DsDNA-dependent ATPase which acts as a transcription termination factor by coupling ATP hydrolysis with removal of RNA polymerase II from the DNA template. May contribute to mitotic transcription repression. May also be involved in pre-mRNA splicing (By similarity). Interacts with CDC5L. Part of the spliceosome (By similarity). Cytoplasmic during interphase. Relocates to the nucleus as cells enter mitosis (By similarity). Belongs to the SNF2/RAD54 helicase family.