Bromodomain, TFIID-like subfamily. Human TAFII250 (or TAF250) is the largest subunit of TFIID, a large multi-domain complex, which initiates the assembly of the transcription machinery. TAFII250 contains two bromodomains that specifically bind to acetylated histone H4. Bromodomains are 110 amino acid long domains, that are found in many chromatin associated proteins. Bromodomains can interact specifically with acetylated lysine.