Skip to main content
. Author manuscript; available in PMC: 2018 Oct 6.
Published in final edited form as: Annu Rev Cell Dev Biol. 2017 Aug 11;33:291–318. doi: 10.1146/annurev-cellbio-100616-060447

Figure 7. Overview of replication-coupled nucleosome assembly.

Figure 7

The MCM2-7 helicase sits at the foremost edge of the replication fork where its primary function is to unwind non-replicated DNA. Torsional strain ahead of the fork begins to break apart nucleosomes, which must then be recycled to newly synthesized DNA on the other side of the fork. The MCM2 protein can bind (H3–H4)2 tetramers dissociated in the wake of the advancing fork to allow for their subsequent deposition on nascent DNA. Due to its ability to bind (H3–H4)2 tetramers, CAF-1 may help coordinate the deposition of preexisting histones after fork passage. CAF-1 is recruited to the edge of the advancing fork by PCNA, which also serves as a processivity factor for the replicative polymerases ε and δ. CAF-1 then coordinates new H3–H4 deposition onto nascent DNA. The subsequent incorporation of two (H2A-H2B) dimers reforms the nucleosome structure and signifies the end of the process of replication coupled histone deposition.