Here the authors used cryogenic electron microscopy and biochemistry to understand how yeast Mcm10 exerts its essential role in DNA replication initiation, finding that it splits the double Cdc45-MCM-GINS-Polε structure. The lagging-strand template is ejected from each MCM ring as the central channel of the helicase becomes too tight to accommodate two DNA strands.
- Sarah S. Henrikus
- Marta H. Gross
- Alessandro Costa