Bromodomain Factor 1 (Bdf1) Protein Interacts with Histones

Using a yeast two-hybrid assay we detected an interaction between the N-terminal region of histone H4 (amino acids 1--59) and a fragment of the bromodomain factor 1 protein (Bdf1p) (amino acids 304--571) that includes one of the two bromodomains of this protein. No interaction was observed using fragments of histone H4 sequence smaller than the first 59 amino acids. Recombinant Bdf1p (rBdf1p) demonstrates binding affinity for histones H4 and H3 but not H2A and H2B in vitro. Moreover, rBdf1p is able to bind histones H3 and H4 having different degrees of acetylation. Finally, we have not detected histone acetyltransferase activity associated with Bdf1p.