TP53BP2 encodes a member of the ASPP (apoptosis-stimulating protein of p53) family of p53 interacting proteins. The protein contains four ankyrin repeats and an SH3 domain involved in protein-protein interactions. It is localized to the perinuclear region of the cytoplasm, and regulates apoptosis and cell growth through interactions with other regulatory molecules including members of the p53 family. Multiple transcript variants encoding different isoforms have been found for this gene.

Sequence analysis determined that BBP is identical to TP53BP2. Binding analysis showed that the ankyrin repeats and SH3 domain of TP53BP2 are required for interaction with both p53 and BCL2 and that TP53BP2 cannot bind to both proteins simultaneously.