Functional and structural biology studies of DNA repair proteins from the radiation resistant bacterium Deinococcus radiodurans

DNA repair enzymes are important for maintaining genome stability of microorganisms during environmental stress. This project aims to identify the role of DNA repair enzymes in the radiation resistance mechanism of Deinococcus radiodurans (DEIRA) using a combination of molecular biology, biophysical techniques and synchrotron radiation experiments. The DNA glycosylases, 3-methyladenine DNA glycosylase (AlkA) and Endonuclease III (EndoIII), which are present in several copies in the genome of DEIRA, have b een selected as targets for this study. Proteins will be produced recombinantly in quantities necessary for interaction and structural studies. Protein complexes will be characterised through biophysical methods and structural studies will be carried out on stable complexes using Small Angle X-ray Scattering (SAXS) experiments and X-ray crystallography. In addition expression profiling experiments will be carried out to investigate the effect of X-ray irradiation on production of AlkA and EndoIII at RNA a nd protein levels. The project will benefit immensely from the long-standing collaboration investigating mechanisms of DNA repair between the Norwegian Structural Biology centre (NorStruct) at the University of Tromsø and the Macromolecular Crystallograph y (MX) group at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. NorStructs excellent infrastructure will provide a solid basis for this project, which can only be enhanced by the support and access to the state-of-the-art structura l biology facilities available at ESRF.