He, Q.Baranovskiy, A.G.Morstadt, L.M.Lisova, A.E.Babayeva, N.D.Lusk, B.L.Lim, C.J.Tahirov, T.H.2025-05-282025-05-282023Nature Structural & Molecular Biology, 2023; 30(5):579-5831545-99931545-9985https://hdl.handle.net/2440/144767The synthesis of RNA–DNA primer by primosome requires coordination between primase and DNA polymerase α subunits, which is accompanied by unknown architectural rearrangements of multiple domains. Using cryogenic electron microscopy, we solved a 3.6 Å human primosome structure caught at an early stage of RNA primer elongation with deoxynucleotides. The structure confirms a long-standing role of primase large subunit and reveals new insights into how primosome is limited to synthesizing short RNA–DNA primers.enCopyright © 2023, The Author(s), under exclusive licence to Springer Nature America, Inc.Cryoelectron microscopy; DNA synthesis; Enzyme mechanisms.HumansDNA PrimaseDNARNADNA PrimersDNA ReplicationJournal article10.1038/s41594-023-00971-3693300Lisova, A.E. [0000-0002-3647-6460]