The acetylated N-terminal tails of histones are recognized by bromodomains (BDs), which act as a reader of lysine acetylation state. The bromodomains consist of about 110 residues and are structurally conserved. The BDs are present in many chromatin-associated factors, including nuclear histone acetyl transferases (HATs), chromatin remodeling factors and bromodomains and extra terminal (BET) domains family nuclear proteins. The tertiary structure of BD contains an α-helical bundle formed by four α-helices (αZ, αA, αB, αC). The BET family proteins (BRD2, BRD3, BRD4 and mBRDT) contain two tandem bromodomains (BD1 and BD2) and the C-terminal extra-terminal (ET) domain. It is also shown that BRD2 and bromodomain containing protein 4 (BRD4) associate with acetylated chromatin throughout the cell cycle while other non-BET bromodomain family members dissociate from the chromosomes during mitosis.  BET family proteins based on the BD structures acts the biological role of  potential therapeutic targets for diseases such as cancer, neurodegenerative disorders, inflammation and obesity.

References

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