DNA Replication

Duplication of the genome is an extraordinarily complex process, involving a large number of enzymes and an intricate regulatory network to promote faithful DNA replication. Errors during DNA replication have far reaching consequences and are responsible for several diseases, most notably cancer. The complexity of the DNA replication machinery means that only now we are beginning to understand how individual proteins promote replisome assembly, DNA replication, and DNA repair.

Our goal is to understand the mechanisms that promote accurate DNA replication, as this represents the basis for genomic stability and life itself. One key event in DNA replication is when the ring shaped replicative helicase encircles DNA, an essential prerequisite to feed single-stranded DNA into polymerases during DNA synthesis, DNA repair, or DNA recombination. Here, we want to elucidate how the helicase engages with DNA. The Speck lab has recently developed a method to block DNA entry and exit into the helicase using a chemical genetics approach (Samel et al G&D 2014). The purposes of this PhD is to generate an advanced light-regulated system (Kawano et al Nature Commun 2015), which allows us to have full control over the DNA insertion/extrusion process. After establishing this in the lab, the successful student will use this technique to investigate how the replication fork is used to guarantee genome stability. The DNA replication group employs Saccharomyces cerevisiae, which is the most used model organism to study DNA replication, as replication factors are well conserved between yeast and humans. The design of the photo-switch will employ de novo structure prediction and structured guided protein engineering techniques and is supported by the recent cryo-electron microscopy insights of the group (Yuan et al Nature Struc Mol Biol 2017). Importantly, the student will address in the Gil laboratory, whether the developed system can be applied in the human context and whether closing the gate specifically harms cancer cells (Woodward et al J Cell Biol 2006). Altogether, this high-profile project will offer the candidate significant training opportunities, a stimulating research environment and deep insights into DNA replication, genome stability, and cancer.