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-Structure paper
タイトル | Structural and dynamic basis of DNA capture and translocation by mitochondrial Twinkle helicase. |
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ジャーナル・号・ページ | Nucleic Acids Res, Vol. 50, Issue 20, Page 11965-11978, Year 2022 |
掲載日 | 2022年11月11日 |
著者 | Zhuo Li / Parminder Kaur / Chen-Yu Lo / Neil Chopra / Jamie Smith / Hong Wang / Yang Gao / |
PubMed 要旨 | Twinkle is a mitochondrial replicative helicase which can self-load onto and unwind mitochondrial DNA. Nearly 60 mutations on Twinkle have been linked to human mitochondrial diseases. Using cryo- ...Twinkle is a mitochondrial replicative helicase which can self-load onto and unwind mitochondrial DNA. Nearly 60 mutations on Twinkle have been linked to human mitochondrial diseases. Using cryo-electron microscopy (cryo-EM) and high-speed atomic force microscopy (HS-AFM), we obtained the atomic-resolution structure of a vertebrate Twinkle homolog with DNA and captured in real-time how Twinkle is self-loaded onto DNA. Our data highlight the important role of the non-catalytic N-terminal domain of Twinkle. The N-terminal domain directly contacts the C-terminal helicase domain, and the contact interface is a hotspot for disease-related mutations. Mutations at the interface destabilize Twinkle hexamer and reduce helicase activity. With HS-AFM, we observed that a highly dynamic Twinkle domain, which is likely to be the N-terminal domain, can protrude ∼5 nm to transiently capture nearby DNA and initialize Twinkle loading onto DNA. Moreover, structural analysis and subunit doping experiments suggest that Twinkle hydrolyzes ATP stochastically, which is distinct from related helicases from bacteriophages. |
リンク | Nucleic Acids Res / PubMed:36400570 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.51 - 8.5 Å |
構造データ | EMDB-27842, PDB-8e2l: EMDB-27843: Structure of Lates calcarifer Twinkle helicase with ATP and DNA, conformer 2 EMDB-27844: Structure of Lates calcarifer Twinkle helicase, apo hexamer EMDB-27845: Structure of Lates calcarifer Twinkle helicase, apo heptamer |
化合物 | ChemComp-ATP: ChemComp-MG: |
由来 |
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キーワード | REPLICATION/DNA / Helicase Mitochondrion / REPLICATION-DNA complex |