KRAB (Krüppel-associated box) domain is a transcription repression module found in a subfamily of C2H2 zinc finger proteins (Bellefroid et al. 1999) and generally encoded by two exons, KRAB-A involved in repression and KRAB-B thought to act as enhancer for the A box repression. Whether or not the domain contains the A box, the B box, or both, it is always known as the KRAB domain (Urrutia 2006).
KRAB-A domain is present at N-terminus in KRBA2 variants of SCAN/KRAB cellular integrases. The presence of KRAB-A box in KRBA2 proteins with no additional zinc finger domain more than that of Integrase is strikingly particular and up to our knowledge no details on potential function has been reported.