Synergism between CMG helicase and leading strand DNA polymerase at replication fork
Abstract The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-elect...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-09-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-023-41506-0 |
| _version_ | 1797558157310951424 |
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| author | Zhichun Xu Jianrong Feng Daqi Yu Yunjing Huo Xiaohui Ma Wai Hei Lam Zheng Liu Xiang David Li Toyotaka Ishibashi Shangyu Dang Yuanliang Zhai |
| author_facet | Zhichun Xu Jianrong Feng Daqi Yu Yunjing Huo Xiaohui Ma Wai Hei Lam Zheng Liu Xiang David Li Toyotaka Ishibashi Shangyu Dang Yuanliang Zhai |
| author_sort | Zhichun Xu |
| collection | DOAJ |
| description | Abstract The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-electron microscopy structures of a yeast replisome comprising CMG, leading-strand polymerase Polε and three accessory factors on a forked DNA. In these structures, Polε engages or disengages with the motor domains of the CMG by occupying two alternative positions, which closely correlate with the rotational movement of the single-stranded DNA around the MCM pore. During this process, the polymerase remains stably coupled to the helicase using Psf1 as a hinge. This synergism is modulated by a concerted rearrangement of ATPase sites to drive DNA translocation. The Polε-MCM coupling is not only required for CMG formation to initiate DNA replication but also facilitates the leading-strand DNA synthesis mediated by Polε. Our study elucidates a mechanism intrinsic to the replisome that coordinates the activities of CMG and Polε to negotiate any roadblocks, DNA damage, and epigenetic marks encountered during translocation along replication forks. |
| first_indexed | 2024-03-10T17:26:30Z |
| format | Article |
| id | doaj.art-8b0eab14f8004ba38ff7b0abfe5819c5 |
| institution | Directory Open Access Journal |
| issn | 2041-1723 |
| language | English |
| last_indexed | 2024-03-10T17:26:30Z |
| publishDate | 2023-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Nature Communications |
| spelling | doaj.art-8b0eab14f8004ba38ff7b0abfe5819c52023-11-20T10:09:00ZengNature PortfolioNature Communications2041-17232023-09-0114111610.1038/s41467-023-41506-0Synergism between CMG helicase and leading strand DNA polymerase at replication forkZhichun Xu0Jianrong Feng1Daqi Yu2Yunjing Huo3Xiaohui Ma4Wai Hei Lam5Zheng Liu6Xiang David Li7Toyotaka Ishibashi8Shangyu Dang9Yuanliang Zhai10School of Biological Sciences, The University of Hong KongDivision of Life Science, The Hong Kong University of Science & TechnologyDivision of Life Science, The Hong Kong University of Science & TechnologySchool of Biological Sciences, The University of Hong KongDivision of Life Science, The Hong Kong University of Science & TechnologySchool of Biological Sciences, The University of Hong KongDepartment of Chemistry, The University of Hong KongDepartment of Chemistry, The University of Hong KongDivision of Life Science, The Hong Kong University of Science & TechnologyDivision of Life Science, The Hong Kong University of Science & TechnologySchool of Biological Sciences, The University of Hong KongAbstract The replisome that replicates the eukaryotic genome consists of at least three engines: the Cdc45-MCM-GINS (CMG) helicase that separates duplex DNA at the replication fork and two DNA polymerases, one on each strand, that replicate the unwound DNA. Here, we determined a series of cryo-electron microscopy structures of a yeast replisome comprising CMG, leading-strand polymerase Polε and three accessory factors on a forked DNA. In these structures, Polε engages or disengages with the motor domains of the CMG by occupying two alternative positions, which closely correlate with the rotational movement of the single-stranded DNA around the MCM pore. During this process, the polymerase remains stably coupled to the helicase using Psf1 as a hinge. This synergism is modulated by a concerted rearrangement of ATPase sites to drive DNA translocation. The Polε-MCM coupling is not only required for CMG formation to initiate DNA replication but also facilitates the leading-strand DNA synthesis mediated by Polε. Our study elucidates a mechanism intrinsic to the replisome that coordinates the activities of CMG and Polε to negotiate any roadblocks, DNA damage, and epigenetic marks encountered during translocation along replication forks.https://doi.org/10.1038/s41467-023-41506-0 |
| spellingShingle | Zhichun Xu Jianrong Feng Daqi Yu Yunjing Huo Xiaohui Ma Wai Hei Lam Zheng Liu Xiang David Li Toyotaka Ishibashi Shangyu Dang Yuanliang Zhai Synergism between CMG helicase and leading strand DNA polymerase at replication fork Nature Communications |
| title | Synergism between CMG helicase and leading strand DNA polymerase at replication fork |
| title_full | Synergism between CMG helicase and leading strand DNA polymerase at replication fork |
| title_fullStr | Synergism between CMG helicase and leading strand DNA polymerase at replication fork |
| title_full_unstemmed | Synergism between CMG helicase and leading strand DNA polymerase at replication fork |
| title_short | Synergism between CMG helicase and leading strand DNA polymerase at replication fork |
| title_sort | synergism between cmg helicase and leading strand dna polymerase at replication fork |
| url | https://doi.org/10.1038/s41467-023-41506-0 |
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