TopBP1, also termed DNA topoisomerase II-beta-binding protein 1, functions in DNA replication and damage response. It binds double-stranded DNA breaks and nicks as well as single-stranded DNA [1-4]. It consists of multiple copies of BRCT domains, wit ...
TopBP1, also termed DNA topoisomerase II-beta-binding protein 1, functions in DNA replication and damage response. It binds double-stranded DNA breaks and nicks as well as single-stranded DNA [1-4]. It consists of multiple copies of BRCT domains, with a triple tandem BRCT domains at the N-terminal (designated BRCT0, BRCT1 and BRCT2), also observed in ECT2 that may represent a new type of consecutive BRCT domains [1-3]. This entry represents the first BRCT domain (BRCT0) of TopBP1 [1-4]. BRCT1/2 are included in Pfam:PF00533. Although ECT2 and TopBP1 share a similar cylinder-like crystal structure and distribution of secondary structure, some helices exhibit different orientations especially in the BRCT0 domain.