Enables DNA-binding transcription factor binding activity and core promoter sequence-specific DNA binding activity. Involved in chromatin remodeling; negative regulation of transcription by RNA polymerase II; and positive regulation of transcription by RNA polymerase II. Located in nucleus. Part of ATAC complex. Is expressed in several structures, including embryonic dorsal epidermis; embryonic epipharynx; embryonic head epidermis; embryonic hypopharynx; and ganglia. Orthologous to human DR1 (down-regulator of transcription 1).