The BRCA1 C-terminal (BRCT) domain is a modular unit of ~100 amino acids that folds independently and recognizes linear phosphoserine or phosphothreonine regions to mediate protein-protein and protein-DNA interactions. BRCT domains were initially recognized in the C-terminal region of the breast cancer protein BRCA1, as well as the p53 binding protein (53BP1; TP53BP1), and the yeast cell cycle checkpoint protein RAD9. BRCT domains often occur as tandem repeats at the C-terminal end of several proteins that are functionally diverse. Most BRCT domain-containing proteins participate in DNA-damage checkpoint control or DNA-repair pathways, or both. Thus, BRCT domain-containing proteins likely participate in the cellular response to DNA damage.Germ-line mutations of the tumor suppressor genes BRCA1 and BRCA2 pre-dispose women to familial breast and ovarian cancer and are associated with approximately 10% of the cases. The carboxy-terminal BRCT domain in BRCA1 is involved in DNA repair and transcriptional activation. The BRCT region of BRCA1 binds phosphorylated BACH1, a DEAH helicase, which is essential for mediating repair of DNA double-strand breaks by controlling G2 to M phase transition during cell cycle progression. BRCA1 also contains an N-terminal protein-protein-interaction RING-finger domain, that partners with BRCA1-associated RING domain 1 (BARD1). The BRCA1/BARD1 heterodimer maintains genomic stability by regulating DNA damage repair and ubiquitination. This product contains the BRCT domains of BRCA1.
