دورية أكاديمية
Structural and mechanistic insights into the MCM8/9 helicase complex
| العنوان: | Structural and mechanistic insights into the MCM8/9 helicase complex |
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| المؤلفون: | Zhuangfeng Weng, Jiefu Zheng, Yiyi Zhou, Zuer Lu, Yixi Wu, Dongyi Xu, Huanhuan Li, Huanhuan Liang, Yingfang Liu |
| المصدر: | eLife, Vol 12 (2023) |
| بيانات النشر: | eLife Sciences Publications Ltd, 2023. |
| سنة النشر: | 2023 |
| المجموعة: | LCC:Medicine LCC:Science LCC:Biology (General) |
| مصطلحات موضوعية: | MCM8/9, helicase, homologous recombination, HROB, cryo-electron microscopy, DNA unwinding, Medicine, Science, Biology (General), QH301-705.5 |
| الوصف: | MCM8 and MCM9 form a functional helicase complex (MCM8/9) that plays an essential role in DNA homologous recombination repair for DNA double-strand break. However, the structural characterization of MCM8/9 for DNA binding/unwinding remains unclear. Here, we report structures of the MCM8/9 complex using cryo-electron microscopy single particle analysis. The structures reveal that MCM8/9 is arranged into a heterohexamer through a threefold symmetry axis, creating a central channel that accommodates DNA. Multiple characteristic hairpins from the N-terminal oligosaccharide/oligonucleotide (OB) domains of MCM8/9 protrude into the central channel and serve to unwind the duplex DNA. When activated by HROB, the structure of MCM8/9’s N-tier ring converts its symmetry from C3 to C1 with a conformational change that expands the MCM8/9’s trimer interface. Moreover, our structural dynamic analyses revealed that the flexible C-tier ring exhibited rotary motions relative to the N-tier ring, which is required for the unwinding ability of MCM8/9. In summary, our structural and biochemistry study provides a basis for understanding the DNA unwinding mechanism of MCM8/9 helicase in homologous recombination. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 2050-084X |
| Relation: | https://elifesciences.org/articles/87468; https://doaj.org/toc/2050-084X |
| DOI: | 10.7554/eLife.87468 |
| URL الوصول: | https://doaj.org/article/9873603dbe2f4f9d8fd2613fafaae878 |
| رقم الأكسشن: | edsdoj.9873603dbe2f4f9d8fd2613fafaae878 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 2050084X |
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| DOI: | 10.7554/eLife.87468 |