Plays a role in chromatin remodeling and regulation of transcription. Acts as a chromatin reader that recognizes and binds acylated histones: binds histones that are acetylated and/or butyrylated. Binds acetylated histones H3 and H4. Binds butyrylated histone H4. The Bromo domain mediates interaction with histones that have acetylated lysine residues at specific positions. Also recognizes and binds histones that are butyrylated.