthropod, uses energy from ATP hydrolysis to power translocation on bound dsRNA, enabling the processive dsRNA cleavage required for efficient antiviral defense. However, modern Dicer orthologs exhibit divergent helicase functions that affect their ability to contribute to antiviral defense. Moreover, mechanisms that couple ATP hydrolysis to Dicer helicase movement on dsRNA remain enigmatic. We used biochemical and structural analyses of ancestrally reconstructed Dicer helicases to map evolution of dsRNA binding affinity, ATP hydrolysis and translocation. Loss of affinity for dsRNA occurred early in Dicer evolution, coinciding with a decline in translocation activity, despite preservation of ATP hydrolysis activity. Ancestral nematode Dicer also exhibited significant decline in ATP hydrolysis and translocation, but studies of antiviral activities in the modern nematode indicate Dicer retained a role in antiviral defense by recruiting a second helicase. Cryogenic electron microscopy (cryo-EM) analyses of an ancient metazoan Dicer allowed capture of multiple helicase states revealing the mechanism that connects each step of ATP hydrolysis to unidirectional movement along dsRNA. Our study rationalizes the diversity in modern Dicer helicases by connecting ancestral functions to observations in extant enzymes. |
リンク | Proc Natl Acad Sci U S A / PubMed:40434637 / PubMed Central |
| 手法 | EM (単粒子) |
| 解像度 | 3.0 - 3.4 Å |
| 構造データ | EMDB-48678, PDB-9mw6: EMDB-48691, PDB-9mw7: EMDB-48697, PDB-9mw8: EMDB-48708, PDB-9mx3: EMDB-48710, PDB-9mx5: |
| 化合物 | ![]() ChemComp-AF3: ![]() ChemComp-ADP: ![]() ChemComp-MG: |
| 由来 |
|
キーワード | ANTIVIRAL PROTEIN/RNA / RNA helicase / dsRBM / ANTIVIRAL PROTEIN-RNA complex |
ムービー
コントローラー
構造ビューア
万見文献について



著者
リンク












キーワード