The bromodomain as the acetyl-lysine binding domain in gene transcription

The bromodomain (BrD), a conserved structural module found in many chromatin- and transcription-associated proteins, is the primary reader of acetylated lysine residues on proteins. Since the discovery of this domain, the study of BrD-containing proteins has provided tremendous insights into many important mechanisms in chromatin biology and also shown that inhibitors of BrDs can be useful both as chemical tools in the laboratory and as therapeutics in the clinic. Brds often function in concert with other similar modular domains on chromatinassociated proteins, creating a very complex system of epigenetic regulation that is currently under investigation by numerous researchers. In this chapter, we take a closer look at the structure and functions of the BrD, as well as its interaction with other chromatin-associated modules and its overall role in disease biology.