Bromodomain phylogenetic tree and domain structure of representative family members. (A) Domain organization of bromodomain-containing proteins for which fluorescence recovery after photobleaching (FRAP) assays are described herein. Protein length in amino acids is shown at the right of each protein. The identities of the different domains are given in the legend at the bottom. (B) The structure-based phylogenetic tree of the human bromodomain family according to Filippakopoulos et al. . The different families are named by Roman numerals (I to VIII). Proteins for which FRAP assays are described herein are highlighted in red.