ABRAXAS Interacting Region (AIR) of Receptor-Associated Protein 80 (RAP80), and related domains
RAP80 and ABRAXAS are integral subunits of the BRCA1-A complex which also contains MERIT40 (Mediator of Rap80 Interactions and Targeting 40 kD, also known as BABAM1), BRE (also known as BABAM2, BRCC45 and BRCC4), and BRCC36 (also known as BRCC3). BRCA1-A functions in DNA double-strand break (DSB) repair. RAP80 interacts with the ABRAXAS, MERIT40, and BRE subunits. It is the interaction with ABRAXAS that drives specific incorporation of RAP80 into BRCA1-A. RAP80 contains one SUMO-interacting motif (SIM), two ubiquitin-interacting motifs (UIMs), this AIR, and two zinc finger motifs (ZnF). The SIM and UIM domains recruit BRCA1-A to sites of DNA damage. The AIR is integral in the interaction of RAP80 with the ABRAXAS, MERIT40, and BRE subunits.