In eukaryotes, processes requiring access to DNA are inhibited by the struc
tural packaging of the genome. A number of specialized ATP-dependent chroma
tin remodeling enzymes have evolved to overcome this inhibition. One subset
of these enzymes, SWI/SNF, plays a critical role in the regulation of tran
scription, often functioning in concert with nuclear histone acetyltransfer
ases (HATs). It remains unknown how these activities are coordinated. Howev
er, recent results revealing that the bromodomain, a motif common in these
remodeling factors, constitutes an acetyl-lysine binding domain might provi
de insight into this process. Bromodomains may serve a role analogous to th
e signal transduction SH2 domain, by providing a means to recruit remodelin
g complexes to acetylated chromatin regions or to allosterically modify the
ir function post-recruitment.