so it is possible that the phosphorylation sites are located on this domain. The same mutant was also not able to phosphorylate Rad53 downstream. The structure of the protein is complex, as it is the site of functional domains and protein interactions. Generally, the protein is composed of 391 amino acids and can be divided into 2 sub sections: the N-terminus and the C-terminus. The N-terminal has 2 Proliferating Cell Nuclear Antigen (PCNA)-like domains that serve as important binding sites to Rad-1 and Hus-1 to formulate the 9-1-1 complex. Also located in the N-terminal, the BH3 motif is crucial for binding to Bcl-2 family proteins in the mitochondria to induce apoptosis. Finally, 3-5’ exonuclease activity that is vital for DNA repair. Meanwhile, The C-terminal has proline rich site, Nuclear Localization Signal(NLS), and a tail. All these regions serve as important binding sites to different components of the DNA damage response, especially the NLS, which has serine and threonine phosphorylation sites. References Further reading