The C-terminal residues of Saccharomyces cerevisiae Mec1 are required for its localization, stability, and function.

Mec1, a member of the phosphoinositide three-kinase-related kinase (PIKK) family of proteins, is involved in the response to replicative stress and DNA damage and in telomere maintenance. An essential 30 to 35 residue, the FATC domain is found at the C-terminus of all PIKK family members. To investigate the roles of the C-terminal residues of Mec1, we characterized alleles of Saccharomyces cerevisiae mec1 that alter the FATC domain.