Ctf4 organizes sister replisomes and Pol α into a replication factory.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31589141.
- Also identified by DOI 10.7554/eLife.47405 and PMC identifier 6800005.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The current view is that eukaryotic replisomes are independent. Here we show that Ctf4 tightly dimerizes CMG helicase, with an extensive interface involving Psf2, Cdc45, and Sld5. Interestingly, Ctf4 binds only one Pol α-primase. Thus, Ctf4 may have evolved as a trimer to organize two helicases and one Pol α-primase into a replication factory. In the 2CMG-Ctf4<sub>3</sub>-1Pol α-primase factory model, the two CMGs nearly face each other, placing the two lagging strands toward the center and two leading strands out the sides. The single Pol α-primase is centrally located and may prime both sister replisomes. The Ctf4-coupled-sister replisome model is consistent with cellular microscopy studies revealing two sister forks of an origin remain attached and are pushed forward from a protein platform. The replication factory model may facilitate parental nucleosome transfer during replication.
Medical subject headings
- DNA Polymerase I
- DNA Replication
- DNA, Fungal
- DNA-Binding Proteins
- Saccharomyces cerevisiae
- Saccharomyces cerevisiae Proteins