The DNA-repair function of the protein produced by a key breast cancer gene, BRCA2, has been unravelled. Researchers say the discoveries should throw new light on the precise causes of hereditary breast and ovarian cancer.

Women with a mutation in the BRCA2 gene are up to seven times more likely to develop breast cancer during their lifetime compared with women with a normal version of the gene.

The team crystallised about a quarter of the giant BRCA2 protein. Next they bombarded the crystals with X-rays and used the resulting diffraction patterns to uncover the three dimensional structure of the protein. Then, they showed that BRCA2 binds to DNA commonly found near broken strands. More here.