RAD17 is a protein (large biomolecules, or macromolecules, made up of one or more long chains of amino acid residues) that attaches itself to chromatin before DNA damage and is phosphorylated by ATR after the damage, it also recruits the RAD1-RAD9-HUS1 checkpoint protein complex onto chromatin after DNA damage, which may be required for its phosphorylation.
Cell cycle checkpoint protein RAD17 is a protein that in humans is encoded by the RAD17 gene. Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. This protein binds to chromatin prior to DNA damage and is phosphorylated by ATR after the damage. This protein recruits the RAD1-RAD9-HUS1 checkpoint protein complex onto chromatin after DNA damage, which may be required for its phosphorylation. 
