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-Structure paper
タイトル | High-resolution structure of the presynaptic RAD51 filament on single-stranded DNA by electron cryo-microscopy. |
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ジャーナル・号・ページ | Nucleic Acids Res, Vol. 44, Issue 19, Page 9017-9030, Year 2016 |
掲載日 | 2016年11月2日 |
著者 | Judith M Short / Yang Liu / Shaoxia Chen / Neelesh Soni / Mallur S Madhusudhan / Mahmud K K Shivji / Ashok R Venkitaraman / |
PubMed 要旨 | Homologous DNA recombination (HR) by the RAD51 recombinase enables error-free DNA break repair. To execute HR, RAD51 first forms a presynaptic filament on single-stranded (ss) DNA, which catalyses ...Homologous DNA recombination (HR) by the RAD51 recombinase enables error-free DNA break repair. To execute HR, RAD51 first forms a presynaptic filament on single-stranded (ss) DNA, which catalyses pairing with homologous double-stranded (ds) DNA. Here, we report a structure for the presynaptic human RAD51 filament at 3.5-5.0Å resolution using electron cryo-microscopy. RAD51 encases ssDNA in a helical filament of 103Å pitch, comprising 6.4 protomers per turn, with a rise of 16.1Å and a twist of 56.2°. Inter-protomer distance correlates with rotation of an α-helical region in the core catalytic domain that is juxtaposed to ssDNA, suggesting how the RAD51-DNA interaction modulates protomer spacing and filament pitch. We map Fanconi anaemia-like disease-associated RAD51 mutations, clarifying potential phenotypes. We predict binding sites on the presynaptic filament for two modules present in each BRC repeat of the BRCA2 tumour suppressor, a critical HR mediator. Structural modelling suggests that changes in filament pitch mask or expose one binding site with filament-inhibitory potential, rationalizing the paradoxical ability of the BRC repeats to either stabilize or inhibit filament formation at different steps during HR. Collectively, our findings provide fresh insight into the structural mechanism of HR and its dysregulation in human disease. |
リンク | Nucleic Acids Res / PubMed:27596592 / PubMed Central |
手法 | EM (らせん対称) |
解像度 | 4.2 Å |
構造データ | |
化合物 | ChemComp-ANP: |
由来 |
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キーワード | DNA BINDING PROTEIN (DNA結合タンパク質) / cryoEM DNA repair recombinase / CELL CYCLE (細胞周期) / RECOMBINATION (遺伝的組換え) / recombinase / cryoEM (低温電子顕微鏡法) / Human Rad51 (Rad51) / single-stranded DNA (デオキシリボ核酸) |