There are various types of damage to DNA, and DNA strand breaks are one of them, involving a cut in one or both DNA strands. Double-strand breaks in cellular DNA are especially dangerous and can trigger tumorigenesis, the process involved in the production of a new tumor or tumors.

Researchers from The Ludwig Maximilian University of Munich (LMU) have now determined the structure of a protein involved in the repair and signaling of DNA double-strand breaks. The work throws new light on the origins of neurodegenerative diseases and certain tumor types.

Agents such as radiation or environmental toxins can cause double-stranded breaks in genomic DNA, which facilitate the development of tumors or the neurodegenerative disorders ataxia telangiectasia (AT) and AT-like disease (ATLD). Hence efficient repair mechanisms are essential for cell survival and function. The so-called MRN complex is an important component of one such system, and its structure has just been elucidated by a team led by Professor Karl-Peter Hopfner of LMU's Gene Center.