From single-molecule to synchrotron: New tools for investigating the molecular mechanisms of Aicardi-Goutires Syndrome and other aberrant DNA diseases

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This studentship is focused on developing new biophysical tools to understand the molecular basis of aberrant DNA diseases. You will be part of a new, multidisciplinary collaboration between the Sheffield Institute for Nucleic Acids (http://genome.sheffield.ac.uk/) at the University of Sheffield, and Diamond Light Source Ltd (https://www.diamond.ac.uk/Home.html). As such it is likely the project will attract an enhanced stipend (as an iCASE award).A major challenge to genome stability is the presence of small amounts of RNA interspersed within DNA. Recent studies report the levels of ribose incorporation in mammalian genomes to be >1 million nucleotides per day, making it the most frequent source of cellular DNA damage in eukaryotes. This aberrant RNA must be removed from the DNA. The human enzymes responsible for this are RNAseH1 - which recognises runs of at least four ribonucleotides), and RNAseH2 - which can detect a single ribonucleotide, hydrolysing the 5'-phosphodiester bond leading to its removal.RNaseH2 is formed from three polypeptides; RNAse H2A, H2B, and H2C. Single mutations in all these subunits have been found in patients suffering from Aicardi-Goutières Syndrome, an inflammatory disease effecting the brain and skin. Additionally, we recently reported that accumulation of DNA/RNA hybrids cause neurodegeneration in motor neuron disease and frontotemporal dementia (1). The goal of this project is to understand how these crucial enzymes locate ribonucleotides (one additional oxygen atom) within a vast sea of normal DNA and the effects of disease-causing mutations on this process.You will use established single-molecule FRET techniques in the Craggs Lab (2), alongside new Small Angle X-ray Scattering methods (using gold nano-particles) that you will develop in collaboration with beamline scientists at Diamond, both in combination with computational modelling (with our collaborator in Denmark, Prof Kresten Lindorff-Larsen https://www1.bio.ku.dk/english/research/bms/research/sbinlab/groups/kll/), to characterize the conformational dynamics of aberrant nucleic acids in solution, both in the presence and absence of RNaseH proteins.This studentship provides a unique opportunity to be trained across a range of cutting-edge biophysical techniques and apply them to a fundamental question on the molecular understanding of disease. We are looking for creative individuals capable of working across disciplines.