Large multi-protein complexes perform many essential functions in eukaryotic cells. My group purifies, assays and determines structures of these macromolecular machines to understand their mechanisms. This often involves a combination of several techniques or the development new methods.
This PhD project will address DNA repair mechanisms, specifically the cellular response to DNA crosslinks and replication stress. The Fanconi Anaemia (FA) pathway is at the centre of DNA crosslink repair and involves a large multiprotein E3 ubiquitin ligase (the FA core complex) and the FANCD2-FANCI heterodimer. Deregulation of this pathway can lead to human disease. We aim to understand the molecular mechanisms of crosslink repair at stalled replication forks. Recent work from my group using biochemical reconstitution, single molecule imaging and cryo-EM has shown that FANCD2-FANCI forms a DNA clamp that diffuses on double-stranded DNA. By sliding along the DNA, FANCD2-FANCI monitors its integrity and stalls when it reaches a single-stranded gap. This identifies and protects the DNA lesion, and promotes recruitment of downstream repair factors. This project will involve reconstitution of protein-DNA assemblies, identification of protein interactions and determination of structures using cryoEM.
Please contact me for more information and to discuss projects.