This is a BRCT domain that appears in duplicate in most member sequences. BRCT domains are peptide- and phosphopeptide-binding modules. BRCT domains are present in a number of proteins involved in DNA checkpoint controls and DNA repair [1,2].

1: Microcephalin is a DNA damage response protein involved in regulation of CHK1 and BRCA1. Xu X, Lee J, Stern DF; J Biol Chem. 2004;279:34091-34094. PMID:15220350

2: Cloning and characterization of the rad4 gene of Schizosaccharomyces pombe; a gene showing short regions of sequence similarity to the human XRCC1 gene. Fenech M, Carr AM, Murray J, Watts FZ, Lehmann AR; Nucleic Acids Res. 1991;19:6737-6741. PMID:1762905