10779/crick.11371797.v1 Hazal B Kose Hazal B Kose Nicolai B Larsen Nicolai B Larsen Julien P Duxin Julien P Duxin Hasan Yardimci Hasan Yardimci Dynamics of the eukaryotic replicative helicase at lagging-strand protein barriers support the steric exclusion model The Francis Crick Institute 2019 CMG DNA-protein crosslink eukaryotic DNA replication replicative helicase single-molecule imaging steric exclusion Yardimci FC001221 PC-ack CS-ack SB-ack 0601 Biochemistry and Cell Biology 2019-12-16 17:38:51 Journal contribution https://crick.figshare.com/articles/journal_contribution/Dynamics_of_the_eukaryotic_replicative_helicase_at_lagging-strand_protein_barriers_support_the_steric_exclusion_model/11371797 Progression of DNA replication depends on the ability of the replisome complex to overcome nucleoprotein barriers. During eukaryotic replication, the CMG helicase translocates along the leading-strand template and unwinds the DNA double helix. While proteins bound to the leading-strand template efficiently block the helicase, the impact of lagging-strand protein obstacles on helicase translocation and replisome progression remains controversial. Here, we show that CMG and replisome progressions are impaired when proteins crosslinked to the lagging-strand template enhance the stability of duplex DNA. In contrast, proteins that exclusively interact with the lagging-strand template influence neither the translocation of isolated CMG nor replisome progression in Xenopus egg extracts. Our data imply that CMG completely excludes the lagging-strand template from the helicase central channel while unwinding DNA at the replication fork, which clarifies how two CMG helicases could freely cross one another during replication initiation and termination.