Year: 2019
Type: review
Abstract: A cursory look at any textbook image of DNA replication might suggest that the complex machine that is the replisome runs smoothly along the chromosomal DNA. However, many DNA sequences can adopt non-B form secondary structures and these have the potential to impede progression of the replisome. A picture is emerging in which the maintenance of processive DNA replication requires the action of a significant number of additional proteins beyond the core replisome to resolve secondary structures in the DNA template. By ensuring that DNA synthesis remains closely coupled to DNA unwinding by the replicative helicase, these factors prevent impediments to the replisome from causing genetic and epigenetic instability. This review considers the circumstances in which DNA forms secondary structures, the potential responses of the eukaryotic replisome to these impediments in the light of recent advances in our understanding of its structure and operation and the mechanisms cells deploy to remove secondary structure from the DNA. To illustrate the principles involved, we focus on one of the best understood DNA secondary structures, G quadruplexes (G4s), and on the helicases that promote their resolution.
Source: Genes
Authors: Leticia Koch Lerner, Julian E. Sale
Institution: MRC Laboratory of Molecular Biology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $1,824
Funder: Medical Research Council
Award: G1281656723
OpenAlex ID: W2912285434