During S-phase, DNA replication begins at replication origins, where recruited helicase unwinds a portion of the DNA helix. This allows DNA polymerase (along with other enzymes of replication) access to parent DNA templates, in order to synthesise daughter strands. The unwound portion of DNA forms a loop, flanked by Y-shaped ‘forks’ where DNA remains helical.
LiHong W et al. Mechanism of chromosomal DNA replication initiation and replication fork stabilisation in eukaryotes. Sci China Life Sci 2014; 57(5).Springer.
Cvetic C and Walter JC. Eukaryotic origins of DNA replication: could you please be more specific? Seminars in Cell & Developmental Biology 2005; 16.« Back to Glossary Index