One-domain interaction of histone H4 with nucleosomal core DNA is restricted to a narrow DNA segment

The interaction of histone H4 with DNA in the nucleosomal core particle has been studied by crosslinking DNA to proteins through their lysine residues. We have compared the crosslinked peptides of H4 at the detected DNA-binding sites: H4(55), H4(65), H4(88), located, respectively, at about 55, 65 and 88 nucleotides from the core DNA termini. For all these binding sites, the patterns of crosslinked peptides were shown to be very similar. This suggests the presence of a single DNA-binding domain in the H4 molecule. The H4-binding sites are located within a narrow DNA segment close to one another on the complementary strands across the DNA grooves, overlap with sites +/- 1 of the DNA sharp bending [(1984) Nature 311, 532-537] and with the strong binding sites for histone H3: H3(75) and H3(85).