FIG. 2.

Structure of the Brd4 gene and conservation of the Brd family. (a) Domain organizations of the different members of the Brd/fs(1)h family. A convenient nomenclature for the vertebrate members of this family based on the root fsrg (female sterile homeotic related) was proposed by Rhee et al. (32). However, here we use the nomenclature retained by the Mouse Gene Informatics Nomenclature Committee, who proposed the root Brd to designate the members of this bromodomain-containing family. Bromodomains are shown in blue, ET domains are shown in red, and the conserved 10-amino acid motif is shown in orange. Note that the hffsh sequence is only partial and terminates in the ET domain. (b) Similarity tree of the members of the Brd family (vertebrate members of the family are underlined). Note that Brd2/RING3 and Brd3/ORFX group together, in agreement with the important conservation of synteny observed between human chromosomes 6 and 9 (see reference 21 for review). Brd5/BRDT, the only member of the Brd family that exhibits a nonubiquitous pattern of expression (19), is found outside the mammalian group, suggesting a possible divergent function. Bdf1 and Bdf2 group together, suggesting a duplication after the separation between yeast and metazoans. Alignments of bromodomains also confirmed this result (data not shown). (c) Sequence comparison of the Ring3-like peptides (p66, p96a1, and p96a2) (isolated in the study cited in reference 18) with those of the four mammalian members of the Brd family. Arrows point at the sequences of the peptides and Brd4.