Mechanism of DNA unwinding by MCM8-9 in complex with HROB

Acharya, Ananya; Bret, Hélène; Huang, Jen-Wei; Mütze; Martin; Göse, Martin; Kissling, Vera Maria; Seidel; Ralf; Ciccia, Alberto; Guérois, Raphaël; Cejka, Petr

doi:10.1038/s41467-024-47936-8

Back

Journal article

Mechanism of DNA unwinding by MCM8-9 in complex with HROB

Acharya, Ananya ORCID Institute for Research in Biomedicine (IRB), Faculty of Biomedical Sciences, Università della Svizzera italiana, Switzerland ; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
Bret, Hélène Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
Huang, Jen-Wei Department of Genetics and Development, Institute for Cancer Genetics, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
Mütze; Martin Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
Göse, Martin Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
Kissling, Vera Maria Particles-Biology Interactions Laboratory, Department of Materials Meet Life, Swiss Federal Laboratories for Materials Science and Technology (Empa), St. Gallen, Switzerland ; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
Seidel; Ralf Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
Ciccia, Alberto Department of Genetics and Development, Institute for Cancer Genetics, Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA
Guérois, Raphaël Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
Cejka, Petr ORCID Institute for Research in Biomedicine (IRB), Faculty of Biomedical Sciences, Università della Svizzera italiana, Switzerland ; Department of Biology, Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland

2024

Published in:

Nature communications. - 2024, vol. 15, p. 3584

English HROB promotes the MCM8-9 helicase in DNA damage response. To understand how HROB activates MCM8-9, we defined their interaction interface. We showed that HROB makes important yet transient contacts with both MCM8 and MCM9, and binds the MCM8-9 heterodimer with the highest affinity. MCM8-9-HROB prefer branched DNA structures, and display low DNA unwinding processivity. MCM8-9 unwinds DNA as a hexamer that assembles from dimers on DNA in the presence of ATP. The hexamer involves two repeating protein-protein interfaces between the alternating MCM8 and MCM9 subunits. One of these interfaces is quite stable and forms an obligate heterodimer across which HROB binds. The other interface is labile and mediates hexamer assembly, independently of HROB. The ATPase site formed at the labile interface contributes disproportionally more to DNA unwinding than that at the stable interface. Here, we show that HROB promotes DNA unwinding downstream of MCM8-9 loading and ring formation on ssDNA.

Collections