Component of the BRCA1-A complex, at least composed of the BRCA1, BARD1, UIMC1/RAP80, FAM175A/Abraxas, BRCC3/BRCC36, BRE/BRCC45 and BABAM1/NBA1. In the BRCA1-A complex, interacts directly with FAM175A/Abraxas and BRE/BRCC45. Component of the BRISC complex, at least composed of the FAM175B/ABRO1, BRCC3/BRCC36, BRE/BRCC45 and BABAM1/NBA1 (By similarity).