Saccharomyces cerevisiae Cmr1 is a novel damaged-DNA binding protein

초록

Eukaryotic ells have evolved complex mechanisms to maintain genome integrity. Although these mechanisms have been studied extensively, a large number of proteins involved in these pathways remain still to be identified. In this study, in order to identify novel proteins involved in DNA metabolism, we isolated DNA-binding proteins from the crude extract of Saccharomyces cerevisiae using an ssDNA-cellulose column. Along with many well characterized DNA-binding or chromatin associated proteins, Cmr1 protein was isolated repeatedly through four independent experiments. Purified recombinant Cmr1 protein bound to various forms of DNA including double-stranded, single-stranded, and branched DNA. In addition, the DNA-binding activity of Cmr1 showed preference for UV-damaged DNA substrates. In the cell fractionation experiments, Cmr1 protein was found to be present both in the soluble and chromatin fractions, indicating that Cmr1 is a novel chromatin-associated protein, which may involves in a DNA-damage response.