WSTF (Williams Syndrome Transcription Factor) is an extremely versatile protein and is involved in several molecular events including vitamin D dependent transcription, vitamin D metabolism, DNA repair and the transcription of the RNA polymerase I and III genes. WSTF is a subunit of three ATP-dependent chromatin remodeling complexes designated WINAC, WICH and B-WICH. In this study, the effect of the bromodomain of the WSTF protein and a histidine protein tag on the interaction of WSTF with its binding partners, SNF2h and nuclear myosin 1, in the B-WICH complex has been studied.