We have recently discovered a novel mechanism for repair of alkylation damage in DNA, performed by the E.coli AlkB protein, and also by human AlkB homologues. This repair function involves the demethylation of 1-methyladenine and 3-methylcytosine lesions discoveries have opened up many interesting possibilities for further studies. The project will involve characterisation of AlkB-like proteins of unknown function and searches for alternative substrates for AlkB proteins. The biological significan ce o f the RNA repair activity of these enzymes will also be investigated. Furthermore, collaborations have been initiated to elucidate the threedimensional structure of the AlkB proteins, and to study the consequences of genetically ablating different AlkB p roteins in a mous model (knock-out mice). The project will be performed in an environment where several strong research groups are focusing their efforts on various aspects of DNA repair.