摘要：SummaryThe central step in the initiation of eukaryotic DNA replication is the loading of the minichromosome maintenance 2–7 (MCM2-7) complex, the core of the replicative DNA helicase, onto chromatin at replication origin. Here, we reported the cryo-EM structure of endogenous human single hexameric MCM2-7 complex with a resolution at 4.4 Å, typically an open-ring hexamer with a gap between Mcm2 and Mcm5. Strikingly, further analysis revealed that human MCM2-7 can self-associate to form a loose double hexamer which potentially implies a novel mechanism underlying the MCM2-7 loading in eukaryote. The high-resolution cryo-EM structure of human MCM2-7 is critical for understanding the molecular mechanisms governing human DNA replication, especially the MCM2-7 chromatin loading and pre-replicative complex assembly.Graphical abstractDisplay OmittedHighlights•A Twin-Strep-Tag II tag was fused to Mcm4 by using CRISPR-Cas9 technique•The endogenous human MCM2-7 complex was successfully purified•The high-resolution cryo-EM structure of human hexameric MCM2-7 complex•The human single MCM2-7 hexamer can self-associate to form a double hexamerMolecular biology; Cell biology; Structural biology
