BRD4-BD1 complexed with diacetylated TOP2A

Bromodomain-containing protein 4 (BRD4) plays a vital role in gene expression as it acts as a transcriptional activator by recognising diacetylated lysine residues of its substrates such as acetylated histone tails on H3 and H4 histones. BRD4 is able to recognise these residues due to its two bromodomains, BD1 and BD2 which are histone readers. The most notable structural features of BD1 is explored in this protein tour which demonstrates the domain's ability to recognise and bind to its substrates through a combination of hydrophobic interactions and hydrogen bonding. References: 1. doi: 10.1074/jbc.M109.033712 2. doi: 10.1016/j.jmgm.2018.03.005 3. doi: 10.1016/j.molcel.2018.11.006